Ändra sökning
Avgränsa sökresultatet
123 1 - 50 av 137
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Träffar per sida
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
  • Standard (Relevans)
  • Författare A-Ö
  • Författare Ö-A
  • Titel A-Ö
  • Titel Ö-A
  • Publikationstyp A-Ö
  • Publikationstyp Ö-A
  • Äldst först
  • Nyast först
  • Skapad (Äldst först)
  • Skapad (Nyast först)
  • Senast uppdaterad (Äldst först)
  • Senast uppdaterad (Nyast först)
  • Disputationsdatum (tidigaste först)
  • Disputationsdatum (senaste först)
Markera
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 1.
    Chen, Yifeng
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Sun, Yunhao
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Yang, Zhuhong
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    CO2 separation using a hybrid choline-2-pyrrolidine-carboxylic acid/polyethylene glycol/water absorbent2020Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 257, artikel-id 113962Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Developing novel hybrid absorbents is essential for CO2 separation. In this study, the density and viscosity of a hybrid absorbent (choline-2-pyrrolidine-carboxylic acid/polyethylene glycol/water ([Cho][Pro]/PEG200/H2O)) were measured experimentally, and its CO2 solubility was also determined. The excess mole volume and excess Gibbs energy of activation of the hybrid absorbent were further estimated to understand the molecular structure and interactions between [Cho][Pro]/PEG200 and H2O. The CO2 solubilities in [Cho][Pro]/PEG200 and [Cho][Pro]/H2O were analyzed and described using the Redlich–Kwong non-random-two-liquid (RK-NRTL) model. Furthermore, the CO2 solubility in the hybrid absorbent was predicted using the RK-NRTL model and was compared with the new experimental results for verification. The effect of H2O on the CO2 absorption performance was further analyzed. The performance and cost of the hybrid absorbent were compared with those of other commercialized CO2 absorbents. In addition, the recyclability of the hybrid absorbent for CO2 separation was studied. The results of this study indicated that the hybrid absorbent could be promising for CO2 separation.

  • 2.
    Chen, Yifeng
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ma, Chunyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Zhuhong
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Thermodynamic study on aqueous polyethylene glycol 200 solution and performance assessment for CO2 separation2020Ingår i: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 504, artikel-id 112336Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To develop polyethylene glycol 200 (PEG200) and aqueous PEG200 solutions (PEG200/H2O) as solvents for CO2 separation, in this study, the available thermo-physical properties of PEG200 and PEG200/H2O measured experimentally were surveyed, evaluated, and correlated with empirical equations. The solubility of CO2 in PEG200 was also surveyed, evaluated and described with the Henry's law with the Poynting correction, while the solubilities of CH4 and N2 in PEG200 were determined experimentally and then described with the Henry's law. The CO2, CH4 and N2 solubilities in PEG200/H2O were measured and described with the Redlich–Kwong Nonrandom-Two-Liquid (RK-NRTL) model. In addition, the performances of PEG200, PEG200/H2O and other commercialized physical solvents for CO2 separation were discussed based on the properties, and the biogas upgrading was chosen as the example to quantitatively evaluate the performances of PEG200 and PEG200/H2O with process simulation and compared with the high pressure water scrubbing (HPWS). It shows that the total energy usage and the amount of recirculated solvent for biogas upgrading can decrease by 9.1% and 26.5%, respectively, when H2O is replaced by PEG200 completely.

  • 3.
    Dong, Yihui
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Materials-Oriented and Chemical Engineering Nanjing Tech University.
    Laaksonen, Aatto
    Department of Materials and Environmental Chemistry Arrhenius Laboratory Stockholm University. Centre of Advanced Research in Bionanoconjugates and Biopolymers Petru Poni Institute of Macromolecular Chemistry Aleea Grigore Ghica-Voda, Iasi, Romania. State Key Laboratory of Materials-Oriented and Chemical Engineering Nanjing Tech University, China.
    Cao, Wei
    State Key Laboratory of Tribology Tsinghua University, Beijing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented and Chemical Engineering Nanjing Tech University Nanjing, China.
    AFM Study of pH-Dependent Adhesion of Single Protein to TiO2 Surface2019Ingår i: Advanced Materials Interfaces, ISSN 2196-7350, Vol. 6, nr 14, artikel-id 1900411Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The effect of pH-induced electrostatic conditions on the molecular interaction force of a single lysozyme molecule with TiO2 is investigated using atomic force microscopy (AFM). The force between the charged or neutral lysozyme molecule and the TiO2 surface is measured at different pH from 3.6 to 10.8. It is found to be directly proportional to the contact area, given by an effective diameter of the lysozyme molecule, and is further qualitatively verified by the AFM-measured friction coefficients. The results of the Derjaguin–Landau–Verwey–Overbeek theory show that the pH can change the surface charge densities of both lysozyme and TiO2, but the molecular interaction force at different pH is only dependent on the pH-induced effective diameter of lysozyme. The molecular interaction forces, quantified at the nanoscale, can be directly used to design high-performance liquid chromatography measurements at macroscale by tuning the retention time of a protein under varied pH conditions. They can also be applied to develop a model for predicting and controlling the chromatographic separations of proteins.

  • 4.
    Liu, Yanrong
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    Nie, Yi
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    Lu, Xingmei
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    Zhang, Xiangping
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    He, Hongyan
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    Pan, Fengjiao
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    Zhou, Le
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    Liu, Xue
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zhang, Suojiang
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China .
    Cascade utilization of lignocellulosic biomass to high-value products2019Ingår i: Green Chemistry, ISSN 1463-9262, E-ISSN 1463-9270, Vol. 21, nr 13, s. 3499-3535Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Lignocellulosic biomass is a potential sustainable feedstock to replace fossil fuels. However, the complex structure of biomass makes it difficult to convert into high-value products. Utilization of lignocellulosic biomass in a green and effective way is of great significance for sustainable development. Based on the analysis of different options, we proposed that cascade utilization according to its composition, characteristics, and nature is the best way to utilize the lignocellulosic biomass. To promote the cascade utilization of lignocellulosic biomass, this article provides a review of the latest research results from the aspect of cascade utilization of lignocellulosic biomass covering the whole chain from pretreatment to high-value products, and the research on the non-conventional pretreatments including microwave irradiation, supercritical fluids, ultrasonic irradiation, electric field, hydrodynamic cavitation, and ionic liquids are presented in detail and evaluated by 4 proposed levels, and the newly developed high-value applications were further overviewed for lignin (carbon/graphene/carbon nano-tubes, dye dispersants, bioplastics, and aerogels), cellulose (cellulose-based ionic liquids, functional composites, adsorbent materials, carbon, and aerogels), and hemicellulose (films and pharmaceutical carriers), respectively. Finally, perspectives on the future research on the cascade utilization of lignocellulosic biomass are highlighted.

  • 5.
    Dong, Yihui
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Materials-Oriented and Chemical Engineering and Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Laaksonen, Aatto
    State Key Laboratory of Materials-Oriented and Chemical Engineering and Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, China. Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm, Sweden. Department of Chemistry, Ångström Laboratory, Uppsala University, Uppsala, Sweden. Centre of Advanced Research in Bionanoconjugates and Biopolymers, Petru Poni Institute of Macromolecular Chemistry Aleea Grigore Ghica-Voda, Iasi, Romania.
    Cao, Wei
    State Key Laboratory of Tribology, Tsinghua University, Beijing, China.
    An, Rong
    Herbert Gleiter Institute of Nanoscience, Nanjing University of Science & Technology, Nanjing, China.
    Lu, Linghong
    State Key Laboratory of Materials-Oriented and Chemical Engineering and Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented and Chemical Engineering and Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University, Nanjing, China.
    Determination of the small amount of proteins interacting with TiO2 nanotubes by AFM-measurement2019Ingår i: Biomaterials, ISSN 0142-9612, E-ISSN 1878-5905, Vol. 192, s. 368-376Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Detecting the small amounts of proteins interacting effectively with the solid film electrodes surface still remains a challenge. To address this, in this work, a new approach was proposed by the combination of the adhesion forces and the molecular interaction measured with AFM. Cytochrome c (Cyt C) interacting effectively with TiO2 nanotube arrays (TNAs) was chosen as a probe. The amounts of Cyt C molecules interacting effectively on TNAs surface (CTNA) range from 5.5×10-12 to 7.0×10-12 mol/cm2 (68.2-86.8 ng/cm2) and they are comparable with the values obtained by the electrochemistry method in the literature, in evidence of the accuracy of this AFM-based approach. The reliability of the proposed approach was further verified by conducting Surface Enhanced Raman Scattering (SERS) measurements and estimating the enhancement factor (EF). This interaction-based AFM approach can be used to accurately obtain the small amounts of adsorbed substances on the solid film electrodes surface in the applications such as biosensors, biocatalysis, and drug delivery, etc.

  • 6.
    Ma, Chunyan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Liu, Chang
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Lu, Xiaohua
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Erratum: Techno-economic analysis and performance comparison of aqueous deep eutectic solvent and other physical absorbents for biogas upgrading2019Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 235, s. 1669-1670Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The authors regret to inform that there are errors in the vertical axis of Figs. 4 and 5 as well as corresponding text. The corrected versions are given below. (Figure presented.) Fig. 4b: the left y-axis should read “$·Nm-3 CH4” instead of “k$·Nm-3 CH4”; The corrected version of Fig. 5 is shown below. Abstract: The text at the end of Abstract: ‘For the case with …respectively’ should read: “…with AQ50wt.%DESand PC decrease by…” instead of “…with PC and AQ50wt.%DES decrease by…” Section 3.3.2: The text at the end of paragraph 5: ‘The results of specific TAC of using…than that using water, respectively. ’ should read: “…using AQ50wt.%DES and PC decrease by ….” instead of “…using PC and AQDES decrease by…” “…using AQ50wt.%DES and PC increase up to…” instead of “…using PC and AQ50wt.%DESincrease up to…” The text at the end of paragraph 6: ‘While, using…raw biogas capacity. ’ should read: “…and 25% than water…” instead of “…and 50% than water…” Conclusion: The text at the end of paragraph 2: ‘The results of specific TAC of using PC …than PC should be developed.’ should read: “…using AQ50wt.%DES and PC decrease by…” instead of “…using PC and AQ50wt.%DES decrease by…” “…using AQ50wt.%DES and PC treated with…” instead of “…using PC and AQ50wt.%DES treated with…” The above errors do not reflect any calculations errors and do not compromise the findings of the paper. The authors would like to apologize for any inconvenience caused. 

