| 1. |
- Albertsson, Johannes, et al.
(författare)
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Effects of competition between short-rotation willow and weeds on performance of different clones and associated weed flora during the first harvest cycle
- 2014
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 70, s. 364-372
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Tidskriftsartikel (refereegranskat)abstract
- In order to assess the ability of willow clones to compete with weeds, willow shoot biomass and plant mortality were measured over the first harvest cycle for 10 commercial and two breeding clones at three different sites in southern Sweden. Two levels of weed pressure (weeded and not weeded) were employed and the effects of cutback or not after the first growing season were compared for willow clones under weed pressure. There were significant differences between clones in their ability to compete with weeds, measured as willow shoot growth reduction in plots with weeds, at two of the three sites. However, shoot biomass reduction due to weeds was large in all the clones, with Stina and SW Inger among the least affected. Mean shoot growth reduction after the first harvest cycle for the commercial clones was 68.3%, 91.2% and 94.3% at the three sites and the corresponding plant mortality was 9.8%, 57.3% and 56.2% under weed pressure. Significant clonal differences in yield, under weed-free conditions, were found at all three sites. Significant clonesite interactions were found for both growth reduction and biomass production. Cutting back shoots after the establishment season, under weed pressure, resulted in higher mean plant mortality and lower mean willow shoot biomass after one harvest cycle at two of the three sites. The weed flora was initially dominated by annuals, but became dominated by perennial weeds during the first harvest cycle. (C) 2014 Elsevier Ltd. All rights reserved.
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| 2. |
- Andersson, Jim, et al.
(författare)
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Methanol production via pressurized entrained flow biomass gasification : Techno-economic comparison of integrated vs. stand-alone production
- 2014
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 64, s. 256-268
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Tidskriftsartikel (refereegranskat)abstract
- The main objective with this work was to investigate techno-economically the opportunity for integrated gasification-based biomass-to-methanol production in an existing chemical pulp and paper mill. Three different system configurations using the pressurized entrained flow biomass gasification (PEBG) technology were studied, one stand-alone plant, one where the bark boiler in the mill was replaced by a PEBG unit and one with a co-integration of a black liquor gasifier operated in parallel with a PEBG unit. The cases were analysed in terms of overall energy efficiency (calculated as electricity-equivalents) and process economics. The economics was assessed under the current as well as possible future energy market conditions. An economic policy support was found to be necessary to make the methanol production competitive under all market scenarios. In a future energy market, integrating a PEBG unit to replace the bark boiler was the most beneficial case from an economic point of view. In this case the methanol production cost was reduced in the range of 11-18 Euro per MWh compared to the stand-alone case. The overall plant efficiency increased approximately 7%-units compared to the original operation of the mill and the non-integrated stand-alone case. In the case with co-integration of the two parallel gasifiers, an equal increase of the system efficiency was achieved, but the economic benefit was not as apparent. Under similar conditions as the current market and when methanol was sold to replace fossil gasoline, co-integration of the two parallel gasifiers was the best alternative based on received IRR.
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| 3. |
- Andersson, Viktor, 1983, et al.
(författare)
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Algae-based biofuel production as part of an industrial cluster
- 2014
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 71, s. 113-124
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Tidskriftsartikel (refereegranskat)abstract
- This paper presents a study on the production of biofuels from algae cultivated in municipal wastewater in Gothenburg, Sweden. A possible biorefinery concept is studied based on two cases; Case A) combined biodiesel and biogas production, and Case B) only biogas production. The cases are compared in terms of product outputs and impact on global CO2 emissions mitigation. The area efficiency of the algae-based biofuels is also compared with other biofuel production routes. The study investigates the collaboration between an algae cultivation, biofuel production processes, a wastewater treatment plant and an industrial cluster for the purpose of utilizing material flows and industrial excess heat between the actors. This collaboration provides the opportunity to reduce the CO2 emissions from the process compared to a stand-alone operation. The results show that Case A is advantageous to Case B with respect to all studied factors. It is found that the algae-based biofuel production routes investigated in this study has higher area efficiency than other biofuel production routes. The amount of algae-based biofuel possible to produce corresponds to 31 MWfuel for Case A and 26 MWfuel in Case B.
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| 4. |
- Anugwom, Ikenna, et al.
(författare)
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Towards optimal selective fractionation for Nordic woody biomass using novel amine–organic superbase derived switchable ionic liquids (SILs)
- 2014
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Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 70, s. 373-381
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Improved fractionation process conditions for wood dissolution with switchable ionic liquids (SILs) were determined. The short time, high temperature (STHT) system was introduced as a selective and efficient way to extract components from lignocellulosic material. A SIL based on monoethanol amine (MEA) and 1,8-diazabicyclo-[5.4.0]-undec-7-ene (DBU) formed via coupling with SO2, was applied as a solvent in a 1:3 weight ratio with water. In essence, selective dissolution of mainly lignin was achieved by means of the aqueous SIL at 160 °C (∼6.1 bar corresponding to the vapor pressure of water) in 2 h and in a pressure vessel, for both hard- and soft-wood. About 95 wt-% of wood lignin was extracted. The dissolved components in the spent SIL were recovered by the addition of an anti-solvent whereupon over 70% of the dissolved components were recovered; the recovered fraction contained 19 wt-% hemicellulose while the rest of the material was in essence lignin. The non-dissolved, fluffy material contained ∼70 wt-% cellulose and ∼20 wt-% hemicellulose – a consistency resembling that of Kraft pulp.
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| 5. |
- Backlund, Ingegerd, et al.
