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  • 1.
    Aaltonen, Harri
    et al.
    Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, FI-00076 Espoo, Finland.
    Sierla, Seppo
    Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, FI-00076 Espoo, Finland.
    Subramanya, Rakshith
    Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, FI-00076 Espoo, Finland.
    Vyatkin, Valeriy
    Luleå tekniska universitet, Institutionen för system- och rymdteknik, Datavetenskap. Department of Electrical Engineering and Automation, School of Electrical Engineering, Aalto University, FI-00076 Espoo, Finland; International Research Laboratory of Computer Technologies, ITMO University, 197101 St. Petersburg, Russia.
    A simulation environment for training a reinforcement learning agent trading a battery storage2021Inngår i: Energies, E-ISSN 1996-1073, Vol. 14, nr 17, artikkel-id 5587Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Battery storages are an essential element of the emerging smart grid. Compared to other distributed intelligent energy resources, batteries have the advantage of being able to rapidly react to events such as renewable generation fluctuations or grid disturbances. There is a lack of research on ways to profitably exploit this ability. Any solution needs to consider rapid electrical phenomena as well as the much slower dynamics of relevant electricity markets. Reinforcement learning is a branch of artificial intelligence that has shown promise in optimizing complex problems involving uncertainty. This article applies reinforcement learning to the problem of trading batteries. The problem involves two timescales, both of which are important for profitability. Firstly, trading the battery capacity must occur on the timescale of the chosen electricity markets. Secondly, the real-time operation of the battery must ensure that no financial penalties are incurred from failing to meet the technical specification. The trading-related decisions must be done under uncertainties, such as unknown future market prices and unpredictable power grid disturbances. In this article, a simulation model of a battery system is proposed as the environment to train a reinforcement learning agent to make such decisions. The system is demonstrated with an application of the battery to Finnish primary frequency reserve markets.

  • 2.
    Abdullahi, Abdirahman
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Techno-economic evaluation of hydrochar via hydrothermal carbonisation of organicresidues2022Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis has investigated the techno-economic feasibility of upgrading the sludge from a chemical pulp mill to hydrochar via hydrothermal carbonization (HTC). The intended use of the hydrochar was to replace fossil coal within metallurgical applications in the iron and steel industry.

    Process models were developed in order to obtain mass and energy balances of the HTC process for different technical configurations. The balances were used to evaluate the economic performance, in terms of hydrochar production cost as well as different profitability parameters. Two main scenarios were investigated:

    Scenario-1: HTC process integrated with the pulp millScenario-2: Stand alone HTC process.To see the effect of having one or two HTC reactors, two cases were developed for each scenario, where the first case used only mixed sludge from the pulp mill as feedstock for the HTC process (case 1, one reactor), while the second case used both mixed sludge and bark as feedstock (case 2, two reactors).

    In scenario 1, the effects on the pulp mill’s mass and energy balances of integrating the HTC process were investigated. The results showed only very small impacts on the pulp mill, due to that the HTC process is significantly smaller than the mill. The total amount of steam to the steam turbine increased by 0.8 % and 0.9 %, for case 1 and 2, respectively. In combination with the removed sludge, which is otherwise combusted in the mill’s socalled power boiler, this entailed a total increase of the wood fuel consumption in the boiler by 3.2 % and 3.6 %, respectively.

    By implementing a second HTC reactor, the production cost of hydrochar could in the integrated scenario (scenario 1) be decreased from 4 600 SEK/ton (case 1) to 3 700 SEK/ton (case 2). The corresponding production costs in the stand alone scenario (scenario 2) amounted to 5 400 SEK/ton (case 1) and 4 200 SEK/ton (case 2), respectively. Both integration with the pulp mill and increasing the HTC production scale were thus found to be strategies that can lead to decreased hydrochar production cost. However, even the lowest production cost noted in this report is significantly higher than the corresponding price of coal. This indicates that other measures are required in order for hydrochar to become cost competitive to fossil coal in the metallurgical industry. Examples are the possibility to use even lower-cost feedstocks, as well as policy tools targeting, e.g., the CO2 emissions from using fossil materials and energy carriers in the iron and steel industry.

    Based on the results from the investment calculation, it is concluded that the HTC process integrated with a pulp mill is preferable compared to a stand alone HTC process. The reason why integrated HTC is preferred is that it gives higher NPV and correspondingly lower payback time, as well as lower hydrochar production costs.

    Fulltekst (pdf)
    fulltext
  • 3.
    Ahlström, Johan
    et al.
    RISE Research Institutes of Sweden, Stockholm, Sweden.
    Jafri, Yawer
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wetterlund, Elisabeth
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. International Institute for Applied Systems Analysis (IIASA), Laxenburg, Austria.
    Furusjö, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Sustainable aviation fuels – Options for negative emissions and high carbon efficiency2023Inngår i: International Journal of Greenhouse Gas Control, ISSN 1750-5836, E-ISSN 1878-0148, Vol. 125, artikkel-id 103886Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mitigating the climate impact from aviation remains one of the tougher challenges in adapting society to fulfill stated climate targets. Long-range aviation cannot be electrified for the foreseeable future and the effects of combusting fuel at high altitude increase the climate impact compared to emissions of green-house gasses only, which further limits the range of sustainable fuel alternatives. We investigate seven different pathways for producing aviation biofuels coupled with either bio-energy carbon capture and storage (BECCS), or bio-energy carbon capture and utilization (BECCU). Both options allow for increased efficiency regarding utilization of feedstock carbon. Our analysis uses process-level carbon- and energy balances, with carbon efficiency, climate impact and levelized cost of production (LCOP) as primary performance indicators.

    The results show that CCS can achieve a negative carbon footprint for four out of the seven pathways, at a lower cost of GHG reduction than the base process option. Conversely, as a consequence of the electricity-intensive CO2 upgrading process, the CCU option shows less encouraging results with higher production costs, carbon footprints and costs of GHG reduction. Overall, pathways with large amounts of vented CO2, e.g., gasification of black liquor or bark, as well as fermentation of forest residues, reach a low GHG reduction cost for the CCS option. These are also pathways with a larger feedstock and corresponding production potential. Our results enable a differentiated comparison of the suitability of various alternatives for BECCS or BECCU in combination with aviation biofuel production. By quantifying the relative strengths and weaknesses of BECCS and BECCU and by highlighting cost, climate and carbon-efficient pathways, these results can be a source of support for both policymakers and the industry.

    Fulltekst (pdf)
    fulltext
  • 4.
    Ahlström, Johan M.
    et al.
    Chalmers University of Technology, Dep. of Space, Earth and Environment, Div. of Energy Technology.
    Pettersson, Karin
    Chalmers University of Technology, Dep. of Space, Earth and Environment, Div. of Energy Technology; RISE Research Institute of Sweden.
    Wetterlund, Elisabeth
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Harvey, Simon
    Chalmers University of Technology, Dep. of Space, Earth and Environment, Div. of Energy Technology.
    Value chains for integrated production of liquefied bio-SNG at sawmill sites: Techno-economic and carbon footprint evaluation2017Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 206, s. 1590-1608Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Industry’s increasing demand for liquefied natural gas could be met in the future by liquefied methane produced from biomass feedstock (LBG - liquefied biogas). This study presents results from an investigation of value chains for integrated production of LBG at a generic sawmill site, based on gasification of sawmill waste streams and forest residues. The objective was to investigate the cost for, as well as the carbon footprint reduction associated with, production and use of LBG as a fuel. Five different LBG plant sizes were investigated in combination with three different sawmill sizes. The resulting cases differ regarding biomass feedstock composition, biomass transportation distances, LBG plant sizes, how efficiently the excess heat from the LBG plant is used, and LBG distribution distances. Pinch technology was used to quantify the heat integration opportunities and to design the process steam network. The results show that efficient use of energy within the integrated process has the largest impact on the performance of the value chain in terms of carbon footprint. The fuel production cost are mainly determined by the investment cost of the plant, as well as feedstock transportation costs, which mainly affects larger plants. Production costs are shown to range from 68 to 156 EUR/MW hfuel and the carbon footprint ranges from 175 to 250 kg GHG-eq/MW hnet biomass assuming that the product is used to substitute fossil LNG fuel. The results indicate that process integration of an indirect biomass gasifier for LBG production is an effective way for a sawmill to utilize its by-products. Integration of this type of biorefinery can be done in such a way that the plant can still cover its heating needs whilst expanding its product portfolio in a competitive way, both from a carbon footprint and cost perspective. The results also indicate that the gains associated with efficient heat integration are important to achieve an efficient value chain.

  • 5.
    Ahlström, Johan M.
    et al.
    Chalmers University of Technology, Dep. of Space. Earth and Environment, Div. of Energy Technology.
    Zetterholm, Jonas
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Pettersson, Karin
    RISE Research Institutes of Sweden.
    Harvey, Simon
    Chalmers University of Technology, Dep. of Space. Earth and Environment, Div. of Energy Technology.
    Wetterlund, Elisabeth
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Economic potential for substitution of fossil fuels with liquefied biomethane in Swedish iron and steel industry: Synergy and competition with other sectors2020Inngår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 209, artikkel-id 112641Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In Sweden, the iron and steel industry (ISI) is a major source of greenhouse gas (GHG) emissions. Most of the emissions result from the use of fossil reducing agents. Nevertheless, the use of fossil fuels for other purposes must also be eliminated in order to reach the Swedish emissions reduction targets. In this study, we investigate the possibility to replace fossil gaseous and liquid fuels used for heating in the ISI, with liquefied biomethane (LBG) produced through gasification of forest residues. We hypothesize that such utilization of fuels in the Swedish ISI is insufficient to independently drive the development of large-scale LBG production, and that other sectors demanding LBG, e.g., for transportation, can be expected to influence the economic potential for the ISI to switch to LBG. The paper investigates how demand for LBG from other sectors can contribute to, or prevent, a phase-out of fossil fuels used for heating purposes in the ISI under different future energy market scenarios, with additional analysis of the impact of a CO2 emissions charge. A geographically explicit cost-minimizing biofuel production localization model is combined with heat integration and energy market scenario analysis. The results show that from a set of possible future energy market scenarios, none yielded more than a 9% replacement of fossil fuels used for heating purposes in the ISI, and only when there was also a demand for LBG from other sectors. The scenarios corresponding to a more ambitious GHG mitigation policy did not achieve higher adoption of LBG, due to corresponding higher biomass prices. A CO2 charge exceeding 200 EUR/tonCO2 would be required to achieve a full phase-out of fossil fuels used for heating purposes in the ISI. We conclude that with the current policy situation, substitution of fossil fuels by LBG will not be economically feasible for the Swedish ISI.