  • 7.
    Li, Zheng
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Zhuhong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemical and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Experimental studies of air-blast atomization on the CO2 capture with aqueous alkali solutions2019Ingår i: Chinese Journal of Chemical Engineering, ISSN 1004-9541, E-ISSN 2210-321XArtikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, an air-blast atomizing column was used to study the CO2 capture performance with aqueous MEA (mono-ethanol-amine) and NaOH solutions. The effects of gas flow rate, the liquid to gas ratio (L/G), the CO2 concentration on the CO2 removal efficiency (η) and the volumetric overall mass transfer coefficient (KGav) were investigated. The air-blast atomizing column was also compared with the pressure spray tower on the studies of the CO2 capture performance. For the aqueous MEA and NaOH solutions, the experimental results show that the ηdecreases with increasing gas flow rate and CO2 concentration while it increases with increasing L/G. The effects on KGav are more complicated than those for η. When the CO2 concentration is low (3 v/v%), KGav increases with increasing gas flow rate while decreases with increasing L/G. However, when the CO2 concentration is high (9.5 v/v%), as the gas flow rate and L/G increases, KGav increases first and then decreases. The aqueous MEA solution achieves higher η and KGav than the aqueous NaOH solution. The air-blast atomizing column shows a good performance on CO2 capture.

  • 8.
    Han, Jiuli
    et al.
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China.
    Bai, Lu
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.
    Yang, Bingbing
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China.
    Bai, Yinge
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.
    Luo, Shuangjiang
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.
    Zeng, Shaojuan
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.
    Gao, Hongshuai
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China.
    Nie, Yi
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China. Zhengzhou Institute of Emerging Industrial Technology, Zhengzhou, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zhang, Suojiang
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China.
    Zhang, Xiangping
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, CAS Key Laboratory of Green Process and Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, China. School of Chemical Engineering, University of Chinese Academy of Sciences, Beijing, China.
    Highly Selective Oxygen/Nitrogen Separation Membrane Engineered Using a Porphyrin-Based Oxygen Carrier2019Ingår i: Membranes, ISSN 2077-0375, E-ISSN 2077-0375, Vol. 9, nr 9, artikel-id 115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Air separation is very important from the viewpoint of the economic and environmental advantages. In this work, defect-free facilitated transport membranes based on poly(amide-12-b-ethylene oxide) (Pebax-2533) and tetra(p-methoxylphenyl)porphyrin cobalt chloride (T(p-OCH3)PPCoCl) were fabricated in systematically varied compositions for O2/N2 separation. T(p-OCH3)PPCoCl was introduced as carriers that selectively and reversibly interacted with O2 and facilitated O2 transport in the membrane. The T(p-OCH3)PPCoCl had good compatibility with the Pebax-2533 via the hydrogen bond interaction and formed a uniform and thin selective layer on the substrate. The O2 separation performance of the thin film composite (TFC) membranes was improved by adding a small amount of the T(p-OCH3)PPCoCl and decreasing the feed pressure. At the pressure of 0.035 MPa, the O2 permeability and O2/N2 selectivity of the 0.6 wt % T(p-OCH3)PPCoCl/Pebax-2533 was more than 3.5 times that of the Pebax-2533 TFC membrane, which reached the 2008 Robeson upper bound. It provides a candidate membrane material for O2/N2 efficient separation in moderate conditions

  • 9.
    Liu, Sida
    et al.
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Li, Hang
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Chen, Yifeng
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Yang, Zhuhong
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Wang, Honglin
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Improved CO2 separation performance of aqueous choline-glycine solution by partially replacing water with polyethylene glycol2019Ingår i: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 495, s. 12-20Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Aqueous choline-glycine ([Cho][Gly]) solution is a potential candidate for CO2separation owing to its excellent absorption performance and biodegradability. Moreover, the aqueous solution is easy to volatilize at high temperatures. In this work, H2O was partially replaced with polyethylene glycol (PEG200) and the effect of PEG200 on the CO2 separation performance in [Cho][Gly])/H2O was investigated. The viscosity of [Cho][Gly]/H2O/PEG200 and CO2 solubility in the solution were determined experimentally in the temperature range 308.15–338.15 K at pressures ≤6.5 bar. Further, the measured CO2 solubility was fitted with the reaction equilibrium thermodynamic model and the CO2 desorption enthalpy was estimated. The regeneration performance of [Cho][Gly]/H2O/PEG200 was also evaluated. The results revealed that [Cho][Gly]/H2O/PEG200 has a low CO2desorption enthalpy and high regeneration efficiency. Particularly, [Cho][Gly]/H2O/PEG200 with 30 wt% PEG200 has a high regeneration efficiency of 95%. Owing to its physical-chemical properties and CO2 separation performance, [Cho][Gly]/H2O/PEG200 shows great potential as an absorbent for CO2 separation.

  • 10.
    Bülow, M.
    et al.
    TU Dortmund, Dortmund, Germany.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Held, C.
    TU Dortmund, Dortmund, Germany.
    Incorporating a concentration-dependent dielectric constant into ePC-SAFT. An application to binary mixtures containing ionic liquids2019Ingår i: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 492, s. 26-33Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Primitive thermodynamic models for electrolyte solutions require the dielectric constant ε. This property strongly depends on the concentration of the electrolytes in the mixture. Neglecting this dependency might be reasonable for modeling solutions at low electrolyte concentrations. However, in solutions containing ionic liquids (ILs) and especially for the calculation of liquid-liquid equilibria (LLE) of systems with ILs, liquid phases often contain high IL concentrations. At such conditions, neglecting the influence of concentration on ε is an oversimplification. In this work, an approach to account for the concentration-dependent dielectric constant within the Debye-Hückel theory was implemented into electrolyte Perturbed-Chain Statistical Associating Fluid Theory (original ePC-SAFT). This new approach was then applied to model LLE of binary mixtures containing water and commonly used hydrophobic ILs. These common ILs are comprised of the IL-cations [C n mim] + , [C n py] + , [C n mpy] + , [C n mpyr] + , [C 4 m 4 py] + and the IL-anions [BF 4 ] - , [NTf 2 ] - , [PF 6 ] - , [TFO] - . The LLE of binary mixtures water + IL were modeled at ambient pressure and different temperatures with the new ePC-SAFT and with the original ePC-SAFT [Ji et al. DOI: 10.1016/j.fluid.2012.05.029] without the concentration-dependent ε. Overall, the new approach within ePC-SAFT shows superior modeling as well as correlation capability compared to original ePC-SAFT, which was concluded by comparing both models with LLE data from literature. 

  • 11.
    Huangfu, Changan
    et al.
    State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Dong, Yihui
    State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wu, Na
    State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Mechanistic Study of Protein Adsorption on Mesoporous TiOin Aqueous Buffer Solutions2019Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 35, nr 34, s. 11037-11047Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Protein adsorption is of fundamental importance for bioseparation engineering applications. In this work, a series of mesoporous TiO2 with various geometric structures and different aqueous buffer solutions were prepared as platforms to investigate the effects of the surface geometry and ionic strength on the protein adsorptive behavior. The surface geometry of the TiO2 was found to play a dominant role in the protein adsorption capacity when the ionic strength of buffer solutions is very low. With the increase in ionic strength, the effect of the geometric structure on the protein adsorption capacity reduced greatly. The change of ionic strength has the highest significant effect on the mesoporous TiO2 with large pore size compared with that with small pore size. The interaction between the protein and TiO2 measured with atomic force microscopy further demonstrated that the adhesion force induced by the surface geometry reduced with the increase in the ionic strength. These findings were used to guide the detection of the retention behavior of protein by high-performance liquid chromatography, providing a step forward toward understanding the protein adsorption for predicting and controlling the chromatographic separation of proteins.

  • 12.
    Sun, Yunhao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Schemann, Arne
    Laboratory of Thermodynamics, Department of Biochemical and Chemical Engineering, TU Dortmund, Dortmund, Germany.
    Held, Christoph
    Laboratory of Thermodynamics, Department of Biochemical and Chemical Engineering, TU Dortmund, Dortmund, Germany.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, PR China.
    Shen, Gulou
    Department of Chemical Engineering, Jiangsu Provincial Engineering Laboratory for Advanced Materials of Salt Chemical Industry, Huaiyin Institute of Technology, Huaian, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Modeling Thermodynamic Derivative Properties and Gas Solubility of Ionic Liquids with ePC-SAFT2019Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 58, nr 19, s. 8401-8417Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, the ion-specific electrolyte perturbed-chain statistical associating fluid theory (ePC-SAFT) was extended to predict the second-order thermodynamic derivative properties and gas solubility of the ionic liquids (ILs) containing one of the IL cations ([Cnmim]+, [Cnpy]+, [Cnmpy]+, [Cnmpyr]+, and [THTDP]+) and one of the IL anions ([Tf2N], [PF6], [BF4], [tfo], [DCA], [SCN], [C1SO4], [C2SO4], [eFAP], Cl, [Ac], and Br). The ideal-gas isobaric heat capacities of ILs were estimated by the group contribution method for obtaining the heat capacity. The model prediction results were compared with the available experimental data, and the comparison shows that the ePC-SAFT prediction is reliable for most ILs. Furthermore, one adjustable ion-specific binary interaction parameter between the IL ion and CO2 can be used to further improve the model prediction performance for the CO2 solubility in ILs.

