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  • 1.
    Agarwal, Parminder
    et al.
    Michigan State University.
    Yu, Qiuyue
    Michigan State University.
    Harant, Adam
    Michigan State University.
    Berglund, Kris
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Synthesis and characterization of polymaleimide2003In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 42, no 13, p. 2881-2884Article in journal (Refereed)
    Abstract [en]

    Simplified syntheses of polymaleimide employing anionic polymerization (from the melt and from solution) and metal compound-alcohol initiators such as PbO, SnO, tin bis(2-ethyl hexanoate) in the presence of tert-butyl benzyl alcohol are presented. The resulting polymers contain a combination of C-N- and C-C-connected monomers. Preliminary structures of the polymers were determined using NMR spectroscopy. The ratio of C-N- and C-C-connected monomers was determined, and the percentage of C-N-connected monomer units was found to vary from 40 to 80%, with the higher percentage resulting from anionic polymerization. The molecular weights of the polymers, as determined by gel permeation chromatography (GPC) with aqueous mobile phase and sodium polyacrylates standards, ranged between 1100 and 4200 for anionic polymerization and were about 11 500 for metal oxide-alcohol initiated polymerization. Solution-phase properties of the polymaleimides were evaluated by calcium chelation and precipitation inhibition studies. On the basis of the measured properties of these polymers, they are proposed as biodegradable, low-impact detergent additives to substitute currently used compounds.

  • 2.
    Carabante, Ivan
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Mouzon, Johanne
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Kumpiene, Jurate
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Geosciences and Environmental Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Fredriksson, Andreas
    Mining Technology R and D, LKAB Kiruna Mine.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Reutilization of porous sintered hematite bodies as effective adsorbents for arsenic(V) removal from water2014In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 32, p. 12689-12696Article in journal (Refereed)
    Abstract [en]

    A method was developed to enhance the arsenic adsorption capacity of porous bodies of sintered hematite. The method comprised the formation of a coating of 1 wt % iron oxide nanoparticles on the raw material. The nanoparticles showed two distinct habits: spherical habit, likely ferrihydrite, and acicular habit, likely goethite and/or akaganéite. The specific surface area of the hematite raw material increased from 0.5 to 3.75 m2/g, and the adsorption capacity increased from negligible to 0.65 mg of [As]/g as calculated from equilibrium and breakthrough adsorption data. Equilibrium adsorption data of arsenate on the adsorbent from a solution at pH 5 followed the Langmuir model, while breakthrough adsorption data for a 500 μg/L arsenate solution at pH 5 followed the Thomas model. The adsorbed arsenic could be desorbed using distilled water at pH 12. These results show the potential for the reutilization of waste products comprising coarse hematite bodies as adsorbents.

  • 3.
    Gao, Huihui
    et al.
    School of Information Science and Technology, Beijing University of Chemical Technology, Beijing.
    Gajjar, Shriram
    Department of Chemical Engineering, University of California, Davis.
    Kulahci, Murat
    Luleå University of Technology, Department of Business Administration, Technology and Social Sciences, Business Administration and Industrial Engineering.
    Zhu, Qunxiong
    School of Information Science and Technology, Beijing University of Chemical Technology, Beijing.
    Palazoglu, Ahmet
    Department of Chemical Engineering, University of California, Davis.
    Process Knowledge Discovery Using Sparse Principal Component Analysis2016In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 55, no 46, p. 12046-12059Article in journal (Refereed)
    Abstract [en]

    As the goals of ensuring process safety and energy efficiency become ever more challenging, engineers increasingly rely on data collected from such processes for informed decision making. During recent decades, extracting and interpreting valuable process information from large historical data sets have been an active area of research. Among the methods used, principal component analysis (PCA) is a well-established technique that allows for dimensionality reduction for large data sets by finding new uncorrelated variables, namely principal components (PCs). However, it is difficult to interpret the derived PCs, as each PC is a linear combination of all of the original variables and the loadings are typically nonzero. Sparse principal component analysis (SPCA) is a relatively recent technique proposed for producing PCs with sparse loadings via the variance–sparsity trade-off. We propose a forward SPCA approach that helps uncover the underlying process knowledge regarding variable relations. This approach systematically determines the optimal sparse loadings for each sparse PC while improving interpretability and minimizing information loss. The salient features of the proposed approach are demonstrated through the Tennessee Eastman process simulation. The results indicate how knowledge and process insight can be discovered through a systematic analysis of sparse loadings.

  • 4.
    He, Hanbing
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Yao, Wenjun
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Yang, Changsong
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Feng, Xin
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, College of Chemistry and Chemical Engineering, Nanjing University of Technology.
    Morphology-controlled synthesis of sodium hexa-titanate nanowhiskers by changing evaporation rate of NaCl-KCl molten salts2013In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 43, p. 15034-15040Article in journal (Refereed)
    Abstract [en]

    Na2Ti6O13 nanowhiskers with controllable morphologies were prepared via a simple molten salt evaporation method using a small quantity of NaCl-KCl as molten salt. The synthesized products were characterized by X-ray diffraction, field emission scanning electron microscope, and transmission electron microscope. The optimal growth dynamic conditions for synthesis of Na2Ti6O13 nanowhiskers were also studied and discussed. According to thermogravimetry-differential scanning calorimetry analysis, the calcination process was designed to include two stages, lower temperature for reaction and higher temperature for evaporation of molten salt. Nanowhiskers and nanorods with different diameters can be obtained under different evaporation conditions. By comparing residual amounts of NaCl-KCl on product surfaces calculated by determined kinetic equation and experimental results only using NaCl as molten salt, it was revealed that the molten salt evaporation rates could play an important role on the morphologies of Na2Ti6O13. A formation mechanism was provided based on nucleation and growth model and an oriented aggregation process to understand different morphologies of Na2Ti 6O13. This simple molten salt evaporation method would be suitable for large scale synthesis