  • 6.
    Ahlström, Johan
    et al.
    Chalmers University of Technology.
    Pettersson, Karin
    Chalmers University of Technology.
    Wetterlund, Elisabeth
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Harvey, Simon
    Chalmers University of Technology.
    Dimensioning of value chains for production of liquefied bio-SNG2016Inngår i: Meeting Sweden's current and future energy challenges, Luleå: Luleå tekniska universitet, 2016, Luleå: Luleå tekniska universitet, 2016Konferansepaper (Annet vitenskapelig)
    Fulltekst (pdf)
    Abstract
    Fulltekst (pdf)
    Presentation
  • 7.
    Ahmed, Kazi Main Uddin
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Bollen, Math H.J
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Alvarez, Manuel
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    A Review of Data Centers Energy Consumption And Reliability Modeling2021Inngår i: IEEE Access, E-ISSN 2169-3536, Vol. 9, artikkel-id 152536Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Enhancing the efficiency and the reliability of the data center are the technical challenges for maintaining the quality of services for the end-users in the data center operation. The energy consumption models of the data center components are pivotal for ensuring the optimal design of the internal facilities and limiting the energy consumption of the data center. The reliability modeling of the data center is also important since the end-user’s satisfaction depends on the availability of the data center services. In this review, the state-of-the-art and the research gaps of data center energy consumption and reliability modeling are identified, which could be beneficial for future research on data center design, planning, and operation. The energy consumption models of the data center components in major load sections i.e., information technology (IT), internal power conditioning system (IPCS), and cooling load section are systematically reviewed and classified, which reveals the advantages and disadvantages of the models for different applications. Based on this analysis and related findings it is concluded that the availability of the model parameters and variables are more important than the accuracy, and the energy consumption models are often necessary for data center reliability studies. Additionally, the lack of research on the IPCS consumption modeling is identified, while the IPCS power losses could cause reliability issues and should be considered with importance for designing the data center. The absence of a review on data center reliability analysis is identified that leads this paper to review the data center reliability assessment aspects, which is needed for ensuring the adaptation of new technologies and equipment in the data center. The state-of-the-art of the reliability indices, reliability models, and methodologies are systematically reviewed in this paper for the first time, where the methodologies are divided into two groups i.e., analytical and simulation-based approaches. There is a lack of research on the data center cooling section reliability analysis and the data center components’ failure data, which are identified as research gaps. In addition, the dependency of different load sections for reliability analysis of the data center is also included that shows the service reliability of the data center is impacted by the IPCS and the cooling section.

  • 8.
    Ahmed, Mukhtiar
    et al.
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Filippov, Andrei
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Johansson, Patrik
    Materials Physics, Department of Physics, Chalmers University of Technology, SE-412 96 Gothenburg, Sweden.
    Shah, Faiz Ullah
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik.
    Pyrrolidium- and Imidazolium-Based Ionic Liquids and Electrolytes with Flexible Oligoether Anions2024Inngår i: ChemPhysChem, ISSN 1439-4235, E-ISSN 1439-7641, Vol. 25, nr 9, artikkel-id e202300810Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new class of fluorine-free ionic liquids (ILs) and electrolytes based on aliphatic flexible oligoether anions, 2-(2-methoxyethoxy)acetate (MEA) and 2-[2-(2-methoxyethoxy)ethoxy]acetate (MEEA), coupled with pyrrolidinium and imidazolium cations is introduced. For the ILs with MEEA anions, Li+ conducting electrolytes are created by doping the ILs with 30 mol % of LiMEEA. The structural flexibility of the oligoether functionality in the anion results in glass transition temperatures (Tg) as low as −60 °C for the neat ILs and the electrolytes. The imidazolium-based ILs and electrolytes reveal better thermal stabilities but higher Tg and lower electrochemical stabilities than the corresponding pyrrolidinium-based analogues. All neat ILs show comparable transport properties for the cations and these decrease by the addition of lithium salt – the pyrrolidinium-based electrolyte being affected the most.

    Fulltekst (pdf)
    fulltext
  • 9.
    Ahsan, Amimul
    et al.
    Department of Civil and Environmental Engineering, Islamic University of Technology (IUT), Gazipur, Bangladesh; Department of Civil and Construction Engineering, Swinburne University of Technology, Melbourne, Australia.
    Ahmad, Nur Syuhada
    Department of Irrigation and Drainage, Kedah, Malaysia.
    Riahi, Ali
    River Engineering and Urban Drainage Research Centre (REDAC), Universiti Sains Malaysia, Nibong Tebal, 14300, Penang, Malaysia.
    Alhaz Uddin, M.
    Department of Civil Engineering, College of Engineering, Jouf University, Sakaka, 42421, Saudi Arabia.
    Hridoy, Daud Nabi
    Department of Civil and Environmental Engineering, Islamic University of Technology (IUT), Gazipur, Bangladesh.
    Shafiquzzaman, M.
    Department of Civil Engineering, College of Engineering, Qassim University, Buraidah, 51452, Saudi Arabia.
    Imteaz, Monzur
    Department of Civil and Construction Engineering, Swinburne University of Technology, Melbourne, Australia.
    Idrus, Syazwani
    Department of Civil Engineering, Universiti Putra Malaysia, Serdang, Selangor, Malaysia.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Atiq, M.A.U.R.
    Centre of Excellence in Water Resources Engineering, University of Engineering and Technology, Lahore, 54890, Pakistan; College of Engineering, Information Technology and Environment, Charles Darwin University, Ellengowan, Dr, Brinkin, NT 0810, Australia.
    Ng, Anne
    College of Engineering, Information Technology and Environment, Charles Darwin University, Ellengowan, Dr, Brinkin, NT 0810, Australia.
    Modeling of a new triangular shape solar distillation system integrated with solar PV panel and DC water heater2023Inngår i: Case Studies in Thermal Engineering, ISSN 2214-157X, Vol. 44, artikkel-id 102843Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new triangular shape solar distillation system is fabricated using locally available materials by integrating with solar PV panel connected to DC water heater. It is designed for the first time to distill saline water or seawater using solar heat energy directly (to heat sample water) and indirectly (through water heater to heat sample water). The trough is made of Plexiglass and painted in black color which is placed inside the triangular frame made of UPVC pipe. The performance of the still is experimented in field. The diurnal variations of solar heat energy, distillate output, various temperatures and relative humidity are observed. A few linear proportional relationships are obtained between the sunlight heat energy and the productivity, between the ambient temperature and the productivity, and between the productivity and water-cover temperature difference. The production rate of the still is higher than the conventional one. An improved simulation model is proposed to estimate the productivity of the still as some previous simulation models cannot estimate the productivity of the solar still precisely. A few new factors are incorporated in the new model as these factors affect the distillate output of the solar still.

    Fulltekst (pdf)
    fulltext
  • 10.
    Ajeel, Raheem K.
    et al.
    Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
    Fayyadh, Saba N.
    Center of Advanced Materials and Renewable Resources, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
    Ibrahim, Adnan
    Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
    Sultan, Sakhr M.
    Solar Energy Research Institute, Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor, Malaysia.
    Najeh, Taoufik
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Drift, underhåll och akustik.
    Comprehensive analysis of heat transfer and pressure drop in square multiple impingement jets employing innovative hybrid nanofluids2024Inngår i: Results in Engineering (RINENG), ISSN 2590-1230, Vol. 21, artikkel-id 101858Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study presents a comprehensive analysis of heat transfer and pressure drop characteristics in square multiple impingement jets utilising a novel class of hybrid nanofluids. This study goes beyond the usual vertical impingement method by looking at the use of oblique impingement in a multiple impinging jet configuration with a hybrid nanofluid. Al2O3–Cu/water with different volume fractions () such as 0.1%, 0.33%, 0.75%, and 1.0% are employed as a working fluid. The purpose of the study is to clarify the impact of the jet angle (β), the jet Reynolds number (Re), extended jet height ), and different volume fraction () on the heat transfer behaviours of the curved target surface. The jet Reynolds number varies from 8000 to 24,000, and five different jet angles (β = 15 , 30°, 45°, 60°, 90 ) and three extended jet heights  = 0.2H, 0.4H, and 0.6H) are adopted. Outcomes disclosed that the highest values of Re and  greatly led to an increase in heat transfer rate and pressure drop of the system. It is uncovered that the heat transfer rate of binary hybrid nanofluids enhances with increasing volume fraction from for all jet angles and Re. Results also exposed that the angle of jet, which is 45°, gives a higher Nusselt number compared to other angles proposed in this study, and the maximum boost reaches 35%. Besides, despite the fact that reducing the height of the extended jet yields enhanced heat transfer rates in comparison to other methods, it concurrently results in an elevation in pressure drop. Finally, this research yielding insights that can be applied to improve the efficiency of heat transfer systems in practical applications.

