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| 2. |
- Anheden, Marie
(författare)
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Analysis of gas turbine systems for sustainable energy conversion
- 2000
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Increased energy demands and fear of global warming due tothe emission of greenhouse gases call for development of newefficient power generation systems with low or no carbondioxide(CO2) emissions. In this thesis, two different gasturbine power generation systems, which are designed with theseissues in mind, are theoretically investigated and analyzed.Inthe first gas turbine system, the fuel is combusted using ametal oxide as an oxidant instead of oxygen in the air. Thisprocess is known as Chemical Looping Combustion (CLC). CLC isclaimed to decrease combustion exergy destruction and increasethe power generation efficiency. Another advantage is thepossibility to separate CO2without a costly and energy demanding gasseparation process. The system analysis presented includescomputer-based simulations of CLC gas turbine systems withdifferent metal oxides as oxygen carriers and different fuels.An exergy analysis comparing the exergy destruction of the gasturbine system with CLC and conventional combustion is alsopresented. The results show that it is theoretically possibleto increase the power generation efficiency of a simple gasturbine system by introducing CLC. A combined gas/steam turbinecycle system with CLC is, however, estimated to reach a similarefficiency as the conventional combined cycle system. If thebenefit of easy and energy-efficient CO2separation is accounted for, a CLC combined cyclesystem has a potential to be favorable compared to a combinedcycle system with CO2separation.In the second investigation, a solid, CO2-neutral biomass fuel is used in a small-scaleexternally fired gas turbine system for cogeneration of powerand district heating. Both open and closed gas turbines withdifferent working fluids are simulated and analyzed regardingthermodynamic performance, equipment size, and economics. Theresults show that it is possible to reach high power generationefficiency and total (power-and-heat) efficiency with thesuggested system. The economic analysis reveals that the costof electricity from theEFGT plant is competitive with the moreconventional alternatives for biomass based cogeneration in thesame size range (<10 MWe).Keywords:power generation, Chemical Looping Combustion,CO2separation, oxygen carrier, biomass fuel, closedcycle gas turbine, externally fired gas turbine
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| 5. |
- Anheden, Marie, et al.
(författare)
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The role of intermediate products in biorefinery development : Kraft lignin and pyrolysis oil as intermediates for production of naphtha cracker feed from forest-based raw materials
- 2015
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Ingår i: NWBC 2015. Proceedings of the 6th Nordic Wood Biorefinery Conference held in Helsinki, Finland, 20-22 Oct. 2015. - 9789513883539 ; , s. 210-219
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Konferensbidrag (refereegranskat)abstract
- Research has been undertaken to estimate key performance factors important for development of biomass value chains with intermediate products. In the case selected, the end-product had to be suitable as feed product to a naphtha cracker. Pyrolysis oil and kraft lignin were the investigated intermediates, while yield, cost and carbon dioxide footprint were compared with direct production of bio naphtha from forest residues at the petrochemical plant and fossil naphtha. Three bio-based value chains were evaluated: without intermediate; with pyrolysis oil as intermediate; and with kraft lignin separated from black liquor as intermediate. Innventia AB's simulation model in WinGEMS was used to simulate the hypothetical reference pulp mill and the effects of integration with the lignin removal (LignoBoost) and pyrolysis equipment. It has been concluded that the use of intermediates produced integrated with decentralised local industrial plants could reduce total cost and carbon dioxide emissions of transporting forest based biomass to a centrally located conversion plant. However, the economic benefit was not very large compared with the overall value chain cost to produce the final product. Kraft lignin from pulp production was a very interesting intermediate, particularly in the case of the economic benefit
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| 6. |
- Anheden, Marie, et al.
(författare)
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Value chain for production of bio-oil from kraft lignin for use as bio-jet fuel
- 2017
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Ingår i: The 7th Nordic Wood Biorefinery Conference held in Stockholm, Sweden, 28-30 Mar. 2017. - Stockholm : RISE Bioekonomi. - 9789186018207 ; , s. 104-109
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Konferensbidrag (refereegranskat)abstract
- The LignoJet project aimed to achieve an intermediate lignin-oil product miscible with fossil feedstock and with a significantly reduced oxygen content. A technical concept for production has been studied that involves combined catalysed depolymerisation and hydrodeoxygenation, so called hydrogenolytic depolymerisation, of kraft lignin. Kraft lignin was separated through membrane ultrafiltration from softwood and eucalyptus black liquor followed by precipitation through LignoBoost technology. A difference in lignin properties was observed between ultrafiltration of softwood and eucalyptus black liquor through 15 and 150kDa ceramic membranes. Lignin-oils with similar oxygen content were produced regardless of origin and fractionation technique. A lignin-oil with favourable properties as precursor for refinery integration for jet fuel production as produced in small-scale batch experiments using nickel-based catalyst. Stable pumpable oils with melting point of less than 25-50 deg C and with 20-30% lower oxygen content and aromatic content were obtained that would be suitable as jet fuel precursors. The estimated production cost was found to be competitive with that of other liquid biofuels, while additional revenues could potentially be achieved by also producing chemical and materials from suitable fractions of the lignin-oil.
