| 1. |
- Carvalho, Lara, et al.
(författare)
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Alkali enhanced biomass gasification with in situ S capture and a novel syngas cleaning : Part 2: Techno-economic analysis
- 2018
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Ingår i: Energy. - : Elsevier. - 0360-5442 .- 1873-6785. ; 165:Part B, s. 471-482
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Tidskriftsartikel (refereegranskat)abstract
- Previous research has shown that alkali addition has operational advantages in entrained flow biomass gasification and allows for capture of up to 90% of the biomass sulfur in the slag phase. The resultant low-sulfur content syngas can create new possibilities for syngas cleaning processes. The aim was to assess the techno-economic performance of biofuel production via gasification of alkali impregnated biomass using a novel gas cleaning systemcomprised of (i) entrained flow catalytic gasification with in situ sulfur removal, (ii) further sulfur removal using a zinc bed, (iii) tar removal using a carbon filter, and (iv) CO2 reductionwith zeolite membranes, in comparison to the expensive acid gas removal system (Rectisol technology). The results show that alkali impregnation increases methanol productionallowing for selling prices similar to biofuel production from non-impregnated biomass. It was concluded that the methanol production using the novel cleaning system is comparable to the Rectisol technology in terms of energy efficiency, while showing an economic advantagederived from a methanol selling price reduction of 2–6 €/MWh. The results showed a high level of robustness to changes related to prices and operation. Methanol selling prices could be further reduced by choosing low sulfur content feedstocks.
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| 2. |
- Johansson, Ann-Christine, et al.
(författare)
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Characterization of pyrolysis products produced from different Nordic biomass types in a cyclone pilot plant
- 2016
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Ingår i: Fuel processing technology. - : Elsevier. - 0378-3820 .- 1873-7188. ; 146, s. 9-19
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Tidskriftsartikel (refereegranskat)abstract
- Pyrolysis is a promising thermochemical technology for converting biomass to energy, chemicals and/or fuels. The objective of the present paper was to characterize fast pyrolysis products and to study pyrolysis oil fractionation. The products were obtained from different Nordic forest and agricultural feedstocks in a pilot scale cyclone pyrolysis plant at three different reactor temperatures. The results show that the main elements (C, H and O) and chemical compositions of the products produced from stem wood, willow, forest residue and reed canary grass are in general terms rather similar, while the products obtained from bark differ to some extent. The oil produced from bark had a higher H/Ceff ratio and heating value which can be correlated to a higher amount of pyrolytic lignin and extractives when compared with oils produced from the other feedstocks. Regardless of the original feedstock, the composition of the different pyrolysis oil fractions (condensed and aerosol) differs significantly from each other. However this opens up the possibility to use specifically selected fractions in targeted applications. An increased reactor temperature generally results in a higher amount of water and water insoluble material, primarily as small lignin derived oligomers, in the produced oil.
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| 3. |
- Johansson, Ann-Christine, et al.
(författare)
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Co-pyrolysis of woody biomass and plastic waste in both analytical and pilot scale
- 2018
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 134, s. 102-1113
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Tidskriftsartikel (refereegranskat)abstract
- Earlier studies show that co-pyrolysis of biomass and plastics can improve the quantity and quality of the produced pyrolysis oil compared to pyrolysis of the separate feedstocks. In this work three relevant plastic wastes; paper reject, shredder light fraction and cable plastics; were evaluated together with woody biomass (stem wood from spruce and pine) using analytical pyrolysis, Py-GC–MS/FID. One verification experiment was also conducted in a cyclone pyrolyser pilot plant at industrially relevant conditions. The addition of plastic waste to woody biomass pyrolysis was found to significantly affect the composition and properties of the produced pyrolysis products. In analytical pyrolysis experiments, positive synergetic effects were observed in the co-pyrolysis of paper reject and cable plastics together with the stem wood. The yield of reactive oxygenated compounds (ketones, aldehydes and acids) was suppressed while more stable alcohols and esters were promoted. The formation of hydrocarbons was also promoted in the co-pyrolysis of plastics from paper reject and stem wood. The results from the analytical pyrolysis were partly verified in the pilot scale experiment by co-pyrolysing stem wood and paper reject. However, the co-pyrolysis also affected other parameters that cannot be detected in analytical pyrolysis such as higher acidity and viscosity of the oil which highlights the need for undertaking experiments at different scales. The product yields in pilot scale were about the same for the co-pyrolysis case as for pure stem wood. However, a high volatile content of the solid product indicated that the process conditions can be further optimized for co-pyrolysing cases.