  • 5.
    Hodge, David
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Stoklosa, Ryan J.
    Department of Chemical Engineering and Materials Science, Michigan State University, East Lansing.
    Extraction, recovery, and characterization of hardwood and grass hemicelluloses for integration into biorefining processes2012In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 51, no 34, p. 11045-11053Article in journal (Refereed)
    Abstract [en]

    For this work, four hardwoods (silver birch, sugar maple, a hybrid poplar, and a hybrid aspen) and one cultivar of switchgrass were treated with increasing levels of NaOH. The recovered cell wall biopolymers were characterized based on total extraction, precipitation using ethanol or acidification, xylan content, and molar mass of the recovered precipitates. The extractability of cell wall polymers was clearly shown to be a function of the biomass type with more than 50% of the cell walls of switchgrass solubilized by alkali while only up to 20% of the maple was solubilized under comparable conditions. Precipitation with ethanol resulted in high recovery yields of hemicelluloses from the original biomass for silver birch and switchgrass, and most notably, the birch precipitates contained double the hemicellulose content of the precipitates from other feedstock alkali extracts (80% versus 30-50%). The molar masses of the recovered hemicellulosic polysaccharides were characterized using size exclusion chromatography (SEC) and an assay to quantify polysaccharide reducing ends. SEC analysis showed that the biopolymers exhibited a strong tendency to self-associate during elution and that this aggregation could be eliminated through sonication. The reducing end method showed an increase in the number-average degree of polymerization toward an asymptotic maximum with increasing extraction pH, and this value was significantly increased by bleaching the precipitate to remove interference by nonpolysaccharides

  • 6.
    Huang, Wenjuan
    et al.
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Ji, Yuanhui
    Yang, Zhuhong
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Feng, Xin
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Zhu, Yinhua
    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.
    Mineralization of Trace Nitro/Chloro/Methyl/Amino-Aromatic Contaminants in Wastewaters by Advanced Oxidation Processes2010In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 49, no 13, p. 6243-6249Article in journal (Refereed)
    Abstract [en]

    It has great significance to investigate the degradation of aromatic contaminants as they are highly carcinogenic and nondegradable pollutants in drinking water. In this paper, the mineralization orders of the representative nitro/chloro/methyl/amino-aromatic contaminants with oxidants (OH, H2O2, O-, O2,O3) in advanced oxidation processes (AOPs) are investigated based on the calculated standard molar Gibbs free energy changes of reaction (ΔrGm0) and the results are consistent with those from previous experimental results, electrophilic substitution orientation rules of the Hammett equation, and predicted results with a quantitative structure-activity relationship (QSAR). In addition, the quantitative function relationship between the degradation rate (r) of the aromatic contaminants and the thermodynamic driving force (ΔrGm0) is analyzed in order to investigate the degradation kinetics more rigorously.

  • 7. Ji, Xiaoyan
    et al.
    Adidharma, Hertanto
    University of Wyoming.
    Ion-based SAFT2 to represent aqueous single- and multiple-salt solutions at 298.15 K2006In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 45, p. 7719-7728Article in journal (Refereed)
    Abstract [en]

    SAFT2 with individual-ion parameters, referred to as ion-based SAFT2, is used to represent the properties of aqueous electrolyte solutions. A new set of parameters for 5 cations (Li+, Na+, K+, Ca2+, and Mg2+) and 6 anions (Cl-, Br-, I-, NO3-, SO42-,and HCO3-) is obtained from the fitting of the experimental mean ionic activity coefficients and liquid densities of 24 aqueous single-salt solutions at 298.15 K. The ion parameters are universal and transferable to different salts containing the same ion. Because of the peculiar segment energy of K+, a mixing rule with a binary interaction parameter for the segment energy describing the shortrange interactions between K+ and other cations is needed. The binary interaction parameter is derived from the osmotic coefficients of chloride solutions. The predictions of the osmotic coefficients, vapor pressures, and liquid densities of single- and multiple-salt solutions including seawater (brine) are found to agree with experimental data.

  • 8. Ji, Xiaoyan
    et al.
    Adidharma, Hertanto
    University of Wyoming.
    Ion-based statistical associating fluid theory (SAFT2) to represent aqueous single-salt solutions at temperatures and pressures up to 473.15 K and 1000 bar2007In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 46, no 13, p. 4667-4677Article in journal (Refereed)
    Abstract [en]

    Ion-based SAFT2 is used to represent the properties of aqueous single-salt solutions in the temperature, pressure, and concentration ranges of 298.15-473.15 K, 1.013-1000 bar, and 0-6 mol/kgH2O in ionic strength, respectively. The short-range interaction between cation and anion is needed to capture the effect of pressure on the properties of electrolyte solutions. A new set of parameters at 298.15 K for five cations (Li+, Na+, K+, Ca2+, Mg2+) and seven anions (Cl-, Br-, I-, NO3-, HCO3-, SO42-, CO32-) is obtained from the fitting of the experimental mean ionic activity coefficients and liquid densities of 26 aqueous single-salt solutions. An additional set of ion-specific coefficients used in the temperature-dependent parameter expressions for five cations (Li+, Na+, K+, Ca2+, Mg2+) and five anions (Cl-, Br-, HCO3-, SO42-, CO32-) is obtained from the fitting of the experimental mean ionic activity coefficients and liquid densities of 15 aqueous single-salt solutions at low pressures and temperatures up to 473.15 K. The activity coefficients, osmotic coefficients, water activities, densities, and vapor pressures of single-salt solutions at elevated temperatures and pressures are predicted without any adjustment.