    Fulltekst (pdf)
    fulltext
  • 11.
    Alam, Md Tabrez
    et al.
    Energy & Thermofluids Lab Department of Chemical and Biochemical Engineering Indian Institute of Technology Patna Amhara Road, Bihta Patna 801106, Bihar, India.
    Raj, Aashna
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Singh, Lalan K.
    Energy & Thermofluids Lab Department of Chemical and Biochemical Engineering Indian Institute of Technology Patna Amhara Road, Bihta Patna 801106, Bihar, India.
    Gupta, Anoop K.
    Energy & Thermofluids Lab Department of Chemical and Biochemical Engineering Indian Institute of Technology Patna Amhara Road, Bihta Patna 801106, Bihar, India.
    A comparative analysis on charging performance of triplex-tube heat exchanger under various configurations of composite phase change material2024Inngår i: Thermal Science and Engineering Progress, E-ISSN 2451-9049, Vol. 51, artikkel-id 102655Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In present work, the melting performance of triplex-tube latent heat thermal energy storage (LHTES) unit was numerically studied using equal volumes of PCM and metal foam composite PCM (CPCM) in various arrangements. For the n-eicosane (as PCM), the study was conducted at the fixed Rayleigh number (Ra) = 4.08x107, Prandtl number (Pr) = 62.9, and Stefan number (Ste) = 0.14. The results showed that positioning the metal foam on the bottom side and distributing segmented CPCM with alternating PCM zones effectively improved the system performance. Moreover, this also prevents the overheating of thermal layers in the LHTES unit. While the model labelled M2 exhibited the highest economic efficiency among all isotropic models, its low dimensionless thermal energy storage (TES) density (i.e., q’ ∼ 0.6) led this study to focus on models falling under the category having a TES density of ∼ 0.8. Compared to a pure PCM model, the configurations under equal volume ratio category demonstrated up to ∼ four times higher TES rate (p’) and the significant reduction of ∼ 75 % in melting time. The optimized isotropic model achieved the highest TES rate per unit cost with peak value of ∼ 3 at a price ratio (N) of 1. Lastly, the testing of metal foam anisotropy on the chosen design showed a substantial increase in melting/heat storage rates. The largest drop of ∼ 33 % in the total melting time was noticed for model M2 as compared to isotropic case.

  • 12.
    Alawi, Omer A.
    et al.
    Department of Thermofluids, School of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Bahru, Malaysia.
    Kamar, Haslinda Mohamed
    Department of Thermofluids, School of Mechanical Engineering, Universiti Teknologi Malaysia, 81310 UTM Skudai, Johor Bahru, Malaysia.
    Falah, Mayadah W.
    Building and Construction Techniques Engineering Department, Al-Mustaqbal University College, Hillah 51001, Iraq.
    Hussein, Omar A.
    Petroleum System Control Engineering Department, College of Petroleum Processes Engineering, Tikrit University, Tikrit, Iraq.
    Abdelrazek, Ali H.
    Department of Mechanical Precision Engineering, Takasago i-Kohza, Malaysia-Japan International Institute of Technology, Universiti Teknologi Malaysia, Kuala Lumpur, Malaysia.
    Ahmed, Waqar
    Greater Bay Area Institute of Precision Medicine, Guangzhou 511462, China.
    Eltaweel, Mahmoud
    School of Physics, Engineering and Computer Science, University of Hertfordshire, Hatfield, AL10 9AB, United Kingdom.
    Homod, Raad Z.
    Department of Oil and Gas Engineering, Basrah University for Oil and Gas, Basrah, Iraq.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Yaseen, Zaher Mundher
    Civil and Environmental Engineering Department, King Fahd University of Petroleum and Minerals, Dhahran 31261, Saudi Arabia.
    Thermohydraulic performance of thermal system integrated with twisted turbulator inserts using ternary hybrid nanofluids2023Inngår i: Nanotechnology Reviews, ISSN 2191-9089, E-ISSN 2191-9097, Vol. 12, nr 1, artikkel-id 20220504Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Mono, hybrid, and ternary nanofluids were tested inside the plain and twisted-tape pipes using k-omega shear stress transport turbulence models. The Reynolds number was 5,000 ≤ Re ≤ 15,000, and thermophysical properties were calculated under the condition of 303 K. Single nanofluids (Al2O3/distilled water [DW], SiO2/DW, and ZnO/DW), hybrid nanofluids (SiO2 + Al2O3/DW, SiO2 + ZnO/DW, and ZnO + Al2O3/DW) in the mixture ratio of 80:20, and ternary nanofluids (SiO2 + Al2O3 + ZnO/DW) in the mixture ratio of 60:20:20 were estimated in different volumetric concentrations (1, 2, 3, and 4%). The twisted pipe had a higher outlet temperature than the plain pipe, while SiO2/DW had a lower Tout value with 310.933 K (plain pipe) and 313.842 K (twisted pipe) at Re = 9,000. The thermal system gained better energy using ZnO/DW with 6178.060 W (plain pipe) and 8426.474 W (twisted pipe). Furthermore, using SiO2/DW at Re = 9,000, heat transfer improved by 18.017% (plain pipe) and 21.007% (twisted pipe). At Re = 900, the pressure in plain and twisted pipes employing SiO2/DW reduced by 167.114 and 166.994%, respectively. In general, the thermohydraulic performance of DW and nanofluids was superior to one. Meanwhile, with Re = 15,000, DW had a higher value of η Thermohydraulic = 1.678

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  • 13.
    Alfieri, Luisa
    et al.
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Bracale, Antonio
    Department of Engineering, University of Naples Parthenope, Centro Direzionale of Naples.
    Carpinelli, Guido
    Department of Electrical Engineering and Information Technology, University of Naples Federico II.
    Larsson, Anders
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    A Wavelet-Modified ESPRIT Hybrid Method for Assessment of Spectral Components from 0 to 150 kHz2017Inngår i: Energies, E-ISSN 1996-1073, Vol. 10, nr 1, artikkel-id 97Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Waveform distortions are an important issue in distribution systems. In particular, the assessment of very wide spectra, that include also components in the 2-150 kHz range, has recently become an issue of great interest. This is due to the increasing presence of high-spectral emission devices like end-user devices and distributed generation systems. This study proposed a new sliding-window wavelet-modified estimation of signal parameters by rotational invariance technique (ESPRIT) method, particularly suitable for the spectral analysis of waveforms that have very wide spectra. The method is very accurate and requires reduced computational effort. It can be applied successfully to detect spectral components in the range of 0-150 kHz introduced both by distributed power plants, such as wind and photovoltaic generation systems, and by end-user equipment connected to grids through static converters, such as fluorescent lamps.

  • 14.
    Alfjorden, Rikard
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Black liquor to advanced biofuel: A techno-economic assessment2019Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis looked at a biorefinery pilot plant that converted lignin in black liquor into biofuel. A heat/mass balance was made which was used to create a heat/mass balance for a theoretical large-scale plant. This then created the CAPEX for building the plant. OPEX for the largescale plant and income from sold biofuels was calculated and payback time found. This was done for three different cases with different flows and yield to optimize the plant. A sensitivity analysis was then made to find the most important parameters regarding CAPEX, OPEX and payback time.

    Fulltekst (pdf)
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  • 15.
    Alriksson, Stina
    et al.
    Linnéuniversitetet.
    Grip, Carl-Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Steel industry environmental objectives: stakeholder preference assessment using conjoint analysis2013Inngår i: Ironmaking & steelmaking, ISSN 0301-9233, E-ISSN 1743-2812, Vol. 40, nr 8, s. 605-612Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The Swedish steel industry has combined traditional methods such as life cycle analysis with less traditional methods such as preference analysis in order to move towards a closed steel eco cycle. The paper describes the use of conjoint analysis to study preferences of six different stakeholder groups regarding four environmental objectives (reduction in carbon dioxide emissions, reduced use of non-renewable resources, reduced use of non-renewable energy and weight reduction in products) and to identify gaps in preferences between the stakeholder groups. Our results suggested that there was a difference in preference between the stakeholder groups: respondents that were closer to the steel industry favoured all four environmental objectives, while members of public and political decision makers preferred a reduction in carbon dioxide emissions. One of the conclusions of our study is that there is a need of improved information to clients and public on the environmental benefits of product weight reduction.

  • 16.
    Alsaffar, Abdul Kareem K.
    et al.
    Engineering Faculty, University of Babylon, Babylon, Iraq.
    Alquzweeni, Saif S.
    Engineering Faculty, University of Babylon, Babylon, Iraq.
    Al-Ameer, Lubna R.
    Al-Zahraa University for Women, Kerbala, Iraq.
    Ali, Abduljabar H.
    Mechanical Engineering, Al-Mustaqbal University, Al-Hillah, Iraq.
    Mohamed, Ahmed
    School of Civil Engineering and Built Environment, Liverpool John Moores University, Liverpool, L3 3AF, UK.
    Aldaihani, Humoud M.
    Geotechnical and Geoenvironmental Engineering, Implementation Construction Sector, Public Authority for Housing Welfare, Kuwait.
    Reham, A.
    Engineering Faculty, University of Babylon, Babylon, Iraq.
    Al-Ansari, Nadhir
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Geoteknologi.
    Al-Hashimi, Osamah
    School of Civil Engineering and Built Environment, Liverpool John Moores University, Liverpool, L3 3AF, UK.
    Shubbar, Ali
    School of Civil Engineering and Built Environment, Liverpool John Moores University, Liverpool, L3 3AF, UK.
    Khan, Mohammad Amir
    Department of Civil Engineering, Galgotias College of Engineering, Greater Noida, 201310, India.
    Hashim, Khalid
    School of Civil Engineering and Built Environment, Liverpool John Moores University, Liverpool, L3 3AF, UK.
    Development of eco-friendly wall insulation layer utilising the wastes of the packing industry2023Inngår i: Heliyon, E-ISSN 2405-8440, Vol. 9, nr 11, artikkel-id e21799Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Efficient thermal insulation materials considerably lower power consumption for heating and cooling of buildings, which in turn minimises CO2 emissions and improves indoor comfort conditions. However, the selection of suitable insulation materials is governed by several factors, such as the environmental impact, health impact, cost and durability. Additionally, the disposal of used insulation materials is a major factor that affects the selection of materials because some materials could be very toxic for humans and the environment, such as asbestos-containing materials. Therefore, there is a continuous research effort, in both industry and academia, to develop sustainable and affordable insulation materials. In this context, this work aims at utilising the packing industry wastes (cardboard) to develop an eco-friendly insulation layer, which is a biodegradable material that can be disposed of safely after use. Experimentally, wasted cardboard was collected, cleaned, and soaked in water for 24 h. Then, the wet cardboard was minced and converted into past papers, then cast in square moulds and left in a ventilated oven at 75 °C to dry before de-moulding them. The produced layers were subjected to a wide range of tests, including thermal conductivity, acoustic insulation, infrared imaging and bending resistance. The obtained results showed the developed material has a good thermal and acoustic insulation performance. Thermally, the developed material had the lowest thermal conductivity (λ) (0.039 W/m.K) compared to the studied traditional materials. Additionally, it successfully decreased the noise level from 80 to about 58 dB, which was better than the efficiency of the commercial polyisocyanurate layer. However, the bending strength of the developed material was a major drawback because the material did not resist more than 0.6 MPa compared to 2.0 MPa for the commercial polyisocyanurate and 70.0 MPa for the wood boards. Therefore, it is recommended to investigate the possibility of strengthening the new material by adding fibres or cementitious materials.

