| 11. |
- Landälv, Ingvar, et al.
(författare)
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Two years experience of the BioDME project : A complete wood to wheel concept
- 2014
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Ingår i: Environmental Progress & Sustainable Energy. - : Wiley. - 1944-7442 .- 1944-7450. ; 33:3, s. 744-750
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Tidskriftsartikel (refereegranskat)abstract
- Dimethyl ether (DME), is an excellent diesel fuel that can be produced through gasification from multiple feedstocks. One particularly interesting renewable feedstock is the energy rich by-product from the pulping process called black liquor (BL). The concept of utilizing BL as gasifier feed, converting it via syngas to DME and then compensating the withdrawal of BL energy from the pulp mill by supplying biomass to a conventional combined heat and power plant, is estimated to be one of the most efficient conversion concepts of biomass to a renewable fuel on a well-to-wheel basis. This concept has been demonstrated by the four-year BioDME project, including field tests of DME-fueled heavy-duty trucks that are operated commercially. Up till the summer of 2013 more than 500 tons of BioDME has been produced and distributed to 10 HD trucks, which in total has run more than 1 million km in commercial service
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| 12. |
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| 13. |
- Molinder, Roger, et al.
(författare)
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Characterization and cleanup of wastewater from pressurized entrained flow biomass gasification
- 2014
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Ingår i: ACS Sustainable Chemistry and Engineering. - : American Chemical Society (ACS). - 2168-0485. ; 2:8, s. 2063-2069
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Tidskriftsartikel (refereegranskat)abstract
- Wastewater produced during pressurized entrained flow biomass gasification (PEBG) was characterized and cleaned in order to raise the technology readiness level of the PEBG concept. Scanning electron microscopy (SEM) coupled with energy dispersive spectroscopy (EDS) and thermogravimetric analysis (TGA) were used to study material found in the water. The material was removed using filtration and the concentration of dissolved organic carbon (DOC), polyaromatic hydrocarbons (PAHs) and metals in filtered water was studied using standardized methods. Water was sampled during operation at three oxygen equivalence ratios (λ) and the results were compared to concentrations of gaseous hydrocarbons in the syngas. As λ increased, the amount of soot in the wastewater and the amount of soot precursors in the syngas was reduced. As a result the concentration of particles in the water was reduced and their composition shifted toward a higher percentage of inorganics (ash). PAH concentration trends in the water and in the syngas correlated and dissolved organic material in the water was reduced with increased λ. A particle removal efficiency of 98-99% was achieved using sedimentation and filtration while the DOC was reduced from ≈2.5 mg L-1 to below detection limit using granular activated carbon (GAC). © 2014 American Chemical Society.
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| 14. |
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| 15. |
- Risberg, Mikael, et al.
(författare)
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Influence from fuel type on the performance of an air-blown cyclone gasifier
- 2014
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 116, s. 751-759
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Tidskriftsartikel (refereegranskat)abstract
- Entrained flow gasification of biomass using the cyclone principle has been proposed in combination with a gas engine as a method for combined heat and power production in small to medium scale (<20 MW). This type of gasifier also has the potential to operate using ash rich fuels since the reactor temperature is lower than the ash melting temperature and the ash can be separated after being collected at the bottom of the cyclone. The purpose of this work was to assess the fuel flexibility of cyclone gasification by performing tests with five different types of fuels; torrefied spruce, peat, rice husk, bark and wood. All of the fuels were dried to below 15% moisture content and milled to a powder with a maximum particle size of around 1 mm. The experiments were carried out in a 500 kWth pilot gasifier with a 3-step gas cleaning process consisting of a multi-cyclone for removal of coarse particles, a bio-scrubber for tar removal and a wet electrostatic precipitator for removal of fine particles and droplets from the oil scrubber (aerosols). The lower heating value (LHV) of the clean producer gas was 4.09, 4.54, 4.84 and 4.57 MJ/Nm3 for peat, rice husk, bark and wood, respectively, at a fuel load of 400 kW and an equivalence ratio of 0.27. Torrefied fuel was gasified at an equivalence ratio of 0.2 which resulted in a LHV of 5.75 MJ/Nm3 which can be compared to 5.50 MJ/Nm3 for wood powder that was gasified at the same equivalence ratio. A particle sampling system was designed in order to collect ultrafine particles upstream and downstream the gasifier cleaning device. The results revealed that the gas cleaning successfully removed >99.9% of the particulate matter smaller than 1 μm.
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| 16. |
- Rownaghi, Ali, et al.
(författare)
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Yield of dimethyl ether and gasoline as a function of size of ZSM-5 crystals
- 2011
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Ingår i: 2010 AIChE annual meeting conference proceedings. - New York : American Institute of Chemical Engineers. - 9780816910656
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Konferensbidrag (refereegranskat)abstract
- In this work we have studied different acidic zeolitic solid catalysts ZSM-5 with different crystal size, measuring their physical-chemical properties and correlating this with the activity, selectivity at different process condition during the conversion of methanol to dimethyl ether (DME) and gasoline boiling range hydrocarbons. The catalytic properties of these catalysts depended mainly on the crystal size and surface properties. Methanol feed in the DME and gasoline process is derived from black liquor-based syngas. The methanol to DME and gasoline process involves the conversion of black liquor syngas to crude methanol and methanol to DME and gasoline
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| 17. |
- Sjöberg, Erik, et al.