  • 9. Ji, Xiaoyan
    et al.
    Feng, Xin
    Nanjing University of Chemical Technology.
    Lu, Xiaohua
    Nanjing University of Chemical Technology.
    Zhang, Luzheng
    Nanjing University of Chemical Technology.
    Wang, Yanru
    Nanjing University of Chemical Technology.
    Shi, Jun
    Nanjing University of Chemical Technology.
    A generalized method for the solid-liquid equilibrium stage and its application in process simulation2002In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 41, p. 2040-2046Article in journal (Refereed)
    Abstract [en]

    For the important need of simulations of the crystallization process in aqueous electrolyte solutions, a generalized method is proposed in this paper for predicting the solid-liquid equilibrium stage by identifying the number of phases and their identities automatically. The proposed method is also used to generate phase diagrams and crystallization paths and to provide an example of the software that can be used to design, simulate, and optimize the related process. Several cases are studied to demonstrate the capability of the proposed method for systems with hydrate, multi-ion, and complex salts.

  • 10. Ji, Xiaoyan
    et al.
    Tan, Sugata P.
    University of Wyoming.
    Adidharma, Hertanto
    University of Wyoming.
    Radosz, Maciej
    University of Wyoming.
    SAFT1-RPM approximation extended to phase equilibria and densities of CO2-H2O and CO2-H2O-NaCl systems2005In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 44, p. 8419-8427Article in journal (Refereed)
    Abstract [en]

    In SAFT1-RPM approximations of CO2-H2O and CO2-H2O-NaCl systems, relevant to oil recovery and CO2 sequestration, CO2 is modeled as a molecule with three association sites, two sites of type O and one site of type C. H2O is modeled as a molecule with four association sites, two sites of type O and two sites of type H. The salt is modeled as a molecule composed of two charged, but nonassociating, spherical segments, of which one represents the cation and one represents the anion. For the CO2-H2O system, only one type of cross-association is assigned, i.e., between the site of type O in CO2 and the site of type H in H2O. Using temperature-dependent parameters, SAFT1-RPM is found to represent the density and equilibrium data for the CO2-H2O system, including the minimum H2O concentration in the CO2-rich phase in the y-P diagram. For the CO2-H2O-NaCl system, an additional binary interaction constant is used, the same for both CO2-Na+ and CO2-Cl- pairs, which is needed to correct the short-range interactions. SAFT1-RPM is also found to represent the equilibrium and density data for the CO2-H2O-NaCl system.

  • 11. Ji, Xiaoyan
    et al.
    Tan, Sugata P.
    University of Wyoming.
    Adidharma, Hertanto
    University of Wyoming.
    Radosz, Maciej
    University of Wyoming.
    Statistical associating fluid theory coupled with restricted primitive model to represent aqueous strong electrolytes: multiple-salt solutions2005In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 44, p. 7584-7590Article in journal (Refereed)
    Abstract [en]

    Statistical associating fluid theory coupled with the restricted primitive model (SAFT1-RPM), previously proposed for representing single-salt solutions in water, is extended to multiple-salt solutions using a mixing rule for the hydrated diameter. A binary adjustable parameter in this mixing rule, for a pair of salts, is obtained from experimental osmotic coefficients of the corresponding ternary system. The ternary systems considered contain water and all pairs of NaCl, KCl, NaBr, and KBr. LiCl + NaCl and LiCl + KCl pairs are also correlated. The adjustable parameters are used to predict the density of the ternary systems with or without common ions, the solubility of two ternary systems, and the osmotic coefficient of a quaternary NaCl-KCl-LiCl-H2O solution.

  • 12.
    Ji, Yuanhui
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Yang, Zhuhong
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Ji, Xiaoyan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Feng, Xin
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Huang, Wenjuan
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Liu, Chang
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Li, Wei
    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.
    Thermodynamic analysis on the mineralization of trace organic contaminants with oxidants in advanced oxidation processes2009In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 48, no 23, p. 10728-10733Article in journal (Refereed)
    Abstract [en]

    There is a growing demand for the efficient treatment of organic polluted wastewaters by advanced oxidation processes (AOPs) which calls for the determination of the mineralization order of ease for the organic contaminants with oxidants. The mineralization abilities of organic contaminants in AOPs are investigated in this work. Photocatalytic experiments for three representative organic contaminants are carried out, and their corresponding reaction rates are determined experimentally. Meanwhile, molar Gibbs free energy changes Delta(r)G(m)degrees for the reactions of 31 organic contaminants (10 chlorinated hydrocarbons, four brominated hydrocarbons, I I aromatic hydrocarbons and their derivatives, three chloroacetic acid, and three chloroacetyl chloride) with oxidants of (OH)-O-center dot, H2O2, O-center dot(-), O-3, and O-2 are calculated, and the mineralization order of ease is determined theoretically on the basis of Delta(r)G(m)degrees. The agreement of the theoretical and experimental mineralization abilities for most of the organic contaminants investigated implies the reliability of the determination of the mineralization ability from the magnitude of Delta(r)G(m)degrees for the mineralization of trace organic contaminants. Results also show that for most of the organic contaminants studied, the mineralization abilities are (OH)-O-center dot > H2O2 > O-center dot(-) > O-3 > O-2, and the mineralization ability of the organic contaminants depends on not only the oxidants but also the structure and properties of the organic contaminants themselves, and the degradation reaction products.