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  • 17.
    Amara, S.
    et al.
    Materials and Renewable Energy Research Unit (URMER), University of Tlemcen, BP 119 Tlemcen, Algeria.
    Baghdadli, T
    Materials and Renewable Energy Research Unit (URMER), University of Tlemcen, BP 119 Tlemcen, Algeria.
    Nordell, Bo
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Arkitektur och vatten.
    Planned Investigation of UTES Potential in Algeria2019Inngår i: The 2nd International Conference on Green Civil and Environmental Engineering 4–6 September 2019, Malang, East Java, Indonesia, Institute of Physics (IOP), 2019, artikkel-id 012022Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The unbalance between supply and demand of heat can be managed by thermal energy storage (TES). For large-scale systems the underground is used as storage medium or storage volume. Aquifer storage (ATES) is most suitable for very large applications, Borehole storage (BTES) the most general system in all scales and the rock cavern storage (CTES) is best suited for extremely high loading/extraction loads. The construction of any of these systems requires knowledge about site-specific properties of the ground i.e. geology and groundwater conditions. Current paper gives a brief review of the potential and advantage of Underground Thermal Energy Storage (UTES) technology utilization in buildings for the hard climate.

  • 18.
    Amjad, Um-e-Salma
    et al.
    Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Tajjamal, Arshia
    Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Ul-Hamid, Anwar
    Core Research Facilities, King Fahd University of Petroleum & Minerals, Dhahran 31261, Saudi Arabia.
    Faisal, Abrar
    Luleå tekniska universitet, Institutionen för samhällsbyggnad och naturresurser, Kemiteknik. Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Zaidi, Syed Ammar Hussain
    Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Sherin, Lubna
    Department of Chemistry, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Mir, Amna
    Department of Physics, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Mustafa, Maria
    Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Ahmad, Nabeel
    Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Hussain, Murid
    Department of Chemical Engineering, COMSATS University Islamabad, Lahore Campus, Defence Road, Off Raiwind Road, Lahore 54000, Pakistan.
    Park, Young-Kwon
    School of Environmental Engineering, University of Seoul, Seoul 02504, Republic of Korea.
    Catalytic cracking of polystyrene pyrolysis oil: Effect of Nb2O5 and NiO/Nb2O5 catalyst on the liquid product composition2022Inngår i: Waste Management, ISSN 0956-053X, E-ISSN 1879-2456, Vol. 141, s. 240-250Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The catalytic cracking of polystyrene pyrolysis oil was investigated over a Nb2O5 and a NiO/Nb2O5 catalyst in a fixed bed reactor. First, the pyrolysis of two different polystyrene feedstock (polystyrene foam and polystyrene pellet) was carried out in a semi-batch reactor, and the resulting polystyrene pellets pyrolysis oil was selected for catalytic cracking reaction because of its high liquid yield (85%). Catalytic cracking experiments were then performed at different temperatures (350–500 °C) using Nb2O5 or NiO/Nb2O5 catalyst. Gas chromatography–mass spectrometry analysis of liquid product obtained from the catalytic cracking process showed that the dimers in the pyrolysis oil were converted to monomers during the catalytic cracking process. The catalytic cracking results also showed that the NiO/Nb2O5 catalyst (having slightly higher acidic sites) had slightly higher activity for monomer conversion than the Nb2O5 catalyst (having less acidic sites). X-ray diffraction, transmission electron microscopy, pyridine Fourier transform infrared spectroscopy, NH3 Temperature Programmed Desorption and X-ray photoelectron spectroscopy were used to characterize the catalyst. The highest catalytic cracking activity was observed at 400 °C with the Nb2O5 catalyst with 4% toluene, 6% ethylbenzene, approximately 50% styrene, 13% α-methyl styrene, and only 6% of dimers in the liquid oil. The increase in temperature positively affected the yield of gases during catalytic cracking process.

  • 19.
    Amoignon, Olivier
    Luleå tekniska universitet.
    Pressure losses and temperatures in pressurised cyclone gasifier1995Rapport (Annet vitenskapelig)
  • 20.
    Anderson, Jan-Olof
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Westerlund, Lars
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Analysis of the heat demand in batch kilns2012Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    During the production of lumber more than half of the entering timber to the sawmill becomes biomass. About 12 %wt of the entering timber is combusted to supply heat for the sawmill. Major part of the heat is supply the kilns. Due to the high evacuation losses the energy efficiency in a traditional drying kiln is only 13 %. This makes the lumber drying to a low and ineffective process in an energy point of view.Forced drying technologies are a compromise between high lumber quality, low lead time and decreased energy use. Often is the quality and lead time prioritised. This paper advises an appropriate method to simulate the energy efficiency when drying lumber in a batch kiln. To ensure real life drying conditions, with sufficient quality and lead time the initial conditions were made from simulated drying schemes, from simulation program called Torksim. By combine thermodynamics and psychrometric relationship, the energy streams and losses during the drying scheme were established. The program can be used to compare several drying conditions and clarify the magnitude of losses. Different types of technologies affecting the kiln energy efficiency and to compare drying conditions to each other. For instance heat exchanger, heat pumps, condense walls, absorption system etc.The used drying conditions are suitable for north European lumber and climate, but the initial conditions can be changed for analyses of other types of drying conditions. The program is a usable tool to analyses different types of technologies effect on the kiln energy efficiency and to compare drying conditions and different drying scheme to each other.

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  • 21.
    Andersson, André
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Utredning av potentiella prosumenter anslutna till Härnösands fjärrvärmenät2019Independent thesis Basic level (professional degree), 180 hpOppgave
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  • 22.
    Andersson, H.M.
    et al.
    Luleå tekniska universitet.
    Lundström, T. Staffan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Gebart, B. Rikard
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Synnergren, Per
    Luleå tekniska universitet.
    Application of digital speckle photography to measure thickness variations in the vacuum infusion process2003Inngår i: Polymer Composites, ISSN 0272-8397, E-ISSN 1548-0569, Vol. 24, nr 3, s. 448-455Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    A new method to measure the movement of the flexible bag used in vacuum infusion is presented. The method is based on an in-house developed stereoscopic digital speckle photography system (DSP). The advantage with this optical method, which is based on cross-correlation, is that the deflection of a large area can be continuously measured with a great accuracy (down to 10 μm. The method is at this stage most suited for research but can in the long run also be adopted in production control and optimization. By use of the method it was confirmed that a ditch is formed at the resin flow front and that there can be a considerable and seemingly perpetual compaction after complete filling. The existence of the ditch demonstrates that the stiffness of the reinforcement can be considerably reduced when it is wetted. Hence, the maximum fiber volume fraction can be larger than predicted from dry measurements of preform elasticity. It is likely that the overall thickness reduction after complete filling emanates from lubrication of the fibers combined with an outflow of the resin. Besides, the cross-linking starts and the polymer shrinks. Hence, the alteration in height will continue until complete cross-linking is reached.

  • 23.
    Andersson, Jan-Olof
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Energy and Resource Efficiency in Convective Drying Systems in the Process Industry2014Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Growing concern about environmental problems has increased the public’s interest in energy usage. The subsidies for biomass, together with the rising energy prices have madebiomass a desirable product on the energy market. This has led to higher biomass prices and an increased interest in improving the resource and energy efficiency associated withbiomass production. Biofuel is an interesting substitute for fossil fuels to decrease the greenhouse gas emissions. One challenge with biofuels is to find sufficient amounts of biomass since the foresting is already close to its maximum sustainable capacity. Sawmills are important suppliers to the biomass market, since the sawmill industries produce a significant part of the available biomass. This Doctoral thesis focuses on strategies to decrease biomass usage in order to increase the biomass availability at the market. This is done through mapping and system analysis of energy and material streams for process industries using convective drying techniques. The energy analysis is mainly done through thermodynamics and psychrometry. Available state-of-the-art technologies on the market are studied to determine their potential for decreasing the total energy usage in sawmills. Integration possibilities between biomass consumers are also investigated through process integration with mathematical programming and pinch analysis. Energy efficiency of berry drying in a juice plant is also studied. The main conclusions are as follows. The heat demand of drying lumber in Swedish sawmills is about 4.9 TWh/year. Using available state-of-the-art technologies (heat pumps,heat exchangers and open absorption system) it is possible to reduce the energy usagesubstantially. If the recovered heat is used for heat sinks inside, or close to, the sawmill, the energy efficiency can be improved significantly. Using mechanical heat pumps nationally could save 4.9 TWh/year ofheatandgenerate0.62 TWh/year of surplus heat, at the cost of 1TWh/year of electricity. Using open absorption systems nationally, could save 3.4 TWh/year of heat, at the cost of only 0.05 TWh/year of electricity. Saving this heat means that an even larger amount of biomass will be saved, since there are heat losses during the combustion and distribution. Another way of saving energy is to displacethe starting time between batch kilns, and recycle evacuation air between the kilns. Nationally, this could save 0.44 TWh/year of heat. Industrial site integration between sawmills and the main biomass users (pelleting plants an d CHP plants) can decrease the use of biomass in the industrial site with 43% wt compared to a standalone site with a comparable production. Nationally, this could save up to 7.1 TWh/year of biomass. Despite the significant savings in terms of resources, it is not profitable due to the currentprice ratio between district heating and biomass. Finally, drying and separationof berry press cake in a juice plant is found to be possible using only energy from the exhaust gases of the steam boiler, if the drying air is sufficientlyrecycled. Instead of composting the press cake, the dried and separated skins and seeds could then be sold.