  • 13.
    Chen, Yifeng
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Zhuhong
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Novel Solvent for CO2 Capture2019Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 158, s. 5124-5129Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    To develop novel solvent for CO2 capture, CO2 absorption performance using the aqueous of polyethylene glycol 200 (PEG200) and choline-2-pyrrolidinecarboxylic acid ([Cho][Pro]) was studied and evaluated systematically in this work, in which the critical properties of PEG200 were estimated with group contribution method, and other thermo-physical properties were determined experimentally or taken from literatures directly and then correlated with empirical equations. The CO2 solubility in PEG200 was measured and represented with the Henry’s law and Poynting correction, while the measured CO2 solubility in PEG200/H2O was correlated with RK-NRTL model. [Cho][Pro] was used as the chemical ingredient to enhance the absorption capacity and rate of CO2 in [Cho][Pro]/PEG200/H2O, and the corresponding properties and CO2 solubility were studied. The kinetic parameters, such as enhancement factor (E), reaction rate constant (k), and activation energy (Ea) of CO2 in [Cho][Pro]/PEG200/H2O were estimated from the new experimental data measured in this work and compared with the commercialized aqueous MEA solution. The process simulation and pilot-testing based on [Cho][Pro]/PEG200/H2O will be performed in the future.

  • 14.
    Liu, Yaoqian
    et al.
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Chen, Jingjing
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wang, Changsong
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Reducing the agitation power consumption in anaerobic digestion of corn straw by adjusting the rheological properties2019Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 158, s. 1267-1272Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Agitation power consumption (P) in the anaerobic digestion of biogas plants is a major part of the electric energy consumption. To reduce P by adjusting the rheological properties, in this work, the rheological properties of corn straw slurry were studied systematically with the consideration of the effects of TS, temperature and particle sizes. The P was calculated based on the rheological behaviour of corn straw slurry. The investigation shows that the thermophilic digestion is effective only for the slurry with a relatively high TS. The size-reduction is more effective at higher TS compared to the option of increasing temperature in order to improve the agitation power efficiency, and the value of P can be reduced by up to 48.11 %. Since the size-reduction can also increase the methane yield, the adjustment of particle sizes is a promising option to save P, especially at higher TS.

  • 15.
    Li, Zheng
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Zhuhong
    Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    Nanjing Tech University, Nanjing, China.
    Study of CO2 absorption/desorption behaviors in aqueous (2-hydroxyethyl)-trimethyl-ammonium (S)-2-pyrrolidine-carboxylic acid salt ([Cho][Pro]) + K2CO3 solutions2019Ingår i: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 83, s. 51-60Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, an aqueous (2-hydroxyethyl)-trimethyl-ammonium (S)-2-pyrrolidinecarboxylic acid salt ([Cho][Pro]) + K2CO3 solution was studied as a novel absorbent for CO2 capture, and the kinetics and mechanism of the CO2 absorption/desorption process were systematically investigated. Adding [Cho][Pro] to the aqueous K2CO3 solution improved the absorption rate of the solution during the initial stage, and the apparent CO2 absorption rate increased as the concentration of [Cho][Pro] increased. Meanwhile, equilibrium was reached faster when [Cho][Pro] was added, and a tradeoff was noticed between the apparent absorption rate constant and equilibrium absorption amount. The desorption rates of the CO2-rich aqueous [Cho][Pro] + K2CO3 solutions were higher than that of the aqueous [Cho][Pro] solution at 363.15 K, and the highest apparent desorption rate constant was achieved for the aqueous 20 wt.% [Cho][Pro] + 10 wt.% K2CO3 solution. A further study on the aqueous 20 wt.% [Cho][Pro] + 10 wt.% K2CO3 solution indicated that the desorption amount increased with the increase in the temperature from 348.15 to 365.15 K. Moreover, with further increase in temperature, the desorption amount exhibited a lower increasing rate when temperature was higher than 361.15 K. The 20 wt.% [Cho][Pro] + 10 wt.% K2CO3 absorbent exhibited more stable regeneration performance after 7 cycles and lower desorption activation energy than the aqueous 30 wt.% monoethanolamine (MEA) and 30 wt.% [Cho][Pro] solutions as well as higher working capacity compared to the aqueous 30 wt.% [Cho][Pro] solution.

  • 16.
    Liu, Yanrong
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China.
    Nie, Yi
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China.
    Pan, Fengjiao
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China.
    Zhou, Le
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Kang, Zhaoqing
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China.
    Zhang, Suojiang
    CAS Key Laboratory of Green Process and Engineering, Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex Systems, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, PR China.
    Study on ionic liquid/cellulose/coagulator phase diagram and its application in green spinning process2019Ingår i: Journal of Molecular Liquids, ISSN 0167-7322, E-ISSN 1873-3166, Vol. 289, artikel-id 111127Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, the cellulose phase separation behavior was investigated by using ionic liquids (ILs) as novel solvents to acquire a green process for cellulose fiber spinning. The cloud point titration method combined with the turbidity correlation equation was used to obtain the ternary diagram of IL/cellulose/coagulator throughout the whole compositional range. The effects of the type of ILs, the cellulose materials, the kind of coagulators and the regeneration temperatures for cellulose fiber manufacturing process on the phase separation behavior were studied systematically. It was found that the linearized cloud point (LCP) curve correlation fits to experimental data well and can be used to quantify the optimized coagulator, and among the studied cases, the system of [EMIM]DEP, cotton pulp and water with the regeneration temperature at 298.15 K is the best. Meanwhile, COSMO-RS was used to predict the interaction between solvent, cellulose and coagulator, and the comparison with the LCP correlation shows good agreement. The crystal structure of the regenerated cotton pulp was determined with XRD, and the result evidences that the crystal structure of the regenerated cellulose transforms from cellulose I to cellulose II. The crystallinity decreases from 96.0% (raw cotton pulp) to 85.6% after 24 h dissolution in [EMIM]DEP at 363.15 K, and it has a slight deviation from 24 h to 72 h, which illustrates that the spinning process can run continuously at 363.15 K when using [EMIM]DEP as the solvent.

  • 17.
    Li, Biao
    et al.
    Key Laboratory of Material-Oriented and Chemical Engineering, Nanjing Tech University.
    Chen, Yifeng
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Yang, Zhuhong
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Thermodynamic study on carbon dioxide absorption in aqueous solutions of choline-based amino acid ionic liquids2019Ingår i: Separation and Purification Technology, ISSN 1383-5866, E-ISSN 1873-3794, Vol. 214, s. 128-138Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Five choline-based amino acid ionic liquids ([Cho][AA]s) are prepared by neutralization between choline hydroxide and amino acids with different molecular weight and alkalinity. Solubility of CO2 in 30 wt% aqueous solutions of these five [Cho][AA]s has been measured at temperatures from 303.15 to 333.15 K and pressures up to 7 bar. Based on the zwitterion mechanism, the solubility of CO2 in aqueous [Cho][AA]s solutions is correlated with a reaction equilibrium thermodynamic model (RETM). The corresponding thermodynamic parameters, such as Henry’s law constants, reaction equilibrium constants, and enthalpy of physical dissolution and chemical reaction are all calculated and compared to evaluate the CO2 absorption performance in aqueous solutions of five [Cho][AA]s. Meanwhile, the recyclability of the aqueous solution with 30 wt% [Cho][Lys] has been also investigated.

  • 18.
    Liu, Yaoqian
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Chen, Jingjing
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Song, Jian
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Hai, Zhong
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wang, Changsong
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Adjusting the rheological properties of corn-straw slurry to reduce the agitation power consumption in anaerobic digestion2018Ingår i: Bioresource Technology, ISSN 0960-8524, E-ISSN 1873-2976, Vol. 272, s. 360-369Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Agitation power consumption (P) in the anaerobic digestion of biogas plants is a major consumer of electric energy. To reduce P by adjusting the rheological properties, in this work, the rheological properties of the corn-straw slurry were studied systematically considering the effects of TS, temperature and particle-size, and P was calculated based on the rheological behavior of the corn-straw slurry. The investigation shows that the corn-straw slurry is a non-Newtonian fluid and exhibit shear-thinning behavior, and the rheological properties can be well described with the power law model. The size-reduction is more effective compared to the option of temperature-increase to improve the agitation power efficiency, and the value of P can be reduced by up to 48.11 %. Since the size-reduction can also increase the methane yield, the reduction of the particle-size is a promising option to save P, especially at relatively high TSs and for the thermophilic AD process.

  • 19.
    Carvalho, Lara
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Furusjö, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. IVL – Swedish Environmental Institute, Stockholm, Sweden.
    Ma, Chunyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria.
    Hedlund, Jonas
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Grahn, Mattias
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Öhrman, Olov G. W.
    IVL – Swedish Environmental Institute, Stockholm, Sweden;RISE Energy Technology Center AB, Piteå, Sweden.
    Wetterlund, Elisabeth
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria.
    Alkali enhanced biomass gasification with in situ S capture and a novel syngas cleaning: Part 2: Techno-economic analysis2018Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 165, nr Part B, s. 471-482Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Previous research has shown that alkali addition has operational advantages in entrained flow biomass gasification and allows for capture of up to 90% of the biomass sulfur in the slag phase. The resultant low-sulfur content syngas can create new possibilities for syngas cleaning processes. The aim was to assess the techno-economic performance of biofuel production via gasification of alkali impregnated biomass using a novel gas cleaning systemcomprised of (i) entrained flow catalytic gasification with in situ sulfur removal, (ii) further sulfur removal using a zinc bed, (iii) tar removal using a carbon filter, and (iv) CO2 reductionwith zeolite membranes, in comparison to the expensive acid gas removal system (Rectisol technology). The results show that alkali impregnation increases methanol productionallowing for selling prices similar to biofuel production from non-impregnated biomass. It was concluded that the methanol production using the novel cleaning system is comparable to the Rectisol technology in terms of energy efficiency, while showing an economic advantagederived from a methanol selling price reduction of 2–6 €/MWh. The results showed a high level of robustness to changes related to prices and operation. Methanol selling prices could be further reduced by choosing low sulfur content feedstocks.

  • 20.
    Furusjö, Erik
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. IVL Swedish Environmental Research Institute, Climate & Sustainable Cities.
    Ma, Chunyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Carvalho, Lara
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wetterlund, Elisabeth
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Alkali enhanced biomass gasification with in situ S capture and novel syngas cleaning: Part 1: Gasifier performance2018Ingår i: Energy, ISSN 0360-5442, E-ISSN 1873-6785, Vol. 157, s. 96-105Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Previous research shows that alkali addition in entrained flow biomass gasification can increase char conversion and decrease tar and soot formation through catalysis. This paper investigates two other potential benefits of alkali addition: increased slag flowability and in situ sulfur capture.