  • 13.
    Kadhim, Ali
    et al.
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems. Department of Electrical Engineering, University of Kufa, Najaf, Iraq.
    Castaño Arranz, Miguel
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Birk, Wolfgang
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Signals and Systems.
    Automated Control Configuration Selection Considering System Uncertainties2017In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 56, no 12, p. 3347-3359Article in journal (Refereed)
    Abstract [en]

    This paper proposes an automated pairing approach for configuration selection of decentralized controllers which considers system uncertainties. Following the Relative Interaction Array (RIA) pairing rules, the optimal control configuration, i.e. the configuration that fits best the pairing rules, is obtained automatically by formulating the control configuration selection problem as an Assignment Problem (AP). In this AP, the associated costs related to each input-output pairing are given by the RIA coefficients. The Push-Pull algorithm is used to solve the AP for the nominal system and to obtain the set of costs for which the resulting configuration remains optimal, also called the perturbation set. The introduction of uncertainty bounds on the RIA-based costs enables the testing of the possible violation of the optimality conditions. Examples to illustrate the proposed approach for a 3×3 system and 4×4 gasifier plant are given.

  • 14.
    Leppäjärvi, Tiina
    et al.
    Department of Process and Environmental Engineering, University of Oulu.
    Malinen, Ilkka
    Department of Process and Environmental Engineering, University of Oulu.
    Korelskiy, Danil
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Chemical Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering.
    Tanskanen, Juha
    Oulu University.
    Maxwell-Stefan Modeling of Ethanol and Water Unary Pervaporation Through a High-silica MFI Zeolite Membrane2014In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 1, p. 323-332Article in journal (Refereed)
    Abstract [en]

    The pervaporative mass transfer of pure ethanol and water through a thin (0.5 mu m) supported high-silica MFI membrane was studied experimentally at 30-70 degrees C, and modeled on the basis of the Maxwell-Stefan formalism. The temperature dependency of adsorption was described with the temperature dependency of pure component saturated vapor pressure. Two scenarios of coverage dependency, i.e., coverage-dependent and coverage-independent Maxwell-Stefan diffusivity, were applied in the modeling of the mass transfer through the zeolite film. In addition, the mass-transfer resistance of the support layers was taken into account. The derived unary models provided good representations of ethanol and water pervaporation flux. The study illustrates that pure component steady-state pervaporation flux measurements at different conditions offer a feasible basis for determining diffusion coefficients. Basically, pure component adsorption isotherms and derived diffusivities can be used in the modeling of pervaporative mass transfer of mixtures using zeolite membranes

  • 15.
    Potapova, Elisaveta
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Carabante, Ivan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Holmgren, Allan
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hedlund, Jonas
    Studies of collector adsorption on iron oxides by in-situ ATR-FTIR spectroscopy2010In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 49, no 4, p. 1493-1502Article in journal (Refereed)
    Abstract [en]

    In this work, the adsorption of three model collectors, viz., poly(ethylene glycol) monooleate (PEGMO), ethyl oleate, and maleic acid, as well as the commercial fatty-acid-type collector Atrac 1563, was studied in situ on synthetic hematite using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The adsorption behavior of the studied compounds on hematite was determined to a large extent by the polar headgroup. Adsorption of Atrac and PEGMO as a function of concentration showed good agreement with the Freundlich adsorption model, suggesting energetically heterogeneous adsorption. In situ desorption experiments revealed that a large fraction of the Atrac was weakly attached to the hematite surface, as it was partially removed by flushing with water at pH 8.5 and 10. These results suggest that a separate washing unit after the flotation step could be beneficial in reducing the contamination of iron ore by flotation chemicals.

  • 16.
    Rezaei, Fateme
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Grahn, Mattias
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Thermal management of structured adsorbents in CO2 capture processes2012In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 51, no 10, p. 4025-4034Article in journal (Refereed)
    Abstract [en]

    In order to have an efficient adsorptive separation, structured adsorbents are expected to satisfy not only mass transfer and pressure drop requirements but also thermal management requirements. To what extent the structure of adsorbent affects the thermal behavior of the system is a question which will be addressed in this study. The primary purpose of this study was to assess the performance of alternate adsorbents through development of numerical models for prediction of their thermal behavior under a two-step pressure swing adsorption (PSA) condition. The single-step CO 2 breakthrough and temperature profiles confirmed the efficiency of structured adsorbents in managing the thermal effects evolved in the bed under nonisothermal conditions. Two-step PSA results also showed that under real cyclic processes, and especially during rapid cycling, structured adsorbents maintain their superiority and introduce themselves as potential candidates for advanced PSA units. However, the performance of a structured adsorbent is highly dependent on its dimensions and geometrical parameters describing the structures, and these parameters should be optimized for each separation

  • 17. Rezaei, Fateme
    et al.
    Mosca, Alessandra
    Webley, Paul
    Department of Chemical Engineering, Monash University.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Xiao, Penny
    Department of Chemical Engineering, Monash University.
    Comparison of traditional and structured adsorbents for CO2 separation by vacuum swing adsorption2010In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 49, no 10, p. 4832-4841Article in journal (Refereed)
    Abstract [en]