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  • 24.
    Andersson, Jan-Olof
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Improving energy use in sawmills: from drying kilns to national impact2012Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Increased concern about environmental problems has amplified the public`s interest inenergy usage. The improved subsidies for biomass, together with the rising energy priceshave made biomass a desirable product on the energy market. Energy intensive industries inthe field of wood and biomass now have nowadays an opportunity to decrease energyconsumption and to sell their biomass surplus on the energy market.This Licentiate thesis focuses on strategies to decrease biomass usage in sawmill industriesin order to increase their surplus biomass and increase their profit. This is done throughsystem analysis of sawmill industries in terms of mass and energy flows. The energyanalysis focuses on the drying kiln using psychrometric and thermodynamic relationships.State-of-the-art technologies, available on the market, have been studied to determine theirpossible effect on the total energy usage in the sawmills.This study was undertaken to determine the national use of energy due to sawmills and thepotential magnitude of improvements. Sawmills are important suppliers to the biomassmarket, since medium to large capacity sawmills contribute with 95% of the Swedish annuallumber (sawn boards) production (17.3 Mm3) with a lumber interchange of only 47%. Therest of the timber (unsawn logs) is transformed into biomass through the lumber productionprocesses. An essential part (12%) of the timber is used for supplying heat to the productionprocesses, mainly to the drying process which is the most time and heat consuming processin the sawmill. The main conclusions are that the heat demand for drying lumber in Swedishsawmills was found to be 4.9 TWh per year and the drying process can be made moreeffective by use of state-of-the-art technologies. Hence the internal use of biomass insawmills can be decreased, thereby increasing the biomass that can be sold to the marketand/or to generate heat and/or electricity, resulting in more profitable sawmills and asignificant increased supply of biomass to the market.It was also found that with available state-of-the-art technologies it is possible to recycle theheat in the evacuated air from the dryer, and if the recovered heat is used for heat sinksinside or close to the sawmill a large decrease of the energy usage can be achieved. If thetechnologies are implemented up to 5.56 TWh of equivalent biomass can be saved,depending on the technology, the specific sawmill conditions, kiln settings and dryingsystem operation. However, some of the considered technologies consume a substantialamount of electricity, so the economic benefit should be carefully evaluated.

    Fulltekst (pdf)
    FULLTEXT01
  • 25.
    Andersson, Jan-Olof
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Elfgren, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Grip, Carl-Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Improved energy efficiency in juice production through waste heat recycling2013Inngår i: International Conference on Applied Energy, ICAE 2013, 2013, artikkel-id ICAE2013-514Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The global demand for Nordic wild berries has increased steadily, partly due to their healthy properties and their good taste. Juice concentrate is produced by pressing berries and heating up the juice. The by-products are berry skins and seeds. Traditionally, the by-products have been composted. Higher competiveness can be achieved by decreasing the production cost and increasing the product values. The berry skins and seeds have a commercial value since they are rich in vitamins and nutrients. To use and sell these by-products, they need to be separated from each other and dried to a moisture content of less than 10 %wt. A berry juice industry in the north of Sweden has been studied in order to increase the energy and resource efficiency and optimize the quality and yield of different berry fractions. This was done by means of process integration with thermodynamics and psychrometry along with measurements of the berry juice production processes. Our calculations show that the drying system could be operated at full without any external heat supply. This could be achieved by increasing the efficiency of the dryer by recirculating 80 % of the drying air and by heating the air with heat from the flue gases from the industrial boiler. This change would decrease the need for heat in the dryer with about 64 %. The total heat use for the plant could thereby be decreased from 1204 kW to 1039 kW. The proposed changes could be done without compromising the production quality or the lead time.

    Fulltekst (pdf)
    fulltext
  • 26.
    Andersson, Jan-Olof
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Elfgren, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Westerlund, Lars
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Improved energy efficiency in juice production through waste heat recycling2014Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 130, nr S1, s. 757-763Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Berry juice concentrate is produced by pressing berries and heating up the juice. The by-products are berry skins and seeds in a press cake. Traditionally, these by-products have been composted, but due to their valuable nutrients, it could be profitable to sell them instead. The skins and seeds need to be separated and dried to a moisture content of less than 10 %wt (on dry basis) in order to avoid fermentation. A berry juice plant in the north of Sweden has been studied in order to increase the energy and resource efficiency, with special focus on the drying system. This was done by means of process integration with mass and energy balance, theory from thermodynamics and psychrometry along with measurements of the juice plant. Our study indicates that the drying system could be operated at full capacity without any external heat supply using waste heat supplied from the juice plant. This would be achieved by increasing the efficiency of the dryer by recirculation of the drying air and by heat supply from the flue gases of the industrial boiler. The recirculation would decrease the need of heat in the dryer with about 52%. The total heat use for the plant could thereby be decreased from 1262 kW to 1145 kW. The improvements could be done without compromising the production quality.

  • 27.
    Andersson, Jan-Olof
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Toffolo, Andrea
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Improving energy efficiency of sawmill industrial sites by integration with pellet and CHP plants2013Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 111, s. 791-800Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    An essential strategy to lower energy and resources consumption is the development of highly integrated industrial sites including different kind of plants complementing one another. Sawmills are huge biomass suppliers to other industries, such as pulp and paper mills, pellet plants and CHP plants, and part of the biomass is also used for the internal heat requirement. In this paper the integration of a sawmill with a pellet plant and a CHP plant is investigated using advanced process integration techniques, so that the thermal energy and the electricity produced in the CHP plant by burning part of the sawmill biomass output are used for the heat and power requirements of the other two industries. The results show that up to 18% of the biomass by-products from the sawmill can be saved, but from the economic point of view the ratio between prices of the thermal energy sold for district heating and the low quality biomass has to be lower than the present one to make the integrated design solution more attractive than separate plant operation.

  • 28.
    Andersson, Jan-Olof
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Westerlund, Lars
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Improved energy efficiency in sawmill drying system2014Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 113, s. 891-901Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The worldwide use of biomass has increased drastically during the last decade. At Swedish sawmills about half of the entering timber becomes lumber, with the remainder considered as by-product (biomass). A significant part of this biomass is used for internal heat production, mainly for forced drying of lumber in drying kilns. Large heat losses in kilns arise due to difficulties in recovering evaporative heat in moist air at low temperatures. This paper addresses the impact of available state-of-the-art technologies of heat recycling on the most common drying schemes used in Swedish sawmills. Simulations of different technologies were performed on an hourly basis to compare the heat and electricity demand with the different technologies. This was executed for a total sawmill and finally to the national level to assess the potential effects upon energy efficiency and biomass consumption. Since some techniques produce a surplus of heat the comparison has to include the whole sawmill. The impact on a national level shows the potential of the different investigated techniques. The results show that if air heat exchangers were introduced across all sawmills in Sweden, the heat demand would decrease by 0.3 TWh/year. The mechanical heat pump technology would decrease the heat demand by 5.6 TWh/year and would also produce a surplus for external heat sinks, though electricity demand would increase by 1 TWh/year. The open absorption system decreases the heat demand by 3.4 TWh/year on a national level, though at the same time there is a moderate increase in electricity demand of 0.05 TWh/year. Introducing actual energy prices in Sweden gives an annual profit (investment cost excluded) on national level for the open absorption system of almost 580 million SEK. For the mechanical heat pump technology the profit is 204 million SEK and for the traditional heat exchanger the profit is significant lower. It has been found that a widespread implementation of available energy recovery technologies across Swedish sawmills would result in substantial savings of biomass for other purposes in the society

  • 29.
    Andersson, Jan-Olof
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Westerlund, Lars
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    MIND based optimisation and energy analysis of a sawmill production line2010Inngår i: PRES 2010: 13th Conference on Process Integration, Modelling and Optimisation for Energy Saving and Pollution Reduction, 28 August - 1 September 2010, Prague, Czech Republic, 2010, s. 1-5Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The lumber drying process uses about 80 % of the total heat consumption in sawmills. Efforts to increase energy efficiency in lumber kilns were very restricted due to the low biomass prices between the 80th and 90th. Today with higher production and biomass prices, companies want to decrease their own use of biomass and increase the heating system efficiency. The study proposes alternative ways to reduce the heat consumption at batch kilns by recirculation of the evacuation air and addresses particular problem encountered in sawmills. Which produce their own heat and suffer from bottlenecks in the heating system due to high heat load from the dryers and increased production. The study shows the possibility to recycle the evacuation air from each kiln which reduces the overall heat consumption of the kilns by 12 %. At nationally basis this corresponds to a decrease of heat consumption of 440 GWh annually, among Swedish sawmill. This will decrease the individual heat consumption of the kilns, heat load in the heating system and the bottleneck effect in the drying process. The decreased own use of biomass brings benefits of more available biomass to the market and increased profits for the sawmill.