(författare)
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Biorefinery product potentials using tree biomass as feedstock - A survey on opportunities and threats to the new wood products industry
- 2014
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 70, s. 207-216
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Tidskriftsartikel (refereegranskat)abstract
- A questionnaire survey on the potential of biorefinery products was carried out along with an analysis of energy prices and wood assortments. Electricity production was considered to have the potential for the highest investment return over ten years, followed by solid wood products, bioenergy assortments and textiles. Only pulp and paper were perceived as returning lower potential investment values over the next ten years than over the next five. Of the survey respondents, 95% believed that the value of woody biomass will increase over the next ten years, mainly through its replacement of oil-based products, although there will be problems due to lack of suitable raw material. A wide range of chemical products were described but a greater confidence in more traditional solid fuel products still prevails. Stemwood is the most favored part of the tree with only a few respondents saying that they wanted specific chemicals extracted. The electricity price and wood fuel price were found to be strongly correlated and 91% of respondents said their products would be affected by the electricity price. Electricity prices within OECD countries are expected to increase by 15% from 2011 to 2035, with wood fuel prices increasing by roughly 10% during the same period. Therefore, the electricity price could become a decisive factor in the future use of biomass in biorefineries. Our results suggest that large-scale commercial biorefinery production will soon be possible but new wood assortment classifications are needed that include both fiber properties and chemical properties such as extractive content.
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| 6. |
- Basile, Francesco, et al.
(författare)
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Steam reforming of hot gas from gasified wood types and miscanthus biomass
- 2011
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Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 35:Supplement 1, s. S116-S122
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Tidskriftsartikel (refereegranskat)abstract
- The reforming of hot gas generated from biomass gasification and high temperature gas filtration was studied in order to reach the goal of the CHRISGAS project: a 60% of synthesis gas (as x(H2)+ x(CO) on a N2 and dry basis) in the exit gas, which can be converted either into H2 or fuels. A Ni-MgAl2O4 commercial-like catalyst was tested downstream the gasification of clean wood made of saw dust, waste wood and miscanthus as herbaceous biomass. The effect of the temperature and contact time on the hydrocarbon conversion as well as the characterization of the used catalysts was studied. Low (<600 °C), medium (750°C–900 °C) and high temperature (900°C–1050 °C) tests were carried out in order to study, respectively, the tar cracking, the lowest operating reformer temperature for clean biomass, the methane conversion achievable as function of the temperature and the catalyst deactivation. The results demonstrate the possibility to produce an enriched syngas by the upgrading of the gasification stream of woody biomass with low sulphur content. However, for miscanthusthe development of catalysts with an enhanced resistance to sulphur poison will be the key point in the process development.
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| 7. |
- Bengtsson, Sune, 1946-
(författare)
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The CHRISGAS Project
- 2011
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Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 35:S1, s. S2-S7
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Tidskriftsartikel (refereegranskat)
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| 8. |
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| 9. |
- Berghel, Jonas, et al.
(författare)
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Superheated steam drying of sawdust in continuous feed spouted beds : a design perspective
- 2014
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 71:0, s. 228-234
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Tidskriftsartikel (refereegranskat)abstract
- Spouted bed drying technology shows promising results for the drying of unscreened sawdust in superheated steam. In this paper, the experiences from designing, running and evaluating two spouted bed continuous feed dryers are presented. Stable running conditions and drying results have been achieved. This has been particularly important for sawdust that will be compressed into pellets or briquettes. The spouted bed superheated steam dryer also shows high potential for energy efficient integration into sawmills. Our recommendation is thus, to use the outlet steam temperature as the control parameter for the outlet moisture content. A drying rate above and one below the fibre saturation level, can be identified. Visual observations through the viewing glass in the drying zone in both the dryers clearly showed that not all of the material participated in the spout at all times; there were, however, no indications of dead zones. A heat transfer analysis indicated that only about 70% of the surface area of the material was in thermal contact with the steam. This paper sums up the experiences regarding drying properties, control and system properties obtained when sawdust is dried using superheated steam as the drying medium. Further work on standardised dryers in series or in parallel is necessary to increase the capacity in the spouted bed dryer.
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| 10. |
- Berndes, Göran, 1966, et al.
(författare)
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Strategies For 2nd Generation Biofuels In Eu - Co-firing to stimulate feedstock supply development and process integration to improve energy efficiency and economic competitiveness
- 2010
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 34:2, s. 227-236
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Tidskriftsartikel (refereegranskat)abstract
- The present biofuel policies in the European Union primarily stimulate 1st generation biofuels that are produced based on conventional food crops. They may be a distraction fromlignocellulose based 2nd generation biofuels – and also from biomass use for heat and electricity – by keeping farmers’ attention and significant investments focusing on firstgeneration biofuels and the cultivation of conventional food crops as feedstocks. This article presents two strategies that can contribute to the development of 2nd generation biofuels based on lignocellulosic feedstocks. The integration of gasification-based biofuel plants in district heating systems is one option for increasing the energy efficiency and improving the economic competitiveness of such biofuels. Another option, biomass co-firing with coal,generates high-efficiency biomass electricity and reduces CO2 emissions by replacing coal. It also offers a near-term market for lignocellulosic biomass, which can stimulate development of supply systems for biomass also suitable as feedstock for 2nd generation biofuels. Regardless of the long-term priorities of biomass use for energy, the stimulation of lignocellulosic biomass production by development of near term and cost-effective markets isjudged to be a no-regrets strategy for Europe. Strategies that induce a relevant development and exploit existing energy infrastructures in order to reduce risk and reach lower costs, are proposed an attractive complement the present and prospective biofuel policies.
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