    The development of structured adsorbents with attractive characteristics is an important step in the improvement of adsorption-based gas-separation processes. The improved features of structured adsorbents include lower energy consumption, higher throughput, and superior recovery and purity of product because of the even flow distribution, very low mass-transfer resistance, and low pressure drop in combination with a reasonable adsorption capacity. This study examines the vacuum-swing adsorption (VSA) CO2 separation performance of structured adsorbents in the form of thin NaX films grown on the walls of ceramic cordierite monoliths, and the results are compared with NaX pellets. Adsorption equilibrium and dynamic properties are explored experimentally. The CO2 breakthrough front for the NaX film grown on the 400 cells/in.2 (cpsi) monolith was close to ideal and indicated that axial dispersion was very small and that the mass-transfer resistance in the film was very low. The breakthrough front for the structured adsorbent with 400 cpsi was sharper than that for the structured adsorbent with 900 cpsi and only shifted to shorter breakthrough times because of the lower amount of zeolite and higher effective diffusivity of the former sample. In addition, the CO2 breakthrough fronts for the 400 and 900 cpsi structured adsorbents were both sharper than the breakthrough front for NaX beads. This indicates that the flow distribution in the structured adsorbents is more even and that the mass-transfer resistance in the film is very low because of the small film thickness and high effective diffusivity for CO2 in the NaX film. Experimental data were used to obtain overall mass-transfer linear-driving-force constants, which were subsequently used in a numerical simulation program to estimate the performance of the adsorbents for CO2/N2 separation in a VSA process. It was found that the recovery of structured adsorbents was superior to that of a packed bed because of the much shorter mass-transfer zone. The purity, on the other hand, was not as high as that obtained with a packed bed because of excessive voidage in the structured adsorbents. Increased cell density or improved zeolite loading of the structured adsorbents would improve the CO2 purity without sacrificing recovery for the structured adsorbents, and this represents a path forward to improved VSA performance for CO2 capture.

  • 18.
    Rownaghi, Ali
    et al.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Hedlund, Jonas
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering.
    Methanol to gasoline-range hydrocarbons: influence of nanocrystal size and mesoporosity on catalytic performance and product distribution of ZSM-52011In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 50, no 21, p. 11872-11878Article in journal (Refereed)
    Abstract [en]

    Improvement of synthesis methods for ZSM-5 zeolite, as a heteregeneous catalyst, is essential for a wide variety of different reactions in the chemical industry. Decreasing zeolite crystal size and introducing mesoporosity into the zeolite structure can improve its performance in catalytic reaction through decreasing the micropore diffusion path length and increasing the external surface area. In this study, three different ZSM-5 zeolites (Nano-ZSM-5, Meso-ZSM-5, and Con-ZSM-5) were prepared by a single-templating procedure, and the reaction of methanol to gasoline-range hydrocarbons was evaluated over synthesized ZSM-5 crystals in a fixed bed continuous flow reactor. Good correlation was observed between catalytic performance, product distribution, mesoporosity, and crystal size of ZSM-5 zeolites. Both nanocrystal and mesoporous ZSM-5 zeolites showed long-term catalytic stability compared with the conventional one. In contrast to conventional ZSM-5 catalyst, the nanocrystal and mesoporous ZSM-5 catalysts showed high selectivities for light olefins and alkyl aromatics, respectively, in the conversion of methanol to gasoline. These results dearly indicate that both crystal size and mesoporosity significantly influence the ZSM-5 lifetime and product distribution

  • 19. Rownaghi, Ali
    et al.
    Taufiq-Yap, Yun Hin
    Novel synthesis techniques for preparation of ultrahigh-crystalline vanadyl pyrophosphate as a highly selective catalyst for n-butane oxidation2010In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 49, no 5, p. 2135-2143Article in journal (Refereed)
    Abstract [en]

    The vanadyl hydrogen phosphate hemihydrate (VOHPO40.5H2O), with well-defined crystal size, has been successfully synthesized for the first time, using a simple one-step solvothermal process that was free of surfactants and water and had a short reaction time and low temperature. The synthesis was performed via the reaction of V2O5 and H3PO4 with an aliphatic alcohol (1-propanol or 1-butanol) at high temperatures (373, 393, and 423 K) in a high-pressure autoclave. The mixture of reactions directly gave the VOHPO40.5H2O, which is a valuable commercial catalyst precursor for the selective oxidation of n-butane to maleic anhydride. The catalyst precursors were dried by microwave irradiation. The reaction conditions (by varying the reducing agent and reaction temperature) were used further for optimization of the crystallite size, surface area, morphology, and activity of the nanostructure of vanadium phosphate oxide [(VO)2P2O7] catalyst. This new method significantly reduced the preparation time and lowered the production temperature (50%) of catalyst precursor (VOHPO40.5H2O), when compared to conventional hydrothermal synthesis methods. The as-prepared (VO)2P2O7 catalyst under various conditions exhibited remarkably different physical and chemical properties, indicating the potential of the suggested method in tuning the crystalline structure and surface area of (VO)2P2O7 to improve its catalytic performance. It was found that the length of the carbon chain in an alcohol and reaction temperature in the solvothermal condition had a great impact on the chemical and physical properties of resulting catalysts. Interestingly, there was no trace of VO(H2PO4)2, which is an impurity noted to be readily formed under solvothermal preparation conditions. The precursors and catalysts were characterized using a combination of powder X-ray diffraction (XRD), Brunauer-Emmett-Teller (BET) surface area measurement, scanning electron microscopy (SEM), and temperature-programmed reduction in hydrogen (H2-TPR). A correlation between the surface area of the catalyst and the activity was observed. Finally, the yield of maleic anhydride was significantly increased from 21% for conventional catalyst to 38% for the new solvothermal catalyst.

  • 20.
    Rownaghi, Ali
    et al.
    Monash University, Melbourne, VIC.
    Taufiq-Yap, Yun Hin
    Rezaei, Fateme
    High Surface Area Vanadium Phosphate Catalysts for n-Butane Oxidation2009In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 48, no 16, p. 7517-7528Article in journal (Refereed)
  • 21.
    Shen, Gulou
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. Division of Energy Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology.
    Held, Christoph
    Laboratory of Thermodynamics, Department of Biochemical and Chemical Engineering, TU Dortmund.
    Mikkola, Jyri Pekka
    Department of Chemistry, Chemical-Biological Centre, Umeå University.
    Lu, Xiaohua
    State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing University of Technology.
    Ji, Xiaoyan
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. Division of Energy Science, Department of Engineering Sciences and Mathematics, Luleå University of Technology.
    Modeling the viscosity of ionic liquids with the electrolyte perturbed-chain statistical association fluid theory2014In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 53, no 52, p. 20258-20268Article in journal (Refereed)
    Abstract [en]