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| 7. |
- Anheden, Marie, et al.
(författare)
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Value chains for production of Renewable Transportation Fuels Using Intermediates
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- An increased share of renewable transportation fuels requires utilisation of new low-cost sources of bio-based raw materials other than what is currently used in the pulp and paper industry and for power and district heat generation in the bioenergy sector. Currently, proposed raw material includes forest residues (branches and tops), stumps, waste round wood and different by-products from pulp and pa-per industry and sawmills. Of these, forest residues and stumps have, by far, the largest potential for increased utilisation. However, these types of raw materials are often voluminous and heterogeneous and are difficult to handle in existing refineries for production of transportation fuels. The cost of transporting this type of raw material over large distances in order to supply a larger plant is often said to be high. This report includes an analysis of the possible advantages and disadvantages of transform-ing forest-based biomass to an intermediate product with a higher energy density that is more homo-geneous and easier to handle during transport and during final conversion to transportation fuel.Two value chains are investigated as case studies a) bio-SNG production using forest residues, bark and sawdust as raw material and b) bio-oil production from forest residues, lignin in black liquor and tall oil, which can be upgraded to transportation fuels at a refinery. In the study we have assumed that the conversion of the original biomass to an intermediate product mainly takes place at a pulp mill. The intermediate conversion technologies included for value chain a) are drying and pelletizing and for value chain b) pyrolysis and distillation. The final conversion to end product bio-SNG takes place in connection to a district heating system, and the final deoxygenation and upgrading of bio-oil to hydrodeoxygenated (HDO) oil takes place at an oil refinery. The value chains with intermediates are compared with value chains without intermediates where the entire conversion process to final product is located in connection to a district heating system in value chain a) and at a stand-alone plant near to a refinery in value chain b). The value chains are studied from a well-to-gate perspective, from extrac-tion of the forest biomass to produced bio-SNG/HDO bio-oil. A direct comparison between value chains for bio-SNG and bio-oil production should be avoided. They are based on different reference data that are not synchronized. A direct comparison between the chains should in addition be done in a well-to-wheel perspective.The results show that the initial hypothesis that local production of a more energy dense intermediate would reduce transportation costs could not be verified. The reason is primarily the introduction of a second transport step to transport the intermediate to the final conversion site in addition to the transport of the raw material. The transport costs are associated with relatively high fixed cost espe-cially for ship and train transport, so the introduction of a second relatively high fixed transport cost of the intermediate has a dominating effect. Further, it can be concluded that the transport cost make up a relatively small share of the total production cost of the final product, in the order of 10%, and in a few cases up to 20%. There is therefore a relatively small difference in total specific production cost for the final product between value chains with and without intermediates considering the level of uncer-tainty in the input data and the assumptions behind the scenarios studied.Summarizing, the results indicate that the production costs are highly sensitive to the economies of scale, oxygen content in the bio-crude oil and raw material costs (forest residues price or electricity price in the case where lignin is used as raw material). Transportation costs have, comparatively, a little effect in the total production cost.
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| 8. |
- Carvalho, Lara, et al.
(författare)
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Techno-economic assessment of catalytic gasification of biomass powders for methanol production
- 2017
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Ingår i: Bioresource Technology. - : Elsevier BV. - 0960-8524 .- 1873-2976. ; 237, s. 167-177
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Tidskriftsartikel (refereegranskat)abstract
- This study evaluated the techno-economic performance and potential benefits of methanol production through catalytic gasification of forest residues and lignin. The results showed that while catalytic gasification enables increased cold gas efficiencies and methanol yields compared to non-catalytic gasification, the additional pre-treatment energy and loss of electricity production result in small or no system efficiency improvements. The resulting required methanol selling prices (90–130 €/MWh) are comparable with production costs for other biofuels. It is concluded that catalytic gasification of forest residues can be an attractive option as it provides operational advantages at production costs comparable to non-catalytic gasification. The addition of lignin would require lignin costs below 25 €/MWh to be economically beneficial.
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| 9. |
- Eide, Lars, et al.
(författare)
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Novel Capture Processes
- 2005
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Ingår i: Oil and Gas Science and Technology. ; 60:3, s. 497-508
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Tidskriftsartikel (refereegranskat)
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| 10. |
- Fahnestock, Jesse, 1974-, et al.
(författare)
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RISEnergy: Roadmaps for energy innovation in Sweden through 2030
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- RISE Research Institutes of Sweden is a group of research and technology organisations. RISE is a leading innovation partner working global cooperation with academia, enterprise and society to create value, growth and competitiveness through research excellence and innovation.In the area of Energy, RISE has developed innovation Roadmaps covering:Energy Efficient TransportElectric Power SystemEnergy Efficient and Smart BuildingsSustainable Thermal ProcessesEfficient Energy Use in IndustryDecarbonisation of Basic IndustriesThese Roadmaps describe development pathways for technologies, non-technical elements (market design, user behaviours, policies, etc.) and key actors that deliver on a plausible, desirable vision for each respective innovation area in 2030. These Roadmaps are intended to support RISE’s strategic planning and development, but should be relevant reading for anyone interested in energy innovation in Sweden.
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