(författare)
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Separation of CO2 from black liquor derived syngas using an MFI membrane
- 2013
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Ingår i: Journal of Membrane Science. - : Elsevier BV. - 0376-7388 .- 1873-3123. ; 443, s. 131-137
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Tidskriftsartikel (refereegranskat)abstract
- Membrane separation of CO2 from synthesis gas could be an energy efficient and simple alternative to other separation techniques. In this work, a membrane comprised of an about 0.7μm thick MFI film on a graded alumina support was used to separate CO2 from synthesis gas produced by pilot scale gasification of black liquor. The separation of CO2 from the synthesis gas was carried out at a feed pressure of 2.25MPa, a permeate pressure of 0.3MPa and room temperature. In the beginning of the experiment, when the H2S concentration in the feed was 0.5% and the concentration of water in the feed was 0.07%, a CO2/H2 separation factor of 10.4 and a CO2 flux of 67.0kgm-2h-1 were observed. However, as the H2S concentration in the feed to the membrane increased to 1.7%, the CO2/H2 separation factor and the CO2 flux decreased to 5 and 61.4kgm-2h-1, respectively. The results suggest that MFI membranes are promising candidates for the separation of CO2 from synthesis gas.
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| 18. |
- Weiland, Fredrik, et al.
(författare)
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Pressurized oxygen blown entrained-flow gasification of wood powder
- 2013
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 27:2, s. 932-941
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Tidskriftsartikel (refereegranskat)abstract
- In the present study, an oxygen blown pilot scale pressurized entrained-flow biomass gasification plant (PEBG, 1 MWth) was designed, constructed, and operated. This Article provides a detailed description of the pilot plant and results from gasification experiments with stem wood biomass made from pine and spruce. The focus was to evaluate the performance of the gasifier with respect to syngas quality and mass and energy balance. The gasifier was operated at an elevated pressure of 2 bar(a) and at an oxygen equivalence ratio (λ) between 0.43 and 0.50. The resulting process temperatures in the hot part of the gasifier were in the range of 1100-1300 °C during the experiments. As expected, a higher λ results in a higher process temperature. The syngas concentrations (dry and N 2 free) during the experiments were 25-28 mol % for H2, 47-49 mol % for CO, 20-24 mol % for CO2, and 1-2 mol % for CH 4. The dry syngas N2 content was varied between 18 and 25 mol % depending on the operating conditions of the gasifier. The syngas H 2/CO ratio was 0.54-0.57. The gasifier cold gas efficiency (CGE) was approximately 70% for the experimental campaigns performed in this study. The synthesis gas produced by the PEBG has potential for further upgrading to renewable products, for example, chemicals or biofuels, because the performance of the gasifier is close to that of other relevant gasifiers.
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| 19. |
- Wiinikka, Henrik, et al.
(författare)
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Characterisation of submicron particles produced during oxygen blown entrained flow gasification of biomass
- 2014
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Ingår i: Combustion and Flame. - : Elsevier BV. - 0010-2180 .- 1556-2921. ; 161:7, s. 1923-1934
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Tidskriftsartikel (refereegranskat)abstract
- In this paper submicron particles sampled after the quench during 200kW, 2bar(a) pressurised, oxygen blown gasification of three biomass fuels, pure stem wood of pine and spruce, bark from spruce and a bark mixture, have been characterised with respect to particle size distribution with a low pressure cascade impactor. The particles were also characterised for morphology and elemental composition by a combination of scanning electron microscopy/energy dispersive spectroscopy (SEM/EDS) and high resolution transmission electron microscopy/energy dispersive spectroscopy/selected area electron diffraction pattern (HRTEM/EDS/SAED) techniques. The resulting particle concentration in the syngas after the quench varied between 46 and 289mg/Nm3 consisting of both carbon and easily volatile ash forming element significantly depending on the fuel ash content. Several different types of particles could be identified from classic soot particles to pure metallic zinc particles depending on the individual particle relation of carbon and ash forming elements. The results also indicate that ash forming elements and especially zinc interacts in the soot formation process creating a particle with shape and microstructure significantly different from a classical soot particle.
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| 20. |
- Öhrman, Olov, et al.
(författare)
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Analysis of trace components in synthesis gas generated by black liquor gasification
- 2012
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 102, s. 173-179
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Tidskriftsartikel (refereegranskat)abstract
- The only pressurized black liquor gasifier currently in operation is located in Sweden. The composition of the main components in the gas has been reported previously. The main components are H 2, CO, CO 2, N 2, CH 4, and H 2S. In the present work, trace components in the gas have been characterized and the results are hereby reported for the first time. Samples were taken at two occasions during a one year period. The benzene concentration in the gas varied only slightly and the average concentration was 158 ppm. Benzene is formed by thermal cracking of the biomass. The COS concentration varied substantially and the average concentration was 47 ppm. The variations may be related to how the quench is operated. A few ppm of C 2-hydrocarbons were also observed in the gas and the variation was probably a result of varying oxygen to black liquor ratio. No tars were observed in the gas. However, tar compounds, such as phenanthrene, pyrene, fluoranthene and fluorene were detected in deposits found on the pipe walls after the gas cooler. The concentration of particles in the synthesis gas was very low; <0.1 mg/N m 3, which is comparable to the particulate matter in ambient air. Submicron particles were comprised of elements such as C, O, Na, Si, S, Cl, K, and Ca, and these particles probably originated from the black liquor. Larger particles were comprised mainly of Fe, S and Ni and these particles probably resulted from corrosion of steel in the plant pipe-work. In summary, the concentrations of trace components and particles in the gas are quite low.
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