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| 4. |
- Johansson, Ann-Christine, et al.
(författare)
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Experiences of pilot scale cyclone pyrolysis
- 2017
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Ingår i: European Biomass Conf. Exhib. Proc.. - : ETA-Florence Renewable Energies. ; , s. 952-955
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Konferensbidrag (refereegranskat)abstract
- Fast pyrolysis is a promising thermochemical technology for converting biomass to energy, chemicals, and fuels. At RISE ETC, an industrially relevant pyrolysis pilot plant has been designed, constructed, and operated since 2011. The pilot plant is based on an externally heated cyclone reactor where both the pyrolysis reaction and the separation of products take place. The reactor design has shown to be beneficial since it produces oil with relatively low concentrations of inorganics. Pyrolysis of different Nordic biomasses, both forestry and agricultural, have been studied using the pilot plant and the results indicate that it is especially suitable for low grade fuels. The oil is collected in two separate steps, and the received two oil fractions have different chemical and physical properties, which opens up the possibility to use selected fractions in targeted applications. Oil fractionation has also been studied further in a separate fractional condensation system and the results show that it is possible to separate larger energy-rich lignin-derived material; medium-sized; and light water soluble compounds already in the oil collection step. The pilot plant has worked as a platform for pyrolysis research and for building up competence in the pyrolysis area.
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| 5. |
- Johansson, Ann-Christine, et al.
(författare)
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Fractional condensation of pyrolysis vapors produced from Nordic feedstocks in cyclone pyrolysis
- 2017
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 123, s. 244-254
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Tidskriftsartikel (refereegranskat)abstract
- Pyrolysis oil is a complex mixture of different chemical compounds with a wide range of molecular weights and boiling points. Due to its complexity, an efficient fractionation of the oil may be a more promising approach of producing liquid fuels and chemicals than treating the whole oil. In this work a sampling system based on fractional condensation was attached to a cyclone pyrolysis pilot plant to enable separation of the produced pyrolysis vapors into five oil fractions. The sampling system was composed of cyclonic condensers and coalescing filters arranged in series. The objective was to characterize the oil fractions produced from three different Nordic feedstocks and suggest possible applications. The oil fractions were thoroughly characterized using several analytical techniques including water content; elemental composition; heating value, and chemical compound group analysis using solvent fractionation, quantitative 13C NMR and 1H NMR and GC x GC − TOFMS. The results show that the oil fractions significantly differ from each other both in chemical and physical properties. The first fractions and the fraction composed of aerosols were highly viscous and contained larger energy-rich compounds of mainly lignin-derived material. The middle fraction contained medium-size compounds with relatively high concentration of water, sugars, alcohols, hydrocarbonyls and acids and finally the last fraction contained smaller molecules such as water, aldehydes, ketones and acids. However, the properties of the respective fractions seem independent on the studied feedstock types, i.e. the respective fractions produced from different feedstock are rather similar. This promotes the possibility to vary the feedstock depending on availability while retaining the oil properties. Possible applications of the five fractions vary from oil for combustion and extraction of the pyrolytic lignin in the early fractions to extraction of sugars from the early and middle fractions, and extraction of acids and aldehydes in the later fractions.
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| 6. |
- Leijenhorst, Evert J., et al.
