| 1. |
- Bergvall, Niklas, et al.
(författare)
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Continuous Slurry Hydrocracking of Biobased Fast Pyrolysis Oil
- 2021
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Ingår i: Energy & Fuels. - : American Chemical Society. - 0887-0624 .- 1520-5029. ; 35:3, s. 2303-2312
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Tidskriftsartikel (refereegranskat)abstract
- Co-refining of fast pyrolysis bio-oil together with fossil oil in existing refinery infrastructure is an attractive and cost-efficient route to conversion of lignocellulosic biomass to transportation fuel. However, due to large differences in properties between the two oils, special notice is needed to reduce process-related issues. Here, fast pyrolysis bio-oil produced from lignocellulosic biomass was co-refined with vacuum gas oil at a 20:80 weight ratio in continuous operation in a pilot-scale slurry hydrocracker in order to investigate the impact of process parameters on product quality and process performance. Mass balances together with product characterization were used to investigate product yields, product composition, and hydrodeoxygenation. Best conversion and hydrodeoxygenation of the fast pyrolysis bio-oil was achieved using an unsupported catalyst loading of 900 ppm Mo with either a low temperature (410 °C) and long residence time (2 h) or higher temperature (435 °C) and shorter residence time (1 h). These settings resulted in about 94% hydrodeoxygenation but also led to highest yield of biogenic carbon to gas phase (40-43 wt %) and lowest yield of biogenic carbon to oil fractions (53-56 wt %) as well as the water fraction (3-5 wt %). Successfully, coke yield remained low at around 0.07-0.10 wt % for all performed runs, which was comparable to the insoluble particle content in the feed due to the presence of particles in the untreated fast pyrolysis bio-oil. Co-processing pyrolysis oil with fossil oil in a slurry hydrocracker seems to be a robust process with regard to coke formation, which should lead to reduced plugging issues compared to fixed bed hydrotreaters. Although this study gives a brief understanding of the effect of process parameters on the processing of fast pyrolysis bio-oil, further research is required to find optimal process parameters and to fully comprehend the possibilities and limitations for production of transportation fuels from fast pyrolysis bio-oil using this technology.
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| 2. |
- Carlsson, Per, et al.
(författare)
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Slag Formation During Oxygen Blown Entrained-Flow Gasification of Stem Wood
- 2014
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 28:11, s. 6941-6952
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Tidskriftsartikel (refereegranskat)abstract
- Stem wood powders were fired in a mullite-lined pilot-scale oxygen-blown pressurized entrained-flow gasifier. During repeated campaigns involving increases in fuel load and process temperature, slag formations that eventuated in the blockage of the gasifier outlet were observed. These slags were retrieved for visual and chemical characterization. It was found that the slags had very high contents of Al and, in particular, high Al/Si ratios that suggest likely dissolution of the mullite-based refractory of the gasifier lining due to interactions with the fuel ash. Possible causes for the slag formation and behavior are proposed, and practical implications for the design of future stem wood entrained-flow gasifiers are also discussed
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| 3. |
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| 4. |
- Holmgren, Per, et al.
(författare)
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Size, shape, and density changes of biomass particles during rapid devolatilization
- 2017
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Ingår i: Fuel. - : Elsevier BV. - 0016-2361 .- 1873-7153. ; 206, s. 342-351
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Tidskriftsartikel (refereegranskat)abstract
- Particle properties such as size, shape and density play significant roles on particle flow and flame propagationin pulverized fuel combustion and gasification. A drop tube furnace allows for experiments athigh heating rates similar to those found in large-scale appliances, and was used in this study to carryout experiments on pulverized biomass devolatilization, i.e. detailing the first stage of fuel conversion.The objective of this study was to develop a particle conversion model based on optical informationon particle size and shape transformation. Pine stem wood and wheat straw were milled and sieved tothree narrow size ranges, rapidly heated in a drop tube setup, and solid residues were characterized usingoptical methods. Different shape descriptors were evaluated and a shape descriptor based on particleperimeter was found to give significant information for accurate estimation of particle volume. The opticalconversion model developed was proven useful and showed good agreement with conversion measuredusing a reference method based on chemical analysis of non-volatilized ash forming elements.The particle conversion model presented can be implemented as a non-intrusive method for in-situ monitoringof particle conversion, provided density data has been calibrated.
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| 5. |
- Jannasch, Anna-Karin, et al.