    In this work, the friction theory (FT) and free volume theory (FVT) were combined with the electrolyte perturbed-chain statistical association fluid theory (ePC-SAFT) in order to model the viscosity of pure ionic liquids (ILs) and IL/CO2 mixtures in a wide temperature and pressure (up to 3000 bar) range and with viscosities up to 4000 mPa·s. The ePC-SAFT pure-component parameters for the considered imidazolium-based ILs were adopted from our previous work. These parameters were used to calculate the density and residual pressure of the pure ILs. The density and pressure were then used as inputs for pure-IL viscosity modeling using FVT or FT, respectively. The viscosity-model parameters of FT and FVT were obtained by fitting to experimental viscosity data of imidazolium-based ILs and linearized with the molecular weight of the IL-cation. As a result, the FT viscosity model can more accurately describe the experimental viscosity data of pure ILs than the FVT model, at the cost of an increased number of parameters used in the FT viscosity model. Finally, FT and FVT were applied to model the viscosities of IL/CO2 mixtures in good agreement to experimental data by adjusting one binary viscosity-model parameter between the IL-anion and CO2. The application of FT required fitting the viscosity model parameters of pure ILs to experimental viscosity data of pure ILs and of IL/CO2 mixtures. In contrast, the FVT viscosity model parameters were adjusted to the experimental viscosity data of pure ILs only.

  • 22.
    Shiau, L-D
    et al.
    Michigan State University.
    Berglund, Kris
    Model for a cascade crystallizer in the presence of growth rate dispersion1987In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 26, no 12, p. 2515-2521Article in journal (Refereed)
    Abstract [en]

    A model is developed based on the population balance to relate the resulting crystal size distribution (CSD) from a cascade of mixed suspension, mixed product removal (MSMPR) crystallizers to the growth rate distributions of each stage. This model employs the constant crystal growth (CCG) model, in which it is assumed that an individual crystal has an inherent, constant growth rate, but different crystals might have different inherent growth rates. An explicit recursion formula between the first three moments of the resulting crystal size distribution and the first three moments of growth rate distributions of each stage is presented for a N-stage MSMPR crystallizer. A computer program has been developed to predict the CSD from a three-stage MSMPR crystallizer with continuous seeding into the first stage and growth in the subsequent stages. The model is solved simultaneously with the mass balance by using power law growth kinetics. The CSD in each stage is assumed as a gamma distribution to compute the mean crystal size, production rate, and coefficient of variance.

  • 23.
    Singh, Sandip K.
    et al.
    Chemical & Biological Engineering Department, Montana State University, Bozeman, Montana, United States.
    Savoy, Anthony W.
    Chemical & Biological Engineering Department, Montana State University, Bozeman, Montana, United States.
    Yuan, Zhaoyang
    Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan, United States.
    Luo, Hao
    Department of Chemistry, University of Wisconsin, Madison, Wisconsin, United States.
    Stahl, Shannon S.
    Department of Chemistry, University of Wisconsin, Madison, Wisconsin, United States.
    Hegg, Eric L.
    Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan, United States.
    Hodge, David
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering. Chemical & Biological Engineering Department, Montana State University, Bozeman, Montana, United States.
    Integrated Two-Stage Alkaline-Oxidative Pretreatment of Hybrid Poplar. Part 1: Impact of Alkaline Pre-Extraction Conditions on Process Performance and Lignin Properties2019In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 58, no 35, p. 15989-15999Article in journal (Refereed)
    Abstract [en]

    We previously demonstrated that a two-stage pretreatment comprising of an alkaline pre-extraction followed by a Cu-catalyzed alkaline–oxidative treatment is effective at pretreating hardwoods under relatively mild reaction conditions. In this work, we focus on characterizing how biomass source and reaction conditions used during the alkaline pre-extraction impact the subsequent processing stages as well as lignin yields and properties. Specifically, three hybrid poplars were subjected to the first stage alkaline pre-extraction under various conditions including differences in time (15–300 min), temperature (95–155 °C), and alkali loadings (50–200 mg NaOH/g biomass), and the impact on total mass solubilization, lignin recovery, and lignin purity was determined. Empirical correlations were developed between reaction conditions and mass solubilization and lignin recovery during the pre-extraction stage. For select conditions, lignin properties were assessed and include β-O-4 content determined by 13C NMR, molecular mass distributions as determined by gel permeation chromatography, and susceptibility to depolymerization to aromatic monomers using thioacidolysis and formic acid catalyzed depolymerization. We found alkaline pre-extraction performed at higher temperatures generated lignins exhibiting lower contamination by polysaccharides, lower aromatic monomer yields from depolymerization, lower molar masses, and lower β-O-4 contents relative to the lower temperature pre-extractions. Finally, the pre-extracted biomass from select conditions was assessed for its response to the subsequent Cu-catalyzed alkaline–oxidative treatment and enzymatic hydrolysis. It was demonstrated that minor differences in delignification during pre-extraction have quantifiable impacts on the subsequent efficacy of the second stage of pretreatment and enzymatic hydrolysis with improved lignin removal during the first pre-extraction stage resulting in improved hydrolysis yields.