(författare)
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Entrained flow gasification of straw- and wood-derived pyrolysis oil in a pressurized oxygen blown gasifier
- 2015
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 79, s. 166-176
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Tidskriftsartikel (refereegranskat)abstract
- Fast pyrolysis oil can be used as a feedstock for syngas production. This approach can have certain advantages over direct biomass gasification. Pilot scale tests were performed to investigate the route from biomass via fast pyrolysis and entrained flow gasification to syngas. Wheat straw and clean pine wood were used as feedstocks; both were converted into homogeneous pyrolysis oils with very similar properties using in-situ water removal. These pyrolysis oils were subsequently gasified in a pressurized, oxygen blown entrained flow gasifier using a thermal load of 0.4 MW. At a pressure of 0.4 MPa and a lambda value of 0.4, temperatures around 1250 °C were obtained. Syngas volume fractions of 46% CO, 30% H2 and 23% CO2 were obtained for both pyrolysis oils. 2% of CH4 remained in the product gas, along with 0.1% of both C2H2 and C2H4. Minor quantities of H2S (3 vs. 23) cm3 m−3, COS (22 vs. 94) cm3 m−3 and benzene (310 vs. 532) cm3 m−3 were measured for wood- and straw derived pyrolysis oils respectively. A continuous 2-day gasification run with wood derived pyrolysis oil demonstrated full steady state operation. The experimental results show that pyrolysis oils from different biomass feedstocks can be processed in the same gasifier, and issues with ash composition and melting behaviour of the feedstocks are avoided by applying fast pyrolysis pre-treatment.
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| 7. |
- Lestander, Torbjörn, et al.
(författare)
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Characterization of fast pyrolysis bio-oil properties by near-infrared spectroscopic data
- 2018
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Ingår i: Journal of Analytical and Applied Pyrolysis. - : Elsevier BV. - 0165-2370 .- 1873-250X. ; 133, s. 9-15
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Tidskriftsartikel (refereegranskat)abstract
- Pyrolysis transforms bulky and heterogeneous lignocellulosic biomass into more easily-handled oils that can be upgraded into bio-based transportation fuels. Existing systems for monitoring pyrolysis processes and characterizing their products rely on slow and time-consuming wet chemical analyses. On-line near-infrared (NIR) spectroscopy could potentially replace such analyses, providing real-time data and reducing costs. To test the usefulness of NIR methods in characterizing pyrolysis oils and processes, biomass from conifers, Salix, and reed canary grass was milled and pyrolyzed at 675, 750, and 775 °C. Two separate pyrolytic fractions (aerosol and condensed) were produced in each experiment, and NIR spectra were collected for each fraction. Multivariate modelling of the resulting data clearly showed that the samples’ NIR spectra could be used to accurately predict important properties of the pyrolysis oils such as their energy values, main organic element (C, H and O) contents, and water content. The spectra also contained predictive information on the samples’ origins, fraction, and temperature treatment, demonstrating the potential of on-line NIR techniques for monitoring pyrolytic production processes and characterizing important properties of pyrolytic oils from lignocellulosic biomass.
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| 8. |
- Sandström, Linda, et al.
(författare)
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Pyrolysis of Nordic biomass types in a cyclone pilot plant — Mass balances and yields
- 2016
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Ingår i: Fuel processing technology. - : Elsevier BV. - 0378-3820 .- 1873-7188. ; 152, s. 274-284
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Tidskriftsartikel (refereegranskat)abstract
- Fast pyrolysis of biomass results in a renewable product usually denoted pyrolysis oil or bio-oil, which has been suggested to be used as a direct substitute for fuel oil or as a feedstock for production of transportation fuels and/or chemicals. In the present work, fast pyrolysis of stem wood (originated from pine and spruce), willow, reed canary grass, brown forest residue and bark has been performed in a pilot scale cyclone reactor. The experiments were based on a biomass feeding rate of 20 kg/h at three different reactor temperatures. At the reference condition, pyrolysis of stem wood, willow, reed canary grass, and forest residue resulted in organic liquid yields in the range of 41 to 45% w/w, while pyrolysis of bark resulted in lower organic liquid yields. Two fractions of pyrolysis oil were obtained, denoted as the condensed and the aerosol fraction. Most of the water soluble molecules were collected in the condensed fraction, whereas the yield of water insoluble, heavy lignin molecules was higher in the aerosol fraction. Based on the results of the present work, willow, reed canary grass and forest residue are considered as promising raw materials for production of pyrolysis oil in a cyclone reactor.