(författare)
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ANALYSIS OF P2G/P2L SYSTEMS IN PITEÅ/NORRBOTTEN FOR COMBINED PRODUCTION OF LIQUID AND GASEOUS BIOFUELS : Report from an f3 project
- 2016
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- This report is the result of a collaborative project within the Swedish Knowledge Centre for Renewable Transportation Fuels (f3). f3 is a networking organization, which focuses on development of environmentally, economically and socially sustainable renewable fuels, and Provides a broad, scientifically based and trustworthy source of knowledge for industry, governments and public authorities, Carries through system oriented research related to the entire renewable fuels value chain, Acts as national platform stimulating interaction nationally and internationally.f3 partners include Sweden’s most active universities and research institutes within the field, as well as a broad range of industry companies with high relevance. f3 has no political agenda and does not conduct lobbying activities for specific fuels or systems, nor for the f3 partners’ respective areas of interest.The f3 centre is financed jointly by the centre partners, the Swedish Energy Agency and the region of Västra Götaland. f3 also receives funding from Vinnova (Sweden’s innovation agency) as a Swedish advocacy platform towards Horizon 2020. Chalmers Industriteknik (CIT) functions as the host of the f3 organization (see www.f3centre.se).
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| 6. |
- Johansson, Ann-Christine, et al.
(författare)
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Comparison of co-refining of fast pyrolysis oil from Salix via catalytic cracking and hydroprocessing
- 2023
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Ingår i: Biomass and Bioenergy. - : Elsevier Ltd. - 0961-9534 .- 1873-2909. ; 172
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Tidskriftsartikel (refereegranskat)abstract
- Lignocellulosic biomass from energy crops, i.e., short rotation coppice willows such as Salix spp., can be used as feedstock for production of transportation biofuels. Biomass conversion via fast pyrolysis followed by co-refining with fossil oil in existing refinery infrastructure could enable a fast introduction of large-scale production of biofuels. In this study, Salix was first liquefied using ablative fast pyrolysis in a pilot scale unit. The resulting pyrolysis oil, rich in oxygenates, was thereafter co-refined in 20 wt% ratio with fossil feedstock using two separate technologies, a fluidized catalytic cracking (FCC) laboratory unit and a continuous slurry hydroprocessing pilot plant. In the FCC route, the pyrolysis oil was cracked at 798 K using a commercial FCC catalyst at atmospheric pressure, while in the hydroprocessing route, the oil was processed at 693 K and a hydrogen pressure of 15 MPa in the presence of an unsupported molybdenum sulfide catalyst. Both routes resulted in significant deoxygenation (97 wt% versus 93 wt%). It is feasible to co-refine pyrolysis oil using both methods, the main difference being that the hydroprocessing results in a significantly higher biogenic carbon yield from the pyrolysis oil to liquid and gaseous hydrocarbon products (92 wt%) but would in turn require input of H2. In the cracking route, besides the liquid product, a significant part of the biogenic carbon ends up as gas and as coke on the catalyst. The choice of route depends, among other factors, on the available amount of bio-oil and refining infrastructures. © 2023 The Authors
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| 7. |
- Johansson, Ann-Christine, et al.
(författare)
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Particle formation during suspension combustion of different biomass powders and their fast pyrolysis bio-oils and biochars
- 2021
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Ingår i: Fuel processing technology. - : Elsevier B.V.. - 0378-3820 .- 1873-7188. ; 218
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Tidskriftsartikel (refereegranskat)abstract
- The fly ash formation during suspension combustion of five different biomass powders (stem wood, bark, forest residue, willow, and reed canary grass) and the corresponding products from fast pyrolysis (bio-oil and biochar) of the powders was investigated. The fifteen fuels were burned in a drop tube furnace under normal (20 vol-% O2) and oxygen-enriched combustion conditions (40 vol-% and 60 vol-% O2). The trends in the data were used to discuss differences in combustion behavior and devise recommendations for the use of the fuels. There was a general difference in fly ash formation mechanism between the solid fuels (biomass and biochar) and the bio-oil fuels, which was attributed to parts of the ash-forming elements in bio-oil being dissolved in the oil. Oxygen-enrichment did not affect the release of inorganic elements to the gas phase for bio-oil combustion. Since the bio-oils generate lower fly ash during combustion, ~100 times compared to the original biomasses, they should be reserved for combustion technologies demanding fuels with very low ash content, whereas the biochar should be used in large scale combustion facilities with advanced gas cleaning technology operated by teams with experience of handling ash related operational problems. © 2021 The Author(s)
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| 8. |
- Molinder, Roger, et al.
