| 1. |
- Boman, Christoffer, 1970-, et al.
(författare)
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Effects of increased small-scale biomass pellet combustion on ambient air quality in residential areas : A parametric dispersion modeling study
- 2003