  • 24.
    Stelte, Wolfgang
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Material Science.
    Sanadi, Anand R.
    Technical University of Denmark.
    Preparation and characterization of cellulose nanofibers from two commercial hardwood and softwood pulps2009In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 48, no 24, p. 11211-11219Article in journal (Refereed)
    Abstract [en]

    The aim of this work was to study the mechanical fibrillation process for the preparation of cellulose nanofibers from two commercial hard- and softwood cellulose pulps. The process consisted of initial refining and subsequent high-pressure homogenization. The progress in fibrillation was studied using different microscopy techniques, mechanical testing, and fiber density measurements of cellulose films prepared after different processing stages. The mechanical properties of cellulose films showed an increase in strength and stiffness with decreasing fiber size, and this stabilized after a certain number of passes in the homogenizer. Atomic force microscopy studies showed that the obtained cellulose nanofibers had diameters in the 10-25-nm range. The significant difference between the two samples was that the ultimate failure strain for cellulose films made of softwood fibers increased during the process whereas it remained constantly low for hardwood cellulose films. This difference could be due to the presence of shorter fibers and more defects in the films. An important point to note is that excessive processing reduced properties, as seen by the decrease in failure strain of softwood fiber films, and could also decrease other properties such as strength if the number of processing steps were further increased.

  • 25.
    Sun, Yunhao
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    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 University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Modeling Thermodynamic Derivative Properties and Gas Solubility of Ionic Liquids with ePC-SAFT2019In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 58, no 19, p. 8401-8417Article in journal (Refereed)
    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.

  • 26.
    Sun, Yunhao
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing.
    Shen, Gulou
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. 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 University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Modeling Viscosity of Ionic Liquids with Electrolyte Perturbed-Chain Statistical Associating Fluid Theory and Free Volume Theory2018In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 57, no 26, p. 8784-8801Article in journal (Refereed)
    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.

  • 27.
    Umeki, Kentaro
    et al.
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    Kirtania, Kawnish
    Luleå University of Technology, Department of Engineering Sciences and Mathematics, Energy Science. Monash University, Melbourne, VIC.
    Chen, Luguang
    Monash University, Melbourne, VIC.
    Bhattacharya, Sankar
    Monash University, Melbourne, VIC.
    Fuel particle conversion of pulverized biomass during pyrolysis in an entrained flow reactor2012In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 51, no 43, p. 13973-13979Article in journal (Refereed)
    Abstract [en]

    This study addresses the change of char morphology and fuel conversion during pyrolysis in a laminar entrained flow reactor by experiments and particle simulation. Three experimental parameters were examined: reaction temperature (1073 and 1273 K); particle size (125–250, 250–500, and 500–1000 μm); and the length of reaction zone (650 and 1885 mm). The scanning electron microscopic (SEM) images showed that biomass swelled during heating and shrank during initial stage of pyrolysis. Then, char morphology transformed to cenospheres after the plastic stage. The yields of solid residue from the experiments were reasonably predicted by particle simulation. To give a guideline for the design of laminar entrained flow pyrolysis reactors, the required reactor length for complete conversion of biomass was also calculated for the pyrolysis. High reaction temperature, small particles, and slower gas flow were favorable for high fuel conversion.

  • 28.
    Uusi-Penttilä, Marketta S.
    et al.
    Michigan State University.
    Richards, Robert J.
    Michigan State University.
    Torgerson, Béatrice A.
    Michigan State University.
    Berglund, Kris
    Spectroscopically determined dielectric constants for various esters1997In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 36, no 2, p. 510-512Article in journal (Refereed)
    Abstract [en]

    Polarity of a solvent can be defined by the Onsager function or the Debye function, which both are functions of the static dielectric constant. Polarity has also been shown to be related to the solvatochromic shifts of the absorption and fluorescence spectra. In this study, the emission maxima of the probe molecule Nile Red were taken in different solvents of known dielectric constants, and relationships between the emission maxima and the Onsager and Debye functions were established. These relationships were used to estimate dielectric constants for various environmentally benign esters.

  • 29.
    Wang, F.
    et al.
    Michigan State University.
    Berglund, Kris
    Monitoring pH swing crystallization of nicotinic acid by the use of attenuated total reflection Fourier transform infrared spectrometry2000In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 39, no 6, p. 2101-2104Article in journal (Refereed)
    Abstract [en]

    Nicotinic acid is crystallized by adding hydrochloric acid (HCl) to a sodium nicotinate aqueous solution. An attenuated total reflection Fourier transform infrared spectrometer is used to monitor the crystallization process of nicotinic acid. The partial least squares method is employed for IR data analysis. The solubility of nicotinic acid varies with the pH and the concentration of sodium nicotinate. The ability to measure the concentration and solubility of nicotinic acid in situ in aqueous mixtures of nicotinic acid and sodium nicotinate provides the possibility of controlling the degree of supersaturation of the solution and in turn optimizing the crystallization conditions for nicotinic acid.Nicotinic acid is crystallized by adding hydrochloric acid (HCl) to a sodium nicotinate aqueous solution. An attenuated total reflection Fourier transform infrared spectrometer is used to monitor the crystallization process of nicotinic acid. The partial least squares method is employed for IR data analysis. The solubility of nicotinic acid varies with the pH and the concentration of sodium nicotinate. The ability to measure the concentration and solubility of nicotinic acid in situ in aqueous mixtures of nicotinic acid and sodium nicotinate provides the possibility of controlling the degree of supersaturation of the solution and in turn optimizing the crystallization conditions for nicotinic acid.

