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- Johnsson, Filip, 1960, et al.
(författare)
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Optical and momentum probe measurements in a CFB boiler
- 1996
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Ingår i: Proc of the 5th International Conference on Circulating Fluidized Bed. ; , s. 652-657
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Konferensbidrag (refereegranskat)abstract
- Methods for the characterization of the two-phase flow in the transport zone of circulating fluidized bed (CFB) boilers are discussed based on measurements of fluctuations in local solids concentration and momentum flux using an optimum probe and a momentum probe. Both probes were designed to withstand the environment inside a furnace during combustion. The dynamic information on the flow obtained by the two probes was in agreement. The time-resolved measurements in the core region as well as in the wall layer by continuous increases and decreases in solids concentration and momentum flow from a base level at low solids concentration.
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| 3. |
- Kjärstad, Jan, 1956, et al.
(författare)
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Transforming the energy system in Västra Götaland and Halland – linking short term actions to long term goals
- 2015
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This study analyzes pathways to meet EU, national and regional targets for CO2 emissions, energy efficiency and penetration of renewable energy in the Swedish part of the Kattegat-Skagerrak region (KASK-SE), i.e. more specifically in the counties of Västra Götaland (VGR) and Halland. Special focus is placed on four areas: The potential for energy savings in the building sector, energy savings and fuel shifting in the energy intensive industry, large-scale deployment of renewables in the electricity generation sector and greenhouse gas emission reductions in the transport sector. The energy savings are through the implementation of different energy efficiency measures.
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| 5. |
- Ajdari, Sima, 1985, et al.
(författare)
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Modeling the Nitrogen and Sulfur Chemistry in Pressurized Flue Gas Systems
- 2015
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 1520-5045 .- 0888-5885. ; 54:4, s. 1216-1227
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Tidskriftsartikel (refereegranskat)abstract
- A rate-based model is developed to elucidate the chemistry behind the simultaneous absorption of NOx and SOx under pressurized conditions (pressures up to 30 bar) that are applicable to the flue gases obtained from CO2 capture systems. The studied flue gas conditions are relevant to oxy-fuel and chemical-looping combustion systems. The kinetics of the reactions implemented in the model is based on a thorough review of the literature. The chemistry of nitrogen, sulfur, and N-S interactions are evaluated in detail, and the most important reaction pathways are discussed. The effects of pH, pressure, and flue-gas composition on the liquid-phase chemistry are also examined and discussed. Simulations that use existing kinetic data reveal that the pH level has a strong influence on the reaction pathway that is followed and the types of products that are formed in the liquid phase. In addition, the pressure level and the presence of NOx significantly affect the removal of SO2 from the flue gas.
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| 9. |
- Ajdari, Sima, 1985, et al.
(författare)
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Reduced Mechanism for Nitrogen and Sulfur Chemistry in Pressurized Flue Gas Systems
- 2016
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Ingår i: Industrial & Engineering Chemistry Research. - : American Chemical Society (ACS). - 1520-5045 .- 0888-5885. ; 55:19, s. 5514-5525
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Tidskriftsartikel (refereegranskat)abstract
- The gas- and liquid-phase chemistry of nitrogen and sulfur species under pressurized conditions is of high importance to the design and performance of the pressurized flue gas systems in carbon capture and storage (CCS) schemes. Yet, the available description of this chemistry is complex and difficult to apply in design studies for removal of NOx and SOx during the compression. This work proposes a reduced mechanism for engineering calculations of pressurized flue gas systems, a mechanism that is able to describe the relevant gas and liquid-phase chemistry as well as the S/N-product distribution. The reduced mechanism is derived by identifying the rate-limiting reactions using sensitivity analysis. The performance of the mechanism subsets are compared with results of a detailed mechanism. The identified rate-limiting reactions for the formation of key products form the basis for two different types of reduced mechanisms. The sets include one general reduced mechanism (valid for all pH conditions) and sets of pH-specific mechanisms. The general reduced mechanism and the pH-specific mechanisms perform satisfactorily compared to the detailed mechanism under different pH conditions. The results show that depending on the purpose of the modeling, whether it is to predict the pollutant removal (where sulfurous acid and nitrogen acids are mainly important) or capture the liquid composition, for which the N-S chemistry products are also important, different levels of simplification can be made. The number of reactions is reduced from 34 reactions (39 species) in the detailed mechanism to 12 reactions (20 species) in the general reduced mechanism and 7-8 (14-17 species) in the pH-specific mechanisms.
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| 10. |
- Alamia, Alberto, 1984, et al.
(författare)
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Well-to-wheel analysis of bio-methane via gasification, in heavy duty engines within the transport sector of the European Union
- 2016
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Ingår i: Applied Energy. - : Elsevier BV. - 1872-9118 .- 0306-2619. ; 170, s. 445-454
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Tidskriftsartikel (refereegranskat)abstract
- Bio-methane from biomass gasification (bio-methane) is expected to play a major role as a biofuel in the heavy transport sector, since the production process has reached the technical maturity required for large-scale exploitation, and the fact that bio-methane can be distributed through the compressed natural gas (CNG) and liquefied natural gas (LNG) supply chains. Assuming that the burning of biomass is climate-neutral, we compared the well-to-wheel (WtW) emissions from the use of bio-methane in heavy duty engines with those from currently used fossil alternatives: CNG, LNG, and diesel. The well-to-tank (WtT) analysis of bio-methane is based on the case study of the new GoBiGas plant in Gothenburg (Sweden), which is the largest bio-methane plant in the world currently in operation. Finally, tank-to-wheel (TtW) section compares three different state-of-the-art heavy duty gas engines: a spark-ignited (SI) gas engine; a dual fuel (DF) engine; and a high-pressure direct injection (HPDI) engine.The WtT emissions for compressed bio-methane (bio-CNG) and liquefies bio-methane (bio-LNG) were estimated at 21.5 [gCO2e/MJbioCNG] and 26.2 [gCO2e/MJbioLNG]. As compared to diesel the WtW emissions from bio-methane were reduced by 60-67%, 43-47%, and 64% when used in SI, DF, and HPDI engines, respectively. HPDI and DF are the most efficient technologies for the utilization of biomass, reducing emissions by 39 gCO2e and 33-36 gCO2e per MJ of biomass, respectively, compared with the diesel case, whereas the SI engine gave an emissions saving of 29-31 gCO2e.
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