    Fulltekst (pdf)
    FULLTEXT01
  • 30.
    Andersson, Jan-Olof
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Westerlund, Lars
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Surplus biomass through energy efficient kilns2011Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 88, nr 12, s. 4848-4853Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The use of biomass in the European Union has increased since the middle of the 1990s, mostly because of high subsidies and CO2 emission regulation through the Kyoto protocol. The sawmills are huge biomass suppliers to the market; out of the Swedish annual lumber production of 16.4 Mm3, 95% is produced by medium to large-volume sawmills with a lumber quotient of 47%. The remaining part is produced as biomass. An essential part (12%) of the entering timber is used for supply of heat in their production processes, mostly in the substantial drying process. The drying process is the most time and heat consuming process in the sawmill. This study was undertaken to determine the sawmills’ national use of energy and potential magnitude of improvements. If the drying process can be made more effective, sawmills’ own use of biomass can be decreased and allow a considerably larger supply to the biomass market through processed or unprocessed biomass, heat or electricity production. The national electricity and heat usage when drying the lumber have been analysed by theoretical evaluation and experimental validation at a batch kiln. The main conclusion is that the heat consumption for drying lumber among the Swedish sawmills is 4.9 TW h/year, and with available state-of-the-art techniques it is possible to decrease the national heat consumption by approximately 2.9 TW h. This additional amount of energy corresponds to the market’s desire for larger energy supply.

  • 31.
    Andersson, Jim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Systems Analysis of Chemicals Production via Integrated Entrained Flow Biomass Gasification: Quantification and improvement of techno-economic performance2016Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Lignocellulosic biomass gasification is a promising production pathway for green chemicals, which can support the development towards a more sustainable society where fossil fuels are replaced. To be able to compete with fossil fuels, a highly efficient production of biomassbased products is required in order to maximize overall process economics and to minimizenegative environmental impact. Large production plants will likely be required to obtain favourable economy-of-scale effects and reasonable production cost. Entrained flow gasification (EFG) is a favourable technology due to its suitability for large-scale implementation and ability to produce a high quality syngas from various biomass feedstocks. In order to estimate overall energy efficiency and production costs for gasification-based biorefineries, it is important to be able to characterise the gasifiers’ performance. This in turnrequires reliable estimations of the gasification process. Integration of EFG-based biorefineries with existing pulp mills or other large-scale forestindustries can be achieved by integration of material and/or energy flows, as well as by coutilisation of process equipment. This could potentially induce both technical and economic added-values. At chemical pulp mills, an important feedstock for green chemical production may be the black liquor from the pulp production, since it provides an attractive combinationof advantages. The black liquor availability is, however, directly correlated to the pulp production (i.e. the mill size) and the potential green chemical production volume via pure black liquor gasification (BLG) is therefore limited.In this thesis, two systems are considered that expand on the BLG concept with the intent to increase the chemical production volume, since this could generate positive economy-of-scale effects and is a rather unexamined area. In addition to this, an EFG configuration entailing a lower availability related risk for the considered host pulp mill is also considered. The threeconsidered integrated systems are: (i) co-gasification of biomass-based pyrolysis oil blended with black liquor for methanol production, (ii) parallel operation of BLG and solid biomass EFG for methanol or ammonia production, and (iii) replacing the bark boiler with solid biomass EFG for methanol or ammonia production. These system solutions establish a combination of material, energy and equipment integration. The main aim of this thesis is to increase the knowledge of the characteristics of entrained flow biomass gasification systems and their opportunities for integration in existing industries for production of green chemicals (methanol and ammonia). An appropriate modelling framework that combines chemical modelling on a high level of detail with holistic industrial site modelling is designed and used to identify and quantify energetic and economic addedvalues for the integrated biorefineries. Mathematical process integration models based on Mixed Integer Linear Programming (MILP) of pulp mills are used to study integration of the biomass gasification systems with the mills. An iterative modelling approach is applied between the process integration model and the detailed biomass gasification models based on Aspen Plus or a Matlab-based thermodynamic equilibrium model. As a complement to themodelling framework, a multi-scale equivalent reactor network (ERN) solid biomass-based EFG model is developed to be able to identify and study influential parameters on the gasifiers’ performance in the Aspen Plus platform. This is approached by considering the effect of mass and heat transfer as well as chemical kinetics. The results show that replacing a recovery or a bark boiler with EFG for green chemicals production improves the overall energy system efficiency and the economic performance,compared to the original operation mode of the mill as well as compared to a stand-alone gasification plant. Significant economy-of-scale effects can be obtained from co-gasification of black liquor and pyrolysis oil. Co-gasification will add extra revenue per produced unit of methanol and reduces the production cost significantly compared to gasification of pure pyrolysis oil. In general, integrated EFG systems producing methanol sold to replace fossilgasoline are shown to constitute attractive investments if the product is exempted from taxes. Ammonia produced via EFG is per unit of produced chemical significantly more capital intense than the corresponding system producing methanol. The economic viability in the considered ammonia configurations is therefore found to be lower compared to methanol.The ERN model is shown to be able to estimate key performance indicators such as carbon conversion, cold gas efficiency, syngas composition, etc. for a real gasification process, showing good agreement with experimental results obtained from a pilot scale gasifier. This simulation tool can in future work be implemented in more global models to study and use to improve the techno-economic performance of EFG-based biorefineries, by quantifying theinfluence of important operational parameters. The main conclusion from this work is that production of green chemicals from biomass EFG integrated with a pulp mill is techno-economically advantageous compared to stand-alonealternatives. It is also concluded that the pulp mill size will be decisive for what integration route is the most favourable. Integration of an individual BLG plant with a pulp mill of maximum size would be the most economically beneficial alternative. However, the possibility to increase the green chemical production from a given black liquor volume improves the viability for integration in smaller mills. Increasing the production volume would therefore result in the highest efficiency and economic benefits given mill sizes up to300 kADt/y. From a resource perspective, this would however lead to an increased demand for biomass import to the mill, and this expansion could be limited by the overall availability of biomass resources.Keywords: Pulp mills, integration, biomass, gasification, green chemicals, methanol, ammonia.

    Fulltekst (pdf)
    FULLTEXT01
  • 32.
    Andersson, Jim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Techno-economic analysis of integrated biomass gasification for green chemical production2013Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Production of renewable motor fuels and green chemicals is important in the development towards a more sustainable society where fossil fuels are replaced. The global annual production of methanol and ammonia from fossil fuels is very large. Alternative production pathways are therefore needed to reduce emission of anthropogenic greenhouse gases and to reduce the fossil fuel dependency. Gasification of lignocellulosic biomass is one promising renewable alternative for that purpose. However, to be able to compete with fossil feedstocks, a highly efficient production of biomass-based products is required to maximize overall process economics and to minimize negative environmental impact. In order to reach reasonable production costs, large production plants will likely be required to obtain favourable economy-of-scale effects.Integrating large scale biofuel or green chemical production processes in existing pulp mills or in other large forest industries may provide large logistical and feedstock handling advantages due to the already existing biomass handling infrastructure. In addition, there are large possibilities to make use of different by-products. In chemical pulp mills, black liquor, a residue from pulp making, provides a good feedstock for the production of chemicals. It has previously been shown that investment in a black liquor gasification plant is advantageous regarding efficiency and economic performance compared to investment in a new recovery boiler. The potential production volume of green chemicals from black liquor is however limited since the availability of black liquor is strongly connected to pulp production. Increased chemical production volumes and thereby potential positive scale effects can be obtained either by adding other types of raw material to the gasification process or by increasing the syngas production by other gasification units operating in parallel. Several publications can be found regarding biomass gasification using one single feedstock and/or gasifier, but only a few consider cogasification of different fuels and dual gasification units. The overall aim of this thesis has therefore been to investigate technoeconomically the integration of biomass gasification systems in existing pulp and paper mills for green chemical production with the focus on creating economy-of-scale effects. The following system configurations were selected: i) a solid biomass gasifier that replaces the bark boiler in a pulp mill for methanol or ammonia production, ii) a solid biomass gasifier operated in parallel with a black liquor gasifier for methanol production, and iii) methanol production from gasification of black liquor blended with biomass-based pyrolysis oil. The main objectives were to find possible and measurable technically and economically added values for different integrated system solutions.The gasifier, the gas conditioning and synthesis were modelled in the commercial software Aspen Plus for material and energy balance calculations. A thermodynamic model developed for gasification of black liquor was used to simulate co-gasification of black liquor blended with pyrolysis oil. The outputs served as inputs for the process integration studies, where models based on Mixed Integer Linear Programming (MILP) were used. An iterative modelling approach between the two models was adopted to ensure that all constraints of the pulp and paper mill as well as for the gasification plant were met. The resulting material and energy balances were used to analyze the different system configurations in terms of overall energy efficiency and process economics. The results show that replacing the recovery or bark boiler with a biomass gasifier for green chemical production improves the overall energy system efficiency and the economic performance compared to the original operation mode of the mill and a non-integrated standalone gasification plant. Significant economy-of-scale effects were obtained when co-gasifying black liquor and pyrolysis oil. This adds extra revenue per produced unit of methanol compared to gasification of pure black liquor, even for pyrolysis oil prices that are considerably higher than projected future commercial scale production costs. Ingeneral, methanol sold to replace fossil gasoline showed good investment opportunities if exempted from taxes. Ammonia produced via gasification of lignocellulosic biomass is per unit of produced chemical significantly more capital intensive than methanol. The investment opportunity of the ammonia configuration is therefore diminished in comparison to methanol production.The main conclusion is that production of green chemicals via biomass gasification integrated in a pulp and paper mill is advantageous compared to stand-alone alternatives. Highest efficiencies and economic benefits are obtained for the systems where co-utilization of upstream (air separation unit) as well as downstream process equipment (gas conditioning units and synthesis loop) is possible.