  • 30.
    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 University of Technology, Department of Engineering Sciences and Mathematics, Energy Science.
    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 Thickness2016In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 55, no 1, p. 366-372Article in journal (Refereed)
    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

  • 31.
    Yedur, Sanjay K.
    et al.
    Michigan State University.
    Dulebohn, Joel
    Grand River Technologies, Lansing, MI.
    Werpy, Todd
    Michigan Biotechnology Institute, Lansing.
    Berglund, Kris
    Synthesis and testing of catalysts for the production of maleic anhydride from a fermentation feedstock1996In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 35, no 3, p. 663-671Article in journal (Refereed)
    Abstract [en]

    It is necessary to develop alternate pathways for the production of chemicals that are traditionally produced from fossil fuels to reduce our dependency on nonrenewable energy sources. In this paper, an alternate technology is presented for producing maleic anhydride from a fermentation feedstock. The process involves the catalytic oxydehydrogenation of fermentation-derived succinic anhydride to produce maleic anhydride. Various catalysts have been synthesized and tested for the oxydehydrogenation reaction. Iron phosphate based catalysts are found to be the best on the basis of high conversions and selectivities obtained. The effects of temperature, oxygen concentration, contact time, and the total time on stream on the performance of the catalyst are investigated, and an optimum set of conditions for the operation of the bench-scale reactor is presented. The bulk and surface compositions, the surface areas, and the bulk crystallographic structure of the catalysts are also reported.

  • 32.
    Ying, Zhong-Shu
    et al.
    Chalmers University of Technology, Department of Engineering Chemistry.
    Gevert, Börje
    Chalmers University of Technology, Department of Engineering Chemistry.
    Otterstedt, Jan-Erik
    Chalmers University of Technology, Department of Engineering Chemistry.
    Sterte, Johan
    Large-pore catalysts for hydroprocessing of residual oils1995In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 34, no 5Article in journal (Refereed)
    Abstract [en]

    Hydroprocessing catalysts were prepared using fibrillar alumina and attapulgite as carrier materials and nickel and molybdenum as active substances. With fibrillar alumina as primary particles, a carrier material was obtained which combined a large surface area (138 m2/g) with a large average pore diameter (252 Å). Due to side-by-side association of the fibers, attapulgite did not yield a catalyst carrier with as large pores as was expected. The catalysts were tested for hydroprocessing of an atmospheric petroleum resid, and the results were compared with those obtained for a commercial catalyst with similar loading of nickel and molybdenum. The catalyst prepared using fibrillar alumina as carrier material was more active than the commercial catalyst for hydrodemetalization, equally active for hydrodesulfurization, and less active for hydrodenitrogenation. The catalyst prepared using attapulgite as carrier material was inferior to the other two catalysts in all respects. © 1995 American Chemical Society.

  • 33.
    Yuan, Zhaoyang
    et al.
    Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan, United States.
    Singh, Sandip Kumar
    Department of Chemical & Biological Engineering, Montana State University, Montana, United States.
    Bals, Bryan
    Michigan Biotechnology Institute, Lansing, Michigan, United States.
    Hodge, David B.
    Luleå University of Technology, Department of Civil, Environmental and Natural Resources Engineering, Sustainable Process Engineering. Department of Chemical & Biological Engineering, Montana State University, Bozeman, Montana , United States.
    Hegg, Eric L.
    Department of Biochemistry & Molecular Biology, Michigan State University, East Lansing, Michigan, United States.
    Integrated Two-Stage Alkaline–Oxidative Pretreatment of Hybrid Poplar. Part 2: Impact of Cu-Catalyzed Alkaline Hydrogen Peroxide Pretreatment Conditions on Process Performance and Economics2019In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 58, no 35, p. 16000-16008Article in journal (Refereed)
    Abstract [en]

    Two-stage alkaline/copper 2,2′-bipyridine-catalyzed alkaline hydrogen peroxide (Cu-AHP) pretreatment is an effective strategy for improving the enzymatic digestibility of hybrid poplar. To reduce the chemical inputs and processing costs associated with this process, we investigated the effect of increasing the temperature for both the alkaline pre-extraction and the Cu-AHP pretreatment stages. The results indicate that increasing the alkaline pre-extraction and the Cu-AHP pretreatment temperatures from 30 to 120 and 80 °C, respectively, allowed us to reduce both the pretreatment time of the Cu-AHP stage and the chemical loadings. Incubating alkaline pre-extracted hybrid poplar for 12 h with 10% NaOH (w/w biomass), 8% hydrogen peroxide (w/w biomass), and a Cu2+ and 2,2′-bipyridine (bpy) concentration of 1 mM yielded monomeric sugar yields of approximately 77% glucose and 66% xylose (based on the initial sugar composition) following enzymatic hydrolysis. Technoeconomic analysis (TEA) indicates that these changes to the two-stage alkaline/Cu-AHP pretreatment process could potentially reduce the minimum fuel selling price (MFSP) by more than $1.00 per gallon of biofuel compared to the reference case where both stages were conducted at 30 °C with higher chemical inputs.

  • 34.
    Zhang, Weidong
    et al.
    Department of Automation, Shanghai Jiaotong University.
    Lin, Chen
    Luleå University of Technology, Department of Computer Science, Electrical and Space Engineering, Space Technology.
    Ou, Linlin
    Department of Automation, Shanghai Jiaotong University.
    Algebraic solution to H2 control problems: II. The multivariable decoupling case2006In: Industrial & Engineering Chemistry Research, ISSN 0888-5885, E-ISSN 1520-5045, Vol. 45, no 21, p. 7163-7176Article in journal (Refereed)
    Abstract [en]

    The control of multivariable systems with time delays is an important problem in linear control systems. The goal of this paper is to develop an algebraic design method for multivariable systems with multiple time delays. In the method, the algebra-based input-output design technique is adopted, because it is easy to understand and use, and it requires no state variables. We focus mainly on decoupled response. First, all stabilizing decoupling controllers are parametrized. Second, the optimal decoupling controller is derived by minimizing the sensitivity function. Finally, the performance and robustness are analyzed and a simple tuning rule is developed for quantitative performance and robustness. The most important feature of the proposed method is that the controller is optimal, analytical, and can provide decoupling response. Typical examples are provided to illustrate the proposed method

1 - 34 of 34
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