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| 9. |
- Sjöblom, Magnus, et al.
(författare)
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In Situ Biocatalytic Synthesis of Butyl Butyrate in Diesel and Engine Evaluations
- 2017
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Ingår i: ChemCatChem. - : Wiley. - 1867-3880 .- 1867-3899. ; 9:24, s. 4529-4537
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Tidskriftsartikel (refereegranskat)abstract
- Blending petroleum fuels with biofuels is likely to become increasingly important over the years to come. Butyl butyrate has promising characteristics as a blend component in diesel and can be synthesized by lipase-catalyzed esterification of 1-butanol and butyric acid, which both can be derived from fermentation technologies. In the current study, the enzyme load and reaction temperature were optimized for the production of butyl butyrate with Novozyme 435 (immobilized Candida antarctica lipase B) directly in diesel at a substrate concentration of 1 m using a molar ratio of 1:1 between n-butanol and butyric acid. Optimum conditions were found by using a central composite design at an enzyme load of 12 % of substrate weight and a temperature of 57 °C, giving 90 % yield conversion in 30 min, corresponding to a butyl butyrate productivity of 1.8 mol L−1 h−1. Diesel blended with 5, 10, and 30 % butyl butyrate was tested in a heavy-duty diesel engine under two load cases. The ignition properties of the blended fuels were very similar to pure diesel, making butyl butyrate an interesting diesel substitute. The emission analysis demonstrated lower soot and CO emissions, similar hydrocarbons levels and slightly increased NOx levels compared with using pure diesel. The high activity of lipase in diesel and the compatibility between diesel and butyl butyrate opens up the possibility to develop fuel blending systems where the synthesis of the blend-in component occurs directly in the fuel.
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| 10. |
- Wiinikka, Henrik, et al.
(författare)
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Fate of inorganic elements during fast pyrolysis of biomass in a cyclone reactor
- 2017
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 203, s. 537-547
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Tidskriftsartikel (refereegranskat)abstract
- In order to reduce ash related operational problem and particle emissions during pyrolysis oil combustion it is important to produce pyrolysis oil with very low concentration of inorganics. In this paper, the distribution of all major inorganic elements (S, Si, Al, Ca, Fe, K, Mg, Mn, Na, P, Ti and Zn) in the pyrolysis products (solid residue and two fractions of pyrolysis oil) was investigated during pyrolysis of stem wood, bark, forest residue, salix and reed canary grass. The raw materials were pyrolysed in a cyclone reactor and the produced pyrolysis oils were recovered as two oil fractions, a condensed fraction and an aerosol fraction. The inorganic composition of the ingoing raw material, the solid residue and the two pyrolysis oil fractions were analysed with inductively coupled plasma spectrometry techniques. All major inorganic elements, except sulphur, were concentrated in the solid residue. A significant amount of sulphur was released to the gas phase during pyrolysis. For zinc, potassium and iron about 1–10 wt% of the ingoing amount, depending on the raw material, was found in the pyrolysis oil. For the rest of the inorganics, generally less than 1 wt% of the ingoing amount was found in the pyrolysis oil. There were also differences in distribution of inorganics between the condensed and the aerosol oil fractions. The easily volatilized inorganic elements such as sulphur and potassium were found to a larger extent in the aerosol fraction, whereas the refractory elements were found to a larger extent in the condensed fraction. This implies that oil fractionation can be a method to produce oil fractions with different inorganic concentrations which thereafter can be used in different technical applications depending on their demand on the inorganic composition of the pyrolysis oil.
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