    Fulltekst (pdf)
    FULLTEXT01
  • 33.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Furusjö, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wetterlund, Elisabeth
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Landälv, Ingvar
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Co-gasification of black liquor and pyrolysis oil: Evaluation of blend ratios and methanol production capacities2016Inngår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 110, s. 240-248Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The main aim of this study is to investigate integrated methanol production via co-gasification of black liquor (BL) and pyrolysis oil (PO), at Swedish pulp mills. The objectives are to evaluate techno-economically different blends ratios for different pulp mill capacities. Furthermore, the future methanol production potential in Sweden and overall system consequences of large-scale implementation of PO/BL co-gasification are also assessed.It is concluded that gasification of pure BL and PO/BL blends up to 50% results in significantly lower production costs than what can be achieved by gasification of unblended PO. Co-gasification with 20–50% oil addition would be the most advantageous solution based on IRR for integrated biofuel plants in small pulp mills (200 kADt/y), whilst pure black liquor gasification (BLG) will be the most advantageous alternative for larger pulp mills. For pulp mill sizes between 300 and 600 kADt/y, it is also concluded that a feasible methanol production can be achieved at a methanol market price below 100 €/MW h, for production capacities ranging between 0.9 and 1.6 TW h/y for pure BLG, and between 1.2 and 6.5 TW h/y for PO/BL co-gasification. This study also shows that by introducing PO/BL co-gasification, fewer pulp mills would need to be converted to biofuel plants than with pure BLG, to meet a certain biofuel demand for a region. Due to the technical as well as organizational complexity of the integration this may prove beneficial, and could also potentially lower the total investment requirement to meet the total biofuel demand in the system. The main conclusion is that PO/BL co-gasification is a technically and economically attractive production route for production biomethanol.

  • 34.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Techno-economic analysis of ammonia production via integrated biomass gasification2014Inngår i: Applied Energy, ISSN 0306-2619, E-ISSN 1872-9118, Vol. 130, nr S1, s. 484-490Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Ammonia (NH3) can be produced by synthesis of nitrogen and hydrogen in the Haber–Bosch process, where the economic challenge is the hydrogen production. Currently, substantial amounts of greenhouse gases are emitted from the ammonia industry since the hydrogen production is almost exclusively based on fossil feedstocks. Hydrogen produced via gasification of lignocellulosic biomass is a more environmentally friendly alternative, but the economic performance is critical. The main objective of this work was to perform a techno-economic evaluation of ammonia production via integrated biomass gasification in an existing pulp and paper mill. The results were compared with a stand-alone production case to find potential technical and economic benefits deriving from the integration. The biomass gasifier and the subsequent NH3 production were modelled using the commercial software Aspen Plus. A process integration model based on Mixed Integer Linear Programming (MILP) was used to analyze the effects on the overall energy system of the pulp mill. Important modelling constraints were to maintain the pulp production and the steam balance of the mill. The results showed that the process economics and energy performance are favourable for the integrated case compared to stand-alone production. The main conclusion was however that a rather high NH3 selling price is required to make both production cases economically feasible.

  • 35.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Techno-economic analysis of ammonia production via integrated biomass gasification2013Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    FULLTEXT01
  • 36.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Furusjö, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Co-gasification of pyrolysis oil and black liquor for methanol production2013Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    FULLTEXT01
  • 37.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Furusjö, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Landälv, Ingvar
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Co-gasification of pyrolysis oil and black liquor for methanol production2015Inngår i: Fuel, ISSN 0016-2361, E-ISSN 1873-7153, Vol. 158, s. 451-459Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    One alternative to reduce the motor fuel production cost and improve the operational flexibility of a black liquor gasification (BLG) plant is to add pyrolysis oil to the black liquor feed and co-gasify the blend. The objective of this study was to investigate techno-economically the possibility to increase methanol production at a pulp mill via co-gasification of pyrolysis oil and black liquor. Gasifying a blend consisting of 50% pyrolysis oil and 50% black liquor on a wet mass basis increases the methanol production by more than 250%, compared to gasifying the available black liquor only. Co-gasification would add extra revenues per produced unit of methanol (IRR > 15%) compared to methanol from unblended BLG (IRR 13%) and be an attractive investment opportunity when the price for pyrolysis oil is less than 70 €/MW h. The economic evaluation was based on a first plant estimate with no investment credit for the recovery boiler and a methanol product value volumetric equivalent to conventional ethanol, both these conditions will not applicable when the technology has been fully commercialized.

  • 38.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Furusjö, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Landälv, Ingvar
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Co-gasification of pyrolysis oil and black liquor: Optimal feedstock mix for different raw material cost scenarios2014Konferansepaper (Fagfellevurdert)
    Fulltekst (pdf)
    FULLTEXT01
  • 39.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Malek, Laura
    Lund Universitet.
    Hulteberg, Christian
    Lund Universitet.
    Pettersson, Karin
    Chalmers University of Technology.
    Wetterlund, Elisabeth
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    System studies on biofuel production via integrated biomass gasification2013Rapport (Fagfellevurdert)
    Fulltekst (pdf)
    FULLTEXT01
  • 40.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundgren, Joakim
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Marklund, Magnus
    Energy Technology Centre, Piteå.
    Methanol production via pressurized entrained flow biomass gasification: Techno-economic comparison of integrated vs. stand-alone production2014Inngår i: Biomass and Bioenergy, ISSN 0961-9534, E-ISSN 1873-2909, Vol. 64, s. 256-268Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The main objective with this work was to investigate techno-economically the opportunity for integrated gasification-based biomass-to-methanol production in an existing chemical pulp and paper mill. Three different system configurations using the pressurized entrained flow biomass gasification (PEBG) technology were studied, one stand-alone plant, one where the bark boiler in the mill was replaced by a PEBG unit and one with a co-integration of a black liquor gasifier operated in parallel with a PEBG unit. The cases were analysed in terms of overall energy efficiency (calculated as electricity-equivalents) and process economics. The economics was assessed under the current as well as possible future energy market conditions. An economic policy support was found to be necessary to make the methanol production competitive under all market scenarios. In a future energy market, integrating a PEBG unit to replace the bark boiler was the most beneficial case from an economic point of view. In this case the methanol production cost was reduced in the range of 11–18 Euro per MWh compared to the stand-alone case. The overall plant efficiency increased approximately 7%-units compared to the original operation of the mill and the non-integrated stand-alone case. In the case with co-integration of the two parallel gasifiers, an equal increase of the system efficiency was achieved, but the economic benefit was not as apparent. Under similar conditions as the current market and when methanol was sold to replace fossil gasoline, co-integration of the two parallel gasifiers was the best alternative based on received IRR.

  • 41.
    Andersson, Jim
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Umeki, Kentaro
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Furusjö, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Kirtania, Kawnish
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Weiland, Fredrik
    SP Energy Technology Center, 941 28 Piteå, Sweden.
    Multiscale Reactor Network Simulation of an Entrained Flow Biomass Gasifier: Model Description and Validation2017Inngår i: Energy Technology, ISSN 2194-4288, Vol. 5, nr 8, s. 1484-1494Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper describes the development of a multiscale equivalent reactor network model for pressurized entrained flow biomass gasification to quantify the effect of operational parameters on the gasification process, including carbon conversion, cold gas efficiency, and syngas methane content. The model, implemented in the commercial software Aspen Plus, includes chemical kinetics as well as heat and mass transfer. Characteristic aspects of the model are the multiscale effect caused by the combination of transport phenomena at particle scale during heating, pyrolysis, and char burnout, as well as the effect of macroscopic gas flow, including gas recirculation. A validation using experimental data from a pilot-scale process shows that the model can provide accurate estimations of carbon conversion, concentrations of main syngas components, and cold gas efficiency over a wide range of oxygen-to-biomass ratios and reactor loads. The syngas methane content was most difficult to estimate accurately owing to the unavailability of accurate kinetic parameters for steam methane reforming.

  • 42.
    Andersson, Linda
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Ek, Kristina
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Kastensson, Åsa
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wårell, Linda
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    The Swedish flex-fuel failure2016Inngår i: BEHAVE 2016, 2016Konferansepaper (Annet vitenskapelig)
    Fulltekst (pdf)
    fulltext
  • 43.
    Andersson, Linda
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Ek, Kristina
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Kastensson, Åsa
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wårell, Linda
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Transition towards sustainable transportation: What determines fuel choice?2020Inngår i: Transport Policy, ISSN 0967-070X, E-ISSN 1879-310X, Vol. 90, s. 31-38Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    For the transport sector to become more sustainable, substantial technological and behavioural changes are required. Increased understanding about household choices related to more green alternatives in transportation is needed in order for policy makers to make efficient policies in the future. The main purpose of this paper is to analyze which factors that determines the fuel choice between ethanol and gasoline for owners of flex-fuel vehicles (FFVs). We evaluate how the self-reported fuel choice is influenced by the relative price, as well as individual differences in norms and perceptions about environmental and quality attributes of ethanol. Data was collected through a survey sent to Swedish FFV owners and is analyzed in a binary choice and a LCM framework. Results show that price, perceptions about quality, age and environmental attitudes influence the self-reported willingness to choose ethanol. Furthermore, results show that preferences are not homogenous, three groups are identified; price conscious respondents, ethanol skeptical respondents and respondents with pronounced environmental concern. However, although the motive for introducing and subsidizing ethanol was to reduce climate and environmental impacts, the group that chooses ethanol based on climate and environmental motives is small. The results further reveal that the debate about motor damages from ethanol have had a long lasting effect on the willingness to choose ethanol. Thus, it is necessary to try to prevent or mitigate concerns regarding e.g. potential technical or ethical issues when promoting future technologies or fuels aimed at a sustainable transportation sector.