    Thermodynamic equilibrium calculations show that addition of 2–8% alkali catalyst to biomass completely changes the chemical domain of the gasifier slag phase to an alkali carbonate melt with low viscosity. This can increase feedstock flexibility and improve the operability of an entrained flow biomass gasification process. The alkali carbonate melt also leads to up to 90% sulfur capture through the formation of alkali sulfides. The resulting reduced syngas sulfur content can potentially simplify gas cleaning required for catalytic biofuel production.

    Alkali catalyst recovery and recycling is a precondition for the economic feasibility of the proposed process and is effected through a wet quench. It is shown that the addition of Zn for sulfur precipitation in the alkali recovery loop enables the separation of S, Ca and Mg from the recycle. For high Si and Cl biomass feedstocks, an alternative separation technology for these elements may be required to avoid build-up.

  • 21.
    Zhang, Yingying
    et al.
    Department of Material and Chemical Engineering, Zhengzhou University of Light Industry, 450002 Zhengzhou, China.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, 210009 Nanjing, China.
    Choline-based deep eutectic solvents for CO2 separation: Review and thermodynamic analysis2018Ingår i: Renewable & sustainable energy reviews, ISSN 1364-0321, E-ISSN 1879-0690, Vol. 97, s. 436-455Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CO2 separation plays an important role in energy saving and CO2 emission reduction, both of which are necessary to address the issue of global warming. Ionic liquids (ILs) have been proposed to be “green” solvents for CO2 separation. Unfortunately, the high cost, toxicity, and poor biodegradability of these compounds limit their large-scale application. Deep eutectic solvents (DESs) were recently considered a new type of IL with additional advantages in terms of cost, environmental impact, and synthesis. DESs based on choline salts (i.e., choline-based DESs) are promising candidates for CO2 separation. In this work, the microstructures, physicochemical properties, and water effect of choline-based DESs are surveyed and compared with those of conventional ILs. The properties of choline-based DESs are similar to those of conventional ILs, but research on the latter remains limited. Further study on the microstructures, properties, and separation performance of choline-based DESs considering dynamic factors must be carried out through experimental measurements and model development. Thermodynamic analysis based on Gibbs free energy change is conducted to investigate the performances of choline-based-DESs during CO2 separation from biogas. Choline-based-DESs are screened on the basis of energy use and amount of absorbent needed. The performances of the screened choline-based-DESs are further compared with those of conventional ILs screened in our previous work, as well as commercial CO2 absorbents. Comparisons indicate that the screened DES-based absorbents show great application potential due to their nonvolatility, low energy use, or low amount required. The performances of physical choline-based-DES and 30 wt% MEA for CO2 separation from other gas streams (e.g., flue gas, lime kiln gas, and bio-syngas) are discussed. Considering the high amounts of physical absorbents required to enable separation, further study with techno-economic analysis needs to be carried out.

  • 22.
    Shen, Gulou
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Jiangsu Provincial Engineering Laboratory for Advanced Materials of Salt Chemical Industry, Huaiyin Institute of Technology, Huaian.
    Laaksonen, Aatto
    Stockholm University, Arrhenius Laboratory, Department oft Materials & Environmental Chemistry.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Developing Electrolyte Perturbed-Chain Statistical Associating Fluid Theory Density Functional Theory for CO2 Separation by Confined Ionic Liquids2018Ingår i: The Journal of Physical Chemistry C, ISSN 1932-7447, E-ISSN 1932-7455, Vol. 122, nr 27, s. 15464-15473Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The electrolyte perturbed-chain statistical associating fluid theory (ePC-SAFT) classical density functional theory (DFT) was developed to describe the behavior of pure ionic liquid (IL) and CO2/IL mixture confined in nanopores, in which a new ionic functional based on the ionic term from ePC-SAFT was proposed for electrostatic free-energy contribution. The developed model was verified by comparing the model prediction with molecular simulation results for ionic fluids, and the agreement shows that the model is reliable in representing the confined behavior of ionic fluids. The developed model was further used to study the behavior of pure IL and CO2/IL mixture in silica nanopores where the IL ions and CO2 were modeled as chains that consisted of spherical segments with the parameters taken from the bulk ePC-SAFT. The results reveal that the nanoconfinement can lead to an increased CO2 solubility, and the solubility increases with increasing pressure. The averaged density of pure IL and solubility of CO2 are strongly dependent on pore sizes and geometries. In addition, the choice of IL ions is very important for the CO2 solubility. Overall, the modeling results for silica-confined systems are consistent with available molecular simulation and experimental results.

  • 23.
    Gao, Qingwei
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University.
    Zhu, Yudan
    College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zhu, Wei
    College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University.
    Lu, Linghong
    College of Chemical Engineering, State Key Laboratory of Materials-oriented Chemical Engineering, Jiangsu National Synergetic Innovation Center for Advanced Materials (SICAM), Nanjing Tech University.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Effect of water concentration on the microstructures of choline chloride/urea (1:2) /water mixture2018Ingår i: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 470, s. 134-139Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Molecular dynamics was utilized to investigate the properties of ChCl/urea (1:2)/water mixtures from pure ChCl/urea to infinitely dilute solution. To further study the mechanism at molecular scale, the local microstructure variation in the mixtures with the increase of water content was analyzed in detail. Simulation results showed that neither choline cations nor chloride anions are saturated by the coordinated water molecules, even when the water molar fraction reaches 0.9. The hydration number proportions for different ions indicated that the hydration strength of chloride anion is stronger than that of choline cation, which may play greater effects on the properties of mixtures. This result is further confirmed by the analysis of interaction energy between cation (anion) and water molecules. Moreover, the ion pairing between choline cations and chloride anions is a dominant factor to affect the solution properties at lower water content, whereas the hydration turns to be the dominant factor with increasing water content. The competition between ion pairing and ionic hydration could be the intrinsic mechanism resulting in non-ideal properties.

  • 24.
    Sun, Yunhao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Shen, Gulou
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Department of Chemical Engineering, Jiangsu Provincial Engineering Laboratory for Advanced Materials of Salt Chemical Industry, Huaiyin Institute of Technology, Huaian.
    Held, Christoph
    Laboratory of Thermodynamics, Department of Biochemical and Chemical Engineering, TU Dortmund.
    Feng, Xin
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing .
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Modeling Viscosity of Ionic Liquids with Electrolyte Perturbed-Chain Statistical Associating Fluid Theory and Free Volume Theory2018Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 57, nr 26, s. 8784-8801Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Viscosity is one of the most important physical properties when developing ionic liquids (ILs) for industrial applications such as CO2 separation. The viscosities of ILs have been measured experimentally, while the modeling work is still limited. In this work, the electrolyte perturbed-chain statistical associating fluid theory (ePC-SAFT) was combined with the free volume theory (FVT) to model the viscosities of pure ILs and IL mixtures up to high pressures and temperatures, in which the ePC-SAFT was used to calculate the density as inputs for modeling the viscosity of ILs with FVT. The ILs under consideration contain one of the IL cations [Cnmim]+, [Cnpy]+, [Cnmpy]+, [Cnmpyr]+, or [THTDP]+ and one of the IL anions [Tf2N], [PF6], [BF4], [tfo], [DCA], [SCN], [C1SO4], [C2SO4], [eFAP], Cl, [Ac], or Br. In total, 89 ILs were considered combined with a thorough literature survey of the available experimental viscosity data and evaluation. The comparison with the available experimental viscosities shows that the model can provide reliable representation and prediction for most of the pure ILs in a wide temperature and pressure range, and it can be further used to predict and describe the viscosity of IL mixtures reliably.

  • 25.
    Ma, Chunyan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Liu, Chang
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Lu, Xiaohua
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Techno-economic analysis and performance comparison of aqueous deep eutectic solvent and other physical absorbents for biogas upgrading2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 225, s. 437-447Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biogas has been considered as an alternative renewable energy, and CO2 removal from raw biogas (i.e. biogas upgrading) is needed for producing biomethane to be used as vehicle fuels or injected into the natural gas grid. Biogas upgrading with physical absorbents, such as water and other commercial organic solvents, is simple, efficient and with low energy requirements for regeneration. Recently, deep eutectic solvents (DESs) with nonvolatility, nonflammability and low price have been reported as promising alternatives to replace conventional physical absorbents in many research areas including biogas upgrading. However, the performances of these physical solvents including conventional physical absorbents and DES-based solvents have not been evaluated and compared with each other. In this work, the properties of 4 physical solvents (i.e. water, dimethyl ether of polyethylene glycol (DEPG), propylene carbonate (PC), and aqueous DES (AQDES)) were compared. Furthermore, a conceptual process was developed to upgrade biogas with these solvents and simulated based on Aspen Plus in order to conduct performance comparison. The simulation results of energy utilization, the amount of recirculated solvents and the diameters of absorber and desorber were analyzed and compared based on equilibrium and rate-based approaches, respectively. The simulation results based on the rate-based approach were further used to estimate the costs of biogas upgrading process with a same raw biogas capacity for comparison. Meanwhile, the specific cost of biogas upgrading process with a same size of equipment was also evaluated. The results show that the CO2 solubility, selectivity and viscosity are three more important properties, providing valuable information for developing novel physical solvents for CO2 separation. The simulation results show that the equilibrium and rate-based approaches result in different conclusions, especially when the solvent viscosity is relatively high, and the rate-based approach is preferable. Based on the simulation results from the rate-based approach, the performances of AQDES and PC are similar with a same amount of energy utilization, that is around 11% lower than water, and DEPG is inferior to water. For the case with the same gas capacity, the total annual costs of biogas upgrading process with these solvents show the following order: DEPG > AQ60wt.%DES > water > AQ50wt.%DES ≈ PC. For the case with the same size of equipment, compared to water, the total specific costs of biogas upgrading process with PC and AQ50wt.%DES decrease by about 30% and 45%, respectively, and the treated biogas capacities increase to 1.5 and 2 times, respectively. In general, both PC and AQ50wt.%DES show better performance than the other solvents. Considering that DES is an environmentally benign solvent, and the performance of DES can be greatly improved by further designing, it is more promising