(författare)
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Characteristics of Particles in Pyrolysis Oil
- 2016
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Ingår i: Energy & Fuels. - : American Chemical Society (ACS). - 0887-0624 .- 1520-5029. ; 30:11, s. 9456-9462
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Tidskriftsartikel (refereegranskat)abstract
- Particles filtered out of pyrolysis oil produced through fast pyrolysis of stem wood, willow, reed canary grass, bark, and forest residue were characterized using scanning electron microscopy and energy-dispersive spectroscopy with the aim of identifying particle categories and discussing transport mechanisms of particles and inorganics into the oil. Particles filtered out of both the condensed and the aerosol fractions of the oil displayed three types of morphology: (i) char-like structures (1-15 μm), (ii) spheres (100 nm to 1 μm), and (iii) irregularly shaped residue (50-500 nm). The char-like structures were identified as char. The spheres and irregularly shaped residue shared morphology and composition with tar balls and organic particles with inorganic inclusions. These particles could have formed either during the fast pyrolysis stage or through precipitation from the oil during storage. All particles consisted mainly of C and O but also small amounts of inorganics. The particles from the aerosol fraction of the oil had higher inorganics content than the particles from the condensed fraction. The results were discussed, and suggested transport mechanisms of inorganics into particles were presented.
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| 9. |
- 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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| 10. |
- Molinder, Roger, et al.
(författare)
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Extractives in the Scandinavian pulp and paperindustry : Current and possible future applications
- 2018
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- The forest industry is one of Sweden’s most important business sectors. Thanks to its biobased rawmaterials and products, the forest industry plays a key role in the development towards asustainable, circular economy. To meet market needs, and to drive the growth of the circulareconomy, the forest industry is continually developing its processes and products. It is seeking to useits raw material, the forest, as efficiently as possible and is constantly seeking to improve quality andincorporate new functions into materials and products.Pulp and paper makes up the largest part of the forest industry, followed by sawn wood productsand products made from paper and paperboard. 3.9 million tons of pulp and 10.1 million tons ofpaper were produced in Sweden in 2016.The pulp and paper industry uses stem wood as its raw material. Stem wood consists of cellulose,hemicellulose, lignin, and extractives. Cellulose and hemicellulose are separated in the pulpingprocess and the economically most important components in wood. Lignin and extractives areusually burned to provide the mill with heat and power, but the use/needs has changed over timedue to development of more energy efficient mills. Today lignin is extracted from the black liquor forexternal use, while extractives are fractionated and used for production of a wide range of productssuch as, biodiesel, adhesives, and chemical intermediates.The extractives make up between 3 and 5 weight-% of the wood and consists of a wide range ofcompounds. The majority of those compounds are fatty acids such as oleic- and linoleic acid androsin acids, such as abietic- and pimaric acid. The remaining compounds are commonly referred to as“neutrals” and are dominated by β-sitosterol. The extractives in Scots pine for example, consist of 70% fatty acids, 20 % rosin acids and 5 % neutrals.Today, the extractives are separated at the pulp and paper mills during the regeneration of cookingchemicals into a product called crude tall oil (CTO). 2.5 million metric tons of CTO is producedglobally with 80% of the production situated in North America and Scandinavia. 1.3 million tons isproduced in North America and 600 000 tons is produced in Scandinavia. 2.0 million metric tons iscurrently refined globally, while the rest is used internally by the mills for the production of heat andpower.CTO is currently refined into a range of products which can be divided up into (i) chemicalintermediates, (ii) biodiesel, and (iii) tall oil pitch. The chemical intermediates are mostly used for theproduction of adhesives, while the biodiesel is used as a transport fuel, and the tall oil pitch is usedfor production of heat and power.To meet market needs, and to drive the growth of the circular economy, extractives could potentiallybe used for the production of other products, either through new refinement routes of CTO or novelextraction and separation methods from the raw material. In order to identify opportunities for theproduction of other extractives based products, the extractives value chain must first be mapped.Second, refinement routes as well as extraction and separation methods suitable for isolation andprocessing of valuable compounds must be identified.
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