  • 44.
    Andersson, Linda
    et al.
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Ek, Kristina
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Kastensson, Åsa
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Wårell, Linda
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Why flex-fuel failed?: A household perspective2016Inngår i: Meeting Sweden's current and future energy challenges, Luleå: Luleå tekniska universitet, 2016, Luleå: Luleå tekniska universitet, 2016Konferansepaper (Annet vitenskapelig)
    Fulltekst (pdf)
    Abstract
    Fulltekst (pdf)
    Presentation
  • 45. Andersson, Magnus
    et al.
    Gebart, Rikard
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundström, Staffan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Långström, R.
    Luleå tekniska universitet.
    Development of guidelines for the vacuum infusion process2000Inngår i: Proceedings of the 8th International Conference on Fibre Reinforced Composites, FRC 2000: Centre for Composite Materials Engineering, University of Newcastle, UK, 13 - 15 September 2000 / [ed] A. G. Gibson, Cambridge: Woodhead Publishing Materials , 2000, s. 113-120Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The current trend towards increased use of vacuum infusion moulding for large surface area parts has increased the interest for an advanced modelling of the process. This paper presents a detailed experimental investigation of laminate thickness and out-of-plane flow front shape during impregnation of high permeability reinforcement on top of a non-crimp fabric reinforcement lay-up. The goal with the experiments is to increase the understanding of the process and to provide accurate data that can later be used for validation of numerical models. The laminate thickness was measured during impregnation with a stereoscopic digital speckle photography system and the flow front shape was determined by tracking of colour marks in the stacking. The laminate lay-ups studied are different combinations of non-crimp fabrics and flow layers while the resin used was a polyester developed specifically for vacuum infusion moulding. Results are presented both for the instantaneous thickness and the flow front shape for several different material combinations. It was found that the skewness of the flow front became more pronounced with increasing number of flow layers when the number of non-crimp fabric layers was kept constant. As a first step towards a complete numerical model of the impregnation process a simplified model for the compressibility and a proven model for permeability was implemented in a commercial CFD package that can handle moving boundaries and moving flow fronts. Only a qualitative comparison with experiments was done but the conclusion was that the overall behaviour of the model was encouraging. A validation of the numerical model based on the measurements in this paper is under development.

  • 46. Andersson, Magnus
    et al.
    Lundström, Staffan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Gebart, Rikard
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Numerical model for vacuum infusion manufacturing of polymer composites2003Inngår i: International journal of numerical methods for heat & fluid flow, ISSN 0961-5539, E-ISSN 1758-6585, Vol. 13, nr 3, s. 383-394Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The focus is set on the development and evaluation of a numerical mgodel describing the impregnation stage of a method to manufacture fibre reinforced polymer composites, namely the vacuum infusion process. Examples of items made with this process are hulls to sailing yachts and containers for the transportation industry. The impregnation is characterised by a full 3D flow in a porous medium having an anisotropic, spatial- and time-dependent permeability. The numerical model has been implemented in a general and commercial computational fluid dynamic software through custom written subroutines that: couple the flow equations to the equations describing the stiffness of the fibre reinforcement; modify the momentum equations to account for the porous medium flow; remesh the computational domain in each time step to account for the deformation by pressure change. The verification of the code showed excellent agreement with analytical solutions and very good agreement with experiments. The numerical model can easily be extended to more complex geometry and to other constitutive equations for the permeability and the compressibility of the reinforcement.

  • 47. Andersson, Magnus
    et al.
    Lundström, Staffan
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Strömningslära och experimentell mekanik.
    Gebart, Rikard
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Långström, R.
    Swedish Institute of Composites, Piteå.
    Flow-enhancing layers in the vacuum infusion process2002Inngår i: Polymer Composites, ISSN 0272-8397, E-ISSN 1548-0569, Vol. 23, nr 5, s. 895-901Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    The current trend towards increased use of vacuum infusion molding for large surface-area parts has increased the interest in an advanced modeling of the process. Because the driving pressure is limited to 1 atmosphere, it is essential to evaluate possible ways to accelerate the impregnation. One way of doing this is to use layers of higher permeability within the reinforcing stack, i.e. flow-enhancing layers. We present an experimental investigation of the flow front shape when using such layers. The through-thickness flow front was observed by making a number of color marks on the glass-mats forming the reinforcing stack, which became visible when the resin reached their position. The in-plane flow front was derived from observations of the uppermost layer. It turned out that existing analytical models agree very well with the experiments if effective permeability data is used, that is, permeability obtained from vacuum infusions. However, the fill-time was nearly twice as long as predicted from permeability data obtained in a stiff tool. This rather large discrepancy may be due to certain features of a flexible mold half and is therefore a topic for further research. The lead-lag to final thickness ratio is dependent on the position of the flow front and ranges form 5 to 10 for the cases tested. Interestingly the lead-lag has a miximum close to the inlet.

  • 48.
    Andersson, Marcus
    et al.
    Luleå tekniska universitet.
    Rönnberg, Sarah
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap.
    Lundmark, Martin
    Larsson, Anders
    Wahlberg, Mats
    Bollen, Math
    Interfering signals and attenuation: potential problems with communication via the power grid2006Inngår i: Proceedings of Nordic Distribution and Asset Management Conference: NORDAC 2006, 2006Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper will give a general overview of the potential problems associated with remote-meter reading via the power grid and describe some of the technologies available. A comparison will be made between the power grid as a communication channel and other, dedicated and shared, channels. Examples will be given of practical cases in which the communication channel does not function in the intended way.

    Fulltekst (pdf)
    fulltext
    Fulltekst (pdf)
    fulltext
  • 49.
    Andrews, David David
    et al.
    European Commission - Joint Research Centre - Institute for Energy and Transport.
    Krook-Riekkola, Anna
    Luleå tekniska universitet, Institutionen för ekonomi, teknik och samhälle, Samhällsvetenskap.
    Tzimas, Evangelos
    European Commission - Joint Research Centre - Institute for Energy and Transport.
    Serpa, Joana
    European Commission - Joint Research Centre - Institute for Energy and Transport.
    Carlsson, Johan
    European Commission - Joint Research Centre - Institute for Energy and Transport.
    Pardo-Garcia, Nico
    European Commission - Joint Research Centre - Institute for Energy and Transport.
    Papaioannou, Ioulia
    European Commission - Joint Research Centre - Institute for Energy and Transport.
    Background Report on EU-27 District Heating and Cooling Potentials, Barriers, Best Practice and Measures of Promotion2012Rapport (Fagfellevurdert)
    Abstract [en]

    The purpose of this report is to provide background information on potentials, barriers, best practices, state of the art and measures of promotion of District Heating and Cooling to aid policy making.

    Fulltekst (pdf)
    FULLTEXT01
  • 50.
    Argyropoulos, Dimitris D. S.
    et al.
    Departments of Chemistry and Forest Biomaterials, North Carolina State University, 431 Dan Allen Drive, Raleigh, North Carolina 27695, USA.
    Crestini, Claudia
    Department of Molecular Sciences and Nanosystems, Ca' Foscari University of Venice, Via Torino 155, 30170 Venezia-Mestre, Italy.
    Dahlstrand, Christian
    Ren Fuel K2B AB, Rapsgatan 25, SE-754 50 Uppsala, Sweden.
    Furusjö, Erik
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Energivetenskap. Division of Bioeconomy and Health, RISE Research Institutes of Sweden, Lindholmspiren 7 A, SE-41756 Göteborg, Sweden.
    Gioia, Claudio
    Department of physics, University of Trento, Via Sommarive 14, 38123 Trento, Italy.
    Jedvert, Kerstin
    Division of Materials and Production, RISE Research Institutes of Sweden, Lindholmspiren 7 A, SE-41756 Göteborg, Sweden.
    Henriksson, Gunnar
    Wallenberg Wood Science Center (WWSC), KTH, Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Hulteberg, Christian
    Department of Chemical Engineering, Faculty of Engineering, Lund University, 221 00 Lund, Sweden.
    Lawoko, Martin
    Wallenberg Wood Science Center (WWSC), KTH, Royal Institute of Technology, 100 44 Stockholm, Sweden.
    Pierrou, Clara
    RenFuel Materials AB, Rapsgatan 25, SE-754 50 Uppsala, Sweden.
    Samec, Joseph S. M.
    Ren Fuel K2B AB, Rapsgatan 25, SE-754 50 Uppsala, Sweden; RenFuel Materials AB, Rapsgatan 25, SE-754 50 Uppsala, Sweden; Department of Organic Chemistry, Stockholm University, Svante Arhenius väg 16 C, 10691 Stockholm, Sweden; Department of Chemistry, Faculty of Science, Chulalongkorn University, Pathumwan, 10330 Bangkok, Thailand.
    Subbotina, Elena
    Center for Green Chemistry and Green Engineering, Yale University, 370 Prospect St, New Haven, CT 06511, USA.
    Wallmo, Henrik
    Valmet AB, Regnbågsgatan 6, 41755 Göteborg, Sweden.
    Wimby, Martin
    Valmet AB, Regnbågsgatan 6, 41755, Göteborg, Sweden.
    Kraft Lignin: A Valuable, Sustainable Resource, Opportunities and Challenges2023Inngår i: ChemSusChem, ISSN 1864-5631, E-ISSN 1864-564X, Vol. 16, nr 23, artikkel-id e202300492Artikkel, forskningsoversikt (Fagfellevurdert)
    Abstract [en]

    Kraft lignin, a by-product from the production of pulp, is currently incinerated in the recovery boiler during the chemical recovery cycle, generating valuable bioenergy and recycling inorganic chemicals to the pulping process operation. Removing lignin from the black liquor or its gasification lowers the recovery boiler load enabling increased pulp production. During the past ten years, lignin separation technologies have emerged and the interest of the research community to valorize this underutilized resource has been invigorated. The aim of this Review is to give (1) a dedicated overview of the kraft process with a focus on the lignin, (2) an overview of applications that are being developed, and (3) a techno-economic and life cycle asseeements of value chains from black liquor to different products. Overall, it is anticipated that this effort will inspire further work for developing and using kraft lignin as a commodity raw material for new applications undeniably promoting pivotal global sustainability concerns.

    Fulltekst (pdf)
    fulltext
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