  • 26.
    Xie, Yujiao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Björkmalm, Johanna
    SP Technical Research Institute of Sweden, Box 857, 501 15 Borås.
    Ma, Chunyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Willquist, Karin
    SP Technical Research Institute of Sweden, Box 857, 501 15 Borås.
    Yngvesson, Johan
    SP Technical Research Institute of Sweden, Box 857, 501 15 Borås.
    Wallberg, Ola
    Department of Chemical Engineering, Lund University.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Techno-economic evaluation of biogas upgrading using ionic liquids in comparison with industrially used technology in Scandinavian anaerobic digestion plants2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 227, s. 742-750Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The process of biogas upgrading with ionic liquids, i.e. pure 1-butyl-3-methylimidazolium bis(trifluoro-methylsulfonyl)imide ([bmim][Tf2N]), aqueous choline chloride/urea (ChCl/Urea), and aqueous 1-allyl-3-methyl imidazole formate ([Amim][HCOO]), was simulated in Aspen Plus and compared with the conventional water scrubbing upgrading technique. The comparisons of the performances on the amount of recirculated solvents and energy usage show the following order: aqueous [Amim][HCOO]<aqueous ChCl/Urea<[bmim][Tf2N]<water. Six different co-digestion plants (anaerobic digestion, AD, plants) were surveyed to acquire data for comparison. The selected plants had different raw biogas production capacities and produced gas with differing methane content. The data confirmed the simulation results that the type of substrate and the configuration of AD process are two factors affecting energy usage, investment cost, as well as operation and maintenance costs for the subsequent biogas upgrading. In addition, the simulation indicated that the energy usage of the ionic liquid-based upgrading was lower than that of the conventional upgrading techniques in Scandinavian AD plants. The estimated cost including investment, operation and maintenance for the ionic liquid technology showed to be lower than that for the water scrubbing upgrading process.

  • 27.
    Ma, Chunyan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 210009, China.
    Laaksonen, Aatto
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, 210009, China. Department of Materials and Environmental Chemistry, Arrhenius Laboratory, Stockholm University, Stockholm, Sweden. Department of Chemistry-Ångström Laboratory, Uppsala University, Uppsala, Sweden. Centre of Advanced Research in Bionanoconjugates and Biopolymers, Petru Poni Institute of Macromolecular Chemistry Aleea Grigore Ghica-Voda, Iasi, Romania.
    Liu, Chang
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    Lu, Xiaohua
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, China.
    The peculiar effect of water on ionic liquids and deep eutectic solvents.2018Ingår i: Chemical Society Reviews, ISSN 0306-0012, Vol. 47, nr 23, s. 8685-8720Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Ionic liquids (ILs) and deep eutectic solvents (DESs) have been suggested as eco-friendly alternatives to organic solvents. A trace amount of water is often unavoidable as impurity, and water is also added on purpose to reduce their problematically high viscosity and lower their high price. Understanding the distinct effects of water on the properties of ILs/DESs is highly important. In this review, we collect published experimental and theoretical results for IL/DES-H2O systems at varied water concentrations and analyze them. Results from mechanistic studies, thermodynamic modelling and advanced experiments are collected and critically discussed. Six commonly studied IL/DES-H2O systems were selected to map experimental observations onto microscopic results obtained in mechanistic studies. A great variety of distinct contours of the excess properties can be observed over the entire compositional range, indicating that the properties of IL/DES-H2O systems are highly unpredictable. Mechanistic studies clearly demonstrate that the added H2O rapidly changes the heterogeneous 3D structures of pure ILs/DESs, leading to very different properties and behaviour. There are similarities between aqueous electrolytes and IL/DES solutions but the bulky and asymmetric organic cations in ILs/DESs do not conform to the standard salt dissolution and hydration concepts. Thermodynamic modelling previously assumes ILs/DESs to be either a neutral ion-pair or completely dissociated ions, neglecting specific ion hydration effects. A new conceptual framework is suggested for thermodynamic modelling of IL/DES-H2O binary systems to enable new technologies for their practical applications.

  • 28.
    Zhang, Yingying
    et al.
    Department of Material and Chemical Engineering, Zhengzhou University of Light Industry.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Xie, Yujiao
    School of Chemical Engineering, Shandong University of Technology.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Thermodynamic analysis of CO2 separation from biogas with conventional ionic liquids2018Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 217, s. 75-87Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CO2 separation plays an important role in energy saving and CO2 emission reduction to address global warming. Ionic liquids (ILs) have been proposed as potential absorbents for CO2 separation, and a large amount of ILs have been synthesized to achieve this purpose. To screen ILs for CO2 separation, CO2 absorption capacity/selectivity and energy use have been considered, whereas the required amount of IL has been seldom involved. In this work, CO2 separation from biogas with 30 conventional ILs was analyzed theoretically on the basis of the Gibbs free energy change combining the amount of IL needed and the energy use. The desorption temperature was estimated from the absorption pressure, and then the amount of IL needed and the energy use were calculated. Thermodynamic analysis shows that the absorption pressure and the desorption temperature need to be changed to achieve optimal separation. Several ILs were screened with certain criteria, namely, the amount of IL needed and energy use. The performance of the screened ILs was compared with that of commercial CO2 absorbents (30 wt% MEA, 30 wt% MDEA, DEPG, and water). The comparison with DEPG and water shows that the screened physical ILs are promising for IL-based technologies because of their advantages of negligible vaporization enthalpy, low amount of absorbent needed, or low energy use. A comparison with 30 wt% MEA and 30 wt% MDEA indicates that chemical IL has negligible vaporization enthalpy and low energy use. These findings show that the screened ILs are promising for CO2 separation from biogas.

  • 29.
    Xie, Yujiao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Raut, Dilip G.
    Chemical-Biological Centre, Technical Chemistry, Department of Chemistry, Umeå University.
    Samikannu, Rakesh
    Chemical-Biological Centre, Technical Chemistry, Department of Chemistry, Umeå University.
    Mikkola, Jyri-Pekka
    Technical Chemistry, Department of Chemistry, Chemical-Biological Centre, Umeå University.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    A Thermodynamic Study of Aqueous 1-Allyl-3-Methylimidazolium Formate Ionic Liquid as a Tailored Sorbent for Carbon Dioxide Separation2017Ingår i: Energy Technology, ISSN 2194-4288, Vol. 5, nr 8, s. 1464-1471Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, aqueous 1-allyl-3-methylimidazolium formate ([Amim][HCOO]) was studied as a potential sorbent for CO2 separation. The density and viscosity of aqueous [Amim][HCOO] were measured at temperatures ranging from 293.15 to 333.15 K at atmospheric pressure. The solubility of CO2 and CH4 in dry [Amim][HCOO] as well as the CO2 solubility in aqueous [Amim][HCOO] were measured at pressures up to 1.8 MPa and temperatures of 298.2, 313.2, and 333.2 K. The results showed that the density and viscosity of aqueous [Amim][HCOO] as well as the CO2 solubility in aqueous [Amim][HCOO] decreased upon increasing the water concentration and temperature. The viscosity was very sensitive to the water concentration. The experimental density and viscosity of aqueous [Amim][HCOO] were fitted to semiempirical equations, and the excess molar volume and viscosity deviations were calculated to investigate the interaction between the [Amim][HCOO] ionic liquid and water. The experimental vapor–liquid equilibrium was represented with the nonrandom two-liquid and Redlich–Kwong model. The model parameters can be further implemented into Aspen Plus software to conduct process simulations.

  • 30.
    Sarmad, Shokat
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Mikkola, Jyri-Pekka
    Technical Chemistry, Department of Chemistry, Chemical-Biological Centre, Umeå University, Umeå, Sweden.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Carbon Dioxide Capture with Ionic Liquids and Deep Eutectic Solvents: A New Generation of Sorbents2017Ingår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 10, nr 2, s. 324-352Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    High cost and high energy penalty for carbon dioxide (CO2) uptake from flue gases are important obstacles in large-scale industrial applications, and developing efficient technology for CO2 capture from technic and economic points is crucial. Ionic liquids (ILs) show the potential for CO2 separation due to their inherent advantages and have been proposed as alternatives in order to overcome the drawbacks of conventional sorbents. Chemical modification of ILs to improve their performance in CO2 absorption has received more attention. Deep eutectic solvents (DESs) as a new generation of ILs are considered as more economical alternatives to cope with the deficiencies of high cost and high viscosity of conventional ILs. This review discusses the potential of the functionalized ILs and DESs as CO2 sorbents. Incorporation of CO2-philic functional groups like amine in cation and/or anion moiety of ILs can be promoted their absorption capacity. In general, the functionalization of anion part of ILs is more effective than cation part. DESs represent favourable solvent properties and are capable of capturing CO2, but the research work is scarce and undeveloped compared to the studies conducted on ILs. It is possible to develop novel DESs with promising absorption capacity. However, more investigation needs to be carried out on the mechanism of CO2 sorption of DESs to clarify how these novel sorbents can be adjusted and fine-tuned to best tailored as optimized media for CO2 capture.

  • 31.
    Yuan, Shengjuan
    et al.
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Yang, Zhuhong
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Chen, Yifeng
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Sun, Yunhao
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    CO2 absorption in mixed aqueous solution of MDEA and cholinium glycinate2017Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 31, nr 7, s. 7325-7333Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A new mixed solvent system that consists of cholinium glycinate ([Cho][Gly]) and aqueous N-methyldiethanolamine (MDEA) solution was developed in this work to serve as CO2 absorbent. The equilibrium absorption was carried out to investigate the effect of solution composition, pressure and temperature on CO2 absorption performance. The effect of CO2 absorption on the viscosity of the aqueous solutions was studied, and the regeneration efficiency of the aqueous solutions was also investigated. The results showed that the CO2 absorption loading decreased with increasing [Cho][Gly] concentration and temperature, and the absorption loading strongly depended on CO2 partial pressure. The reactivity of MDEA was significantly enhanced with the addition of [Cho][Gly]. The aqueous solution with (10 wt % [Cho][Gly] + 20 wt % MDEA) showed an optimal CO2 absorption and high regeneration efficiency. Furthermore, the CO2 absorption mechanism in the aqueous [Cho][Gly]-MDEA solution was explored by 13C Nuclear Magnetic Resonance (NMR), which indicated that the CO2 absorption in the aqueous [Cho][Gly]-MDEA solution was zwitterion mechanism.

  • 32.
    Zhang, Guanru
    et al.
    School of Earth Sciences, Zhejiang University, Hangzhou .
    Lu, Peng
    Department of Geological Sciences, Indiana University, Bloomington, IN .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Zhu, Chen
    School of Earth Sciences, Zhejiang University, Hangzhou .
    CO2 Plume Migration and Fate at Sleipner, Norway: Calibration of Numerical Models, Uncertainty Analysis, and Reactive Transport Modelling of CO2 Trapping to 10,000 Years2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 114, s. 2880-2895Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Sleipner Project in Norway is the world's first industrial-scale geological carbon dioxide storage project. Time-lapse seismic monitoring data have been collected, tracing CO2 plume development from 1996 to 2010. Therefore, the Sleipner Project provides a somewhat unique opportunity to simulate the dynamics of CO2 in a real geological system. The purpose of this study is to simulate CO2 plume migration dynamics and assess the impact of uncertain factors on short and long term migration and fate of CO2 for the uppermost layer (Layer 9) of the Utsira Sand.

    First, we applied a multi-phase compositional simulator to the Sleipner Benchmark model for Layer 9 and calibrated our model against the time-lapsed seismic monitoring data at the site from 1999 to 2008. By adjusting lateral permeability anisotropy, CH4 in the CO2 stream, and reservoir temperature, approximate match with the observed plume was achieved. Model-predicted gas saturation, thickness of the CO2 accumulation, and CO2 solubility in brine (none of them used as calibration metrics) were all comparable with interpretations of the seismic data in the literature.

    Second, hundreds of simulations of parameter sensitivity (pressure, temperature, feeders, spill rates, relative permeability curves, and CH4 content) were conducted for the plume migration, based on the calibrated model. The results showed that simulated plume extents are sensitive to permeability anisotropy, temperature, and CH4 content, but not sensitive to the other parameters. However, adjusting a single parameter within the reported range of values in the literature would not reproduce the north-south trending CO2 plume; it took a combination of permeability, CH4, and temperature adjustments to match simulated CO2 plume with seismic monitoring data. Although there is a range of uncertain parameters, the predicted fate of CO2 fell within a narrow band, ∼ 93±2% structural trapping and ∼ 7±2% solubility trapping. The calibrated model is not unique. Many combinations of permeability anisotropy, temperature, and CH4 would produce similar matches. Other possibilities that would have improved the development of an N–S elongated CO2 plume, such as a slight tilting of the surface of Utsira top to the south, were not experimented in this study, but are worthy of exploration for future studies.

    Finally, we used coupled reactive mass transport model to investigate the effects of rate laws and regional groundwater flow on long-term CO2 fate in Layer 9. The mineral composition and brine chemistry for the Utsira sand were adopted from the literature, and we modelled 100 year injection and continued water-rock interaction to 10,000 years. The results indicated that: (1) The predicted fraction of CO2 mineral trapping when using the linear rate law for feldspar dissolution is twice as much as when using the non-linear rate law. (2) Mineral trapping is more significant when regional groundwater flow is taken into consideration. Under the influence of regional groundwater flow, the replenishment of fresh brine from upstream continuously dissolves CO2 at the tail of CO2 plume, generating a larger acidified area where mineral trapping takes place. In a Sleipner like aquifer, the upstream replenishment of groundwater results in ∼ 22% mineral trapping at year 10,000, compared to the ∼ 4% when the effects of regional groundwater are ignored.

  • 33.
    Wu, Nanhua
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Xie, Wenlong
    China Petroleum Chemicals Kunshan Company.
    Liu, Chang
    State Key Laboratory of Materials-Oriented and Chemical Engineering, Nanjing Tech University.
    Feng, Xin
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing .
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Confinement Phenomenon Effect on the CO2 Absorption Working Capacity in Ionic Liquids Immobilized into Porous Solid Supports2017Ingår i: Langmuir, ISSN 0743-7463, E-ISSN 1520-5827, Vol. 33, nr 42, s. 11719-11726Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this work, the CO2 absorption working capacity and solubility in the ionic liquids immobilized into porous solid materials (substrates) was studied both experimentally and theoretically. The CO2 absorption working capacity in the immobilized ionic liquids was measured experimentally. It was found that the CO2 absorption working capacity and solubility increased up to 10 times compared to that in the bulk ionic liquids when the film thickness is nearly 2.5 nm in the [HMIm][NTf2] immobilized into the P25. Meanwhile, a new model was proposed to describe the Gibbs free energy of CO2 in the immobilized ionic liquids, and both macro- and micro-analyses of the CO2 solubility in the confined ionic liquids were conducted. The theoretical investigations reveal that the substrate has a crucial effect on the gas solubility in the ionic liquid immobilized into the substrates, and the model performance was approved with the consideration of substrate effect.

  • 34.
    Ma, Chunyan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Sarmad, Shokat
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Materialvetenskap.
    Mikkola, Jyri-Pekka
    Technical Chemistry, Department of Chemistry, Chemical-Biological Centre, Umeå University.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Development of Low-Cost Deep Eutectic Solvents for CO2 Capture2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 3320-3325Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CO2 capture plays an important role to mitigate CO2 emissions. Deep eutectic solvents (DESs) as promising absorbents for CO2 separation have raised lots of attention. As a new class of ionic liquids (ILs), DESs maintain most of the favorite properties of ILs but avoid their economic and environmental problems. However, the viscosity of the synthesized DESs is relatively high, resulting in slow mass transfer rate (or slow sorption kinetics) and then may lead to a large equipment-size. The CO2 solubility in the DESs still needs to be improved. In our work, 35 DESs were prepared and screened in terms of their CO2 solubility and viscosity. Among them, 15 DESs with high CO2 solubility and low viscosity compared to the conventional ILs were chosen as the promising candidates. In addition, the effect of water as a co-solvent for the glycerol-based DES with relatively high viscosity was investigated, and two other DESs that demonstrated relatively high sorption capacity and low viscosity were chosen for functionalization to further improve their CO2 sorption capacity. The results showed that the viscosity decreased drastically from 716 to 20 mPa·s, while the CO2 solubility increased from 0.26 to 0.33 mol/kg DES by the addition of a small amount of water into the glycerol-based DES (BTMA/GLY (1:2)). The further increase of the amount of H2O decreased the CO2 solubility due to the low CO2 solubility in H2O. In addition, after functionalization of TPAC/ EA(1:4), the CO2 solubility increased from 1.4 to 3.2 mol/kg DES, which showed a better performance compared with the common ILs.

  • 35.
    Zetterholm, Jonas
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Sundelin, Bo
    SSAB EMEA Oxelösund , SSAB Special Steels Oxelösund.
    Martin, P.M.
    Siemens VAI Metals Technologies, United States.
    Wang, C.
    Department of Process Integration, Swerea MEFOS AB.
    Dynamic modelling for the hot blast stove2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 185, nr 2, s. 2142-2150Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    A large amount of energy is required in the production of steel where the preheating of blast in the hot blast stoves for iron-making is one of the most energy-intensive processes. To improve the energy efficiency of the steelmaking it is necessary to investigate how to improve the hot blast stove operation.In this work a mathematic model for evaluating the performance of the hot blast stove was developed using a finite difference approximation for the heat transfer inside the stove during operation. The developed model was calibrated and validated by using the process data from hot blast stove V26 at SSABs plant in Oxelösund, Sweden. The investigation shows a good agreement between the measured and modelled data.As a case study, the developed model was used to simulate the effect of a new concept of OxyFuel technique to hot blast stoves. The investigation shows that, by using this OxyFuel technique, it is possible to maintain the blast temperature while removing the usage of coke oven gas (COG). The saved COG can be used to replace some fossil fuel, such as oil and LPG.Furthermore, the effect of the cycle time on the single stove was studied. As expected, both the hot blast and flue gas temperatures are increased when increasing the cycle time. This shows that it is a good strategy for the hot blast stove to increase the blast temperature if the stove is currently not operated with the maximum allowed flue-gas temperature. 

  • 36.
    Ma, Chunyan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University.
    Liu, Chang
    College of Chemical Engineering, Nanjing Tech University, Nanjing .
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Evaluation and comparison of aqueous ChCl/Urea and other physical absorbents for biogas upgrading process2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 3631-3636Artikel i tidskrift (Refereegranskat)
    Abstract [en]

     Biogas has been considered as an alternative renewable energy, and CO2 removal from raw biogas (i.e. biogas upgrading) is needed for producing biomethane used as vehicle fuels or injected into the natural gas grid. Biogas upgrading using physical absorbents is a simple and efficient technology with low energy requirements for regeneration. In this work, the conceptual process for biogas upgrading using 4 kinds of physical solvents, i.e. water, dimethyl ether of polyethylene glycol (DEPG), propylene carbonate (PC) and aqueous choline chloride (ChCl) /urea (AQDES) was developed and simulated with Aspen Plus. The energy utilization, the amount of recirculated solvent and the diameters of absorber and desorber were analyzed based on equilibrium approach. After that, the rate-based simulation was established to evaluate the specific cost of the process using different solvents. Based on equilibrium approach the comparison between the solvents in respect to the energy utilization for biogas upgrading using different solvents shows the following order: DEPG > water > AQDES > PC, whereas the amount of recirculated solvent and the diameters of absorber and desorber follow another order: water > DEPG > AQDES > PC. The rate-based results show that the process using PC has the lowest total specific cost, followed by AQDES, water and DEPG.

  • 37.
    Yuan, Shengjuan
    et al.
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Chen, Yifeng
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Yang, Zhuhong
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Experimental study of CO2 absorption in aqueous cholinium-based ionic liquids2017Ingår i: Fluid Phase Equilibria, ISSN 0378-3812, E-ISSN 1879-0224, Vol. 445, s. 14-24Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    CO2 removal (or separation) is the key step for biogas upgrading. This research aims to investigate aqueous solutions of amino acid ionic liquids to achieve effective CO2 separation. In this work, three cholinium-based amino acid ionic liquids ([Cho][AA]s) (i.e. cholinium glycinate ([Cho][Gly]), cholinium alaninate ([Cho][Ala]) and cholinium prolinate ([Cho][Pro])) were synthesized and characterized. The effect of water on the viscosity, CO2 absorption loading (m and α) and apparent absorption rate constant was systematically studied. The CO2 absorption mechanism in the aqueous solution of [Cho][Gly] was explored by 13C Nuclear Magnetic Resonance (NMR). The results demonstrate that the absorption loading (m) and viscosity increase with increasing IL concentration, while the apparent absorption rate constant decreases. The absorption loading decreased with increasing temperature. The CO2 absorption mechanism in the aqueous [Cho][Gly] solution started with the chemical reaction to form carbamate at low absorption loading (α), and followed by the hydrolysis of carbamate and CO2 hydration reaction at high absorption loading (α). Moreover, the aqueous solution with 5 wt % [Cho][Gly] showed the highest regeneration efficiency, and the absorption and regeneration performance of the aqueous solution of [Cho][Gly] was compared with commercial CO2 absorbents with promising results.

  • 38.
    Wu, Nanhua
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    An, Rong
    Herbert Gleiter Institute of Nanoscience, Nanjing University of Science & Technology.
    Liu, Chang
    College of Chemical Engineering, Nanjing Tech University, Nanjing .
    Lu, Xiaohua
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Generalized Gibbs free energy of confined nanoparticles2017Ingår i: AIChE Journal, ISSN 0001-1541, E-ISSN 1547-5905, Vol. 63, nr 10, s. 4595-4603Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The nanoparticles generally show abnormal properties compared to those in the bulk phase, and they exhibit significant potential in various applications such as catalysis and energy conversion. However, the theoretical work for describing the properties of nanoparticles is limited with poor prediction capacity. In this work, the Gibbs free energy was studied, from both macroscope and microscope, predictive models were proposed to study the thermodynamic properties of nanoparticles with a generalized description of the Gibbs free energy considering the effects of surface-energy and the substrate contacted. The proposed model from the microscope was based on the corresponding states theory to describe the effect of the substrate on the Gibbs free energy of nanoparticles, in which the molecular parameter with a generalized constant was obtained from the melting point of metals due to sufficient experimental information. The comparison with the new measured experimental results proves the reliability of the model prediction

  • 39.
    Chen, Jingjing
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University.
    Wu, Jiajun
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing .
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Wang, Changsong
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing .
    Mechanism of waste-heat recovery from slurry by scraped-surface heat exchanger2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 207, s. 146-155Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Waste-heat recovery from discharged slurries can improve the net raw biogas production in the bio-methane process in order to meet the demand for a next-generation of anaerobic digestion. In this study, a numerical model of a scraped-surface heat exchanger was proposed with the consideration of the complete and precise rheological behaviour of the slurry of animal manure for the first time for achieving highly efficient waste-heat recovery. The rheological model results were verified with new experimental data measured in this work. Subsequently, the convective heat-transfer coefficient of the scraped-surface heat exchanger was calculated numerically with the proposed numerical model, and the performance was determined. Then, the contributions of waste-heat recovery from the slurry to the biogas production using a general shell-and-tube heat exchanger and the scraped-surface heat exchanger were calculated quantitatively and compared. For the case of scraped-surface heat exchanger, the increase of net raw biogas production can be up to 8.53%, which indicates that there is a great potential to increase the net raw biogas production in the bio-methane process using a scraped-surface heat exchanger with low-cost equipment and a compactible structure.

  • 40.
    Chen, Jingjing
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Wang, Changsong
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing .
    Mechanism Study of Heat Transfer Enhancement Using Twisted Hexagonal Tube with Slurry from Biogas Plant2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 142, s. 880-885Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Waste-heat recovery from discharged slurries is important to improve the biogas production efficiency but still remains challenge duo to the special properties of slurries in anaerobic digestion process. In this work, numerical study was carried out to investigate the flow field, and heat transfer performance of slurry from biogas plant in the twisted hexagonal and other twisted tubes was simulated with computer fluid dynamic (CFD) for the first time. The numerical method was validated with experimental data from the literature. The heat transfer performance and flow resistance of twisted hexagon tube were calculated and compared with other types of twisted tubes. The enhancement factor of the twisted hexagonal tube reached to 2 and kept optimum at turbulence flow region compared to the twisted tubes with square and elliptical cross section. Meanwhile, the mechanism of heat transfer enhancement with different twisted tubes was further studied, and the optimal field synergy and minimum local circulation flow near the wall are the main reasons for the high performance and low flow resistance of the twisted hexagonal tube.

  • 41.
    Chen, Jingjing
    et al.
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Ma, Chunyan
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Ji, Xiaoyan
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing Tech University, Nanjing .
    Wang, Changsong
    State Key Laboratory of Material-Oriented Chemical Engineering, Nanjing Tech University, Nanjing .
    Mechanism Study of Waste Heat Recovery from Slurry by Surface Scraped Heat Exchanger2017Ingår i: Energy Procedia, ISSN 1876-6102, E-ISSN 1876-6102, Vol. 105, s. 1109-1115Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Waste-heat recovery from discharged slurries can improve the net raw biogas production in bio-methane process in order to meet the demand of a new generation of anaerobic digestion. In order to achieve a high efficient waste-heat recovery, in this work, a mathematical model of waste-heat recovery process with surface scraped heat exchanger (SSHE) was proposed with the consideration of the shear rate and temperature-dependent rheological behaviour. The convective heat transfer performance of SSHE was calculated numerically where slurry was considered. The contribution of waste heat recovery from the slurry to biogas production by SSHE and general shell-and-tube heat exchanger (STHE) were firstly calculated quantitatively, and the increase of net raw biogas production could be over 13.5% by SSHE with need of heat exchange area less than a quarter of STHE's, which showed a great potential to increase the net raw biogas production in bio-methane process with low equipment investments and more compactible structure.

  • 42.
    Ma, Chunyan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. College of Chemical Engineering, Nanjing Tech University, Nanjing.
    Xie, Yujiao
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Liu, Chang
    College of Chemical Engineering, Nanjing Tech University, Nanjing .
    Lu, Xiaohua
    College of Chemical Engineering, Nanjing Tech University, Nanjing .
    Modeling, simulation and evaluation of biogas upgrading using aqueous choline chloride/urea2017Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 229, nr 1, s. 1269-1283Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biogas has been considered as an alternative renewable energy, and raw biogas needs to be upgraded in order to be used as vehicle fuels or injected into the natural gas grid. In this work, the conceptual process for biogas upgrading using aqueous choline chloride (ChCl)/urea (1:2 on a molar basis) was developed, simulated and evaluated based on the commercialized software Aspen Plus. Reliable thermophysical properties and phase equilibria are prerequisite for carrying out process simulation. In order to carry out the process simulation, the thermophysical properties of ChCl/Urea (1:2) and its aqueous solutions as well as the phase equilibria of gas-ChCl/Urea (1:2), ChCl/Urea (1:2)-H2O and gas-ChCl/Urea (1:2)-H2O were surveyed and evaluated. After evaluation, the consistent experimental data of these thermophysical properties were fitted to the models embedded in Aspen Plus. The properties needed but without available experimental results were predicted theoretically. The Non-Random Two-Liquid model and the Redlich-Kwong equation (NRTL-RK) model were used to describe the phase equilibria. The equilibrium approach was used for process simulation. Sensitivity analysis was conducted to determine the reasonable operating parameters. With a set of reasonable operating conditions, the effects of ChCl/Urea (1:2) content on the total energy utilization, the diameters and pressure drops of absorber and desorber as well as the environmental assessment of the process were studied. The simulation results showed that, with the addition of ChCl/Urea (1:2), the total energy utilization decreased by 16% compared to the process with pure water, and the diameters of both absorber and desorber decreased with increasing content of ChCl/Urea (1:2). The process using aqueous ChCl/Urea (1:2) was more environmentally benign than that with pure water. Therefore, aqueous ChCl/Urea (1:2) is a promising solvent for biogas upgrading.

  • 43.
    Ma, Chunyan
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. College of Chemical Engineering, Nanjing Tech University.
    Guo, Yanhua
    College of Chemical Engineering, Nanjing Tech University.
    Li, Dongxue
    College of Chemical Engineering, Nanjing Tech University.
    Zong, Jianpeng
    College of Chemical Engineering, Nanjing Tech University.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Liu, Chang
    College of Chemical Engineering, Nanjing Tech University.
    Molar enthalpy of mixing and refractive indices of choline chloride-based deep eutectic solvents with water2017Ingår i: Journal of Chemical Thermodynamics, ISSN 0021-9614, E-ISSN 1096-3626, Vol. 105, s. 30-36Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The molar enthalpies of mixing were measured for binary systems of choline chloride-based deep eutectic solvents (glycerol, ethylene glycol and malonic acid) with water at 298.15 K and 308.15 K, and atmospheric pressure with an isothermal calorimeter. Refractive indices were also measured at 303.15 K and atmospheric pressure. The binary mixtures of {chcl/glycerol (1:2) + water, chcl/ethylene glycol (1:2) + water} showed exothermic behaviour over the entire range of composition, while the binary mixture of {chcl/malonic acid (1:1) + water} showed endothermic behaviour at first and then changed to be exothermic with the increasing content of chcl/malonic acid (1:1). Experimental refractive indices were fitted with the Redlich–Kister equation, and experimental molar enthalpies of mixing were correlated with the Redlich–Kister equation and the non-random two-liquid (NRTL) model. The NRTL model with the fitted parameters was used to predict the vapour pressures of these three mixtures. For mixtures of {chcl/glycerol (1:2) + water} and {chcl/ethylene glycol (1:2) + water}, the predicted vapour pressures agreed well with the experimental reults from the literature. While for mixture of {chcl/malonic acid (1:1)+water}, the predicted vapour pressures showed deviation at the high concentration of chcl/malonic acid (1:1), and this was probably because of the complex molecular interaction between chcl/malonic acid (1:1) and water

  • 44.
    Tan, Zhongxin
    et al.
    College of Resources and Environment, Huazhong Agricultural University.
    Lin, Carol S.K.
    School of Energy and Environment, City University of Hong Kong,Tat Chee Avenue, Kowloon, Hong Kong.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Rainey, Thomas J.
    School of Chemistry, Physics and Mechanical Engineering, Science and Engineering Faculty, Queensland University of Technology.
    Returning biochar to fields: A review2017Ingår i: Agriculture, Ecosystems & Environment. Applied Soil Ecology, ISSN 0929-1393, E-ISSN 1873-0272, Vol. 116, s. 1-11Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Biochar generated from thermochemical conversion of biomass reduces greenhouse gas emissions and is useful for improving ecological systems in agriculture. However, certain biochars function well in improving soil, and other biochars do not. Why? Because it is not clear how to prepare the best biochar for soil. There is a disconnect between biochar preparation and returning the biochar to the soil. To elucidate this relationship, this paper reviews (i) technologies for preparing biochar, (ii) how preparation conditions affect biochar properties, and (iii) the effects on soil physical and chemical properties. In addition to reducing greenhouse gas emissions, biochar improves the physicochemical and microbial properties of soil and absorbs poisonous and pernicious substances. Therefore, as biochar is produced by pyrolysis, optimizing processing conditions to improve its properties for agricultural use is a key issue explored in this article.

  • 45.
    Sarmad, Shokat
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Xie, Yujiao
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Mikkola, Jyri-Pekka
    Technical Chemistry, Department of Chemistry, Chemical-Biological Centre, Umeå University.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Screening of Deep Eutectic Solvents (DESs) as green CO2 sorbents: from solubility to viscosity2017Ingår i: New Journal of Chemistry, ISSN 1144-0546, E-ISSN 1369-9261, Vol. 41, nr 1, s. 290-301Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Deep eutectic solvents (DESs) as ionic liquid (IL) analogues show great potential for CO2 capture. They exhibit favorable solvent properties and are considered to be economical alternatives to conventional ILs. In this study, we prepare 35 DESs and screen them in terms of their CO2 solubility and viscosity, both crucial factors to be considered when designing efficient CO2 sorbents. The influence of salt and HBD type and structure, as well their molar ratio on the CO2 solubility and viscosity of the DESs is investigated. The viscosity and CO2 solubility of the DESs are compared with those of other DESs and conventional ILs. 15 DESs, which exhibit comparable CO2 absorption capacity to choline chloride-urea DESs, glycerol DESs and fluorinated ILs, are chosen as the promising ones. The viscosities of the selected DESs are below 200 mPa s and are lower than those of choline chloride-based DESs. Since the viscosity of the DESs is relatively high, on a par with those of conventional ILs, the effect of water as a co-solvent is investigated in order to decrease the viscosity. The addition of water to the glycerol-based DESs improves the kinetics of absorption by decreasing the viscosity, thus increasing the CO2 absorption capacity. Dry or aqueous DESs that demonstrate a high sorption capacity and low viscosity are chosen for additional analysis and characterization, and further functionalization will be carried out in the future to improve their sorption capacityy

  • 46.
    Xie, Yujiao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Dong, Haifeng
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences.
    Zhang, Soujiang
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences.
    Lu, Xuaihua
    Beijing Key Laboratory of Ionic Liquids Clean Process, State Key Laboratory of Multiphase Complex System, Institute of Process Engineering, Chinese Academy of Sciences.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Solubilities of CO2, CH4, H2, CO and N2 in choline chloride/urea2017Ingår i: Green Energy & Environment, ISSN 2468-0257, Vol. 1, nr 3, s. 195-200Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Solubilities of CO2, CH4, H2, CO and N2 in choline chloride/urea (ChCl/Urea) were investigated at temperatures ranging from 308.2 to 328.2 K and pressures ranging from 0.6 to 4.6 MPa. The results show that the solubilities of gases increase with increasing pressure and decreasing temperature. The solubility of CO2 is higher than that of CH4, H2, CO and N2, which indicates that ChCl/Urea may be used as a potential solvent for CO2 capture from the gas mixture. Solubility of CO2 in ChCl/Urea was fitted by Non-Random Two-Liquid and Redlich–Kwong (NRTL-RK) model, and solubility of CH4, H2, CO or N2 in ChCl/Urea was fitted by Henry's Law. The standard enthalpy, standard Gibbs energy and standard entropy of gases were calculated. Additionally, the CO2/CH4 selectivities in water, dry ChCl/Urea and aqueous ChCl/Urea were further discussed.

  • 47.
    Xie, Wenlong
    et al.
    Department of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Fan, Tengteng
    Department of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Feng, Xin
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing University of Chemical Technology, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    CO2 uptake behavior of supported tetraethylenepentamine sorbents2016Ingår i: Energy & Fuels, ISSN 0887-0624, E-ISSN 1520-5029, Vol. 30, nr 6, s. 5083-5091Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Supported tetraethylenepentamine (TEPA) sorbents have been proposed as an attractive alternative for postcombustion carbon capture. To promote the application of these sorbents, in this work, a systematic investigation of CO2 absorption behavior on five TEPA-immobilized sorbents was conducted, in which the effects of TEPA loading, supports, and temperatures on both CO2 absorption working capacity and kinetics were studied. Poly(methyl methacrylate) (PMMA)-TEPA is the best among the studied sorbents. The optimal temperature for PMMA-TEPA was 25 deg lower compared to other sorbents studied in this work, and the maximum CO2 capacity was 0.17 g/g-sorbent. This is the highest value reported to date for PMMA-TEPA sorbents, and one of the high values that have been reported for TEPA-immobilized sorbents. In addition, the working capacity of PMMA-TEPA after six cycles of regeneration was 0.16 g/g-sorbent (i.e., with only 6% decrease). Therefore, PMMA is promising to be used as supporting material for TEPA in CO2 capture. The kinetics analysis with both the Avrami’s fractional-order kinetic model and the mass-transfer model on the basis of nonequilibrium thermodynamics was further conducted and discussed. Besides, it was also found that the CO2 absorption kinetics and capacity were affected by both the pore structure and the surface chemistry of the support.

  • 48.
    Fan, Tengteng
    et al.
    College of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Xie, Wenlong
    College of Chemistry and Chemical Engineering, State Key Laboratory of Materials-College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Liu, Cheng
    College of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Feng, Xie
    College of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Lu, Xiaohua
    College of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    CO2/N2 separation using supported ionic liquid membranes with green and cost-effective [Choline][Pro]/PEG200 mixtures2016Ingår i: Chinese Journal of Chemical Engineering, ISSN 1004-9541, E-ISSN 2210-321X, Vol. 24, nr 11, s. 1513-1521Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The high price and toxicity of ionic liquids (ILs) have limited the design and application of supported ionic liquid membranes (SILMs) for CO2 separation in both academic and industrial fields. In this work, [Choline][Pro]/polyethylene glycol 200 (PEG200) mixtures were selected to prepare novel SILMs because of their green and cost-effective characterization, and the CO2/N2 separation with the prepared SILMs was investigated experimentally at temperatures from 308.15 to 343.15 K. The temperature effect on the permeability, solubility and diffusivity of CO2 was modeled with the Arrhenius equation. A competitive performance of the prepared SILMs was observed with high CO2 permeability ranged in 343.3-1798.6 barrer and high CO2/N2 selectivity from 7.9 to 34.8. It was also found that the CO2 permeability increased 3 times by decreasing the viscosity of liquids from 370 to 38 mPa·s. In addition, the inherent mechanism behind the significant permeability enhancement was revealed based on the diffusion-reaction theory, i.e. with the addition of PEG200, the overall resistance was substantially decreased and the SILMs process was switched from diffusion-control to reaction-control. 

  • 49.
    Xie, Yujiao
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Ma, Chunyan
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Lu, Xiaohua
    Key Laboratory of Material and Chemical Engineering, Nanjing University of Technology.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Evaluation of imidazolium-based ionic liquids for biogas upgrading2016Ingår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 175, s. 69-81Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The conceptual processes for biogas upgrading using three imidazolium-based ionic liquids ([hmim][Tf2N], [bmim][Tf2N] and [bmim][PF6]) were simulated in Aspen Plus to study the effect of properties of ionic liquids (ILs) on the process performance. To conduct the process simulation, each IL was input into Aspen Plus as a pseudo component, their critical properties were estimated by group contribution method, and their thermo-physical properties were correlated from the available experimental data by semi-empirical equations. The gas solubility in ILs was modeled with the non-random two-liquid model and Redlich–Kwong equation of state. Among the studied ILs, the simulation results show that the amount of recirculated solvents and the total energy consumption for upgrading process using ILs follow: [bmim][Tf2N] < [bmim][PF6] < [hmim][Tf2N]. The effects of density and viscosity of ILs on pressure drop and diameter of the absorber as well as the effects of operational pressures and temperatures on the process efficiency were investigated. It is found that the energy consumption increases with increasing pressure and temperature in the absorber and decreases with increasing pressure in the first flash tank. The ILs-based technology was further compared with water scrubbing and aqueous choline chloride/urea scrubbing, and the comparison shows that the total energy consumptions follow: 50%ChCl/Urea-water < [bmim][Tf2N] scrubbing < water scrubbing

  • 50.
    Xie, Wenlong
    et al.
    Department of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Ji, Xiaoyan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Feng, Xin
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Nanjing University of Chemical Technology, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, Department of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology, College of Chemistry and Chemical Engineering, Nanjing University of Technology, Department of Chemistry and Chemical Engineering, State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Mass Transfer Rate Enhancement for CO2 Separation by Ionic Liquids: Effect of Film Thickness2016Ingår i: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 55, nr 1, s. 366-372Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Ionic liquids (ILs) are promising in CO2 separation, while the film thickness is particularly critical for gas transport in these viscous and expensive liquids. In this work, the influence of IL-film thickness on CO2 absorption/desorption of two different IL immobilized sorbents was investigated, in which the results from the thermogravimetric analyzer were further used to estimate the scale of IL-film thickness. It is found that the IL-film in nanoscale is a prerequisite for efficient CO2 absorption/desorption; the equilibrium time can be 10-times different, and the rate constant can be 100-times different for microscale and nanoscale IL-films. This is the first time to quantitatively reveal the influence of IL-film thickness and find out its scale for a significant rate enhancement in the CO2 absorption/desorption by IL immobilized sorbents

123 1 - 50 av 137
RefereraExporteraLänk till träfflistan
Permanent länk
Referera
Referensformat
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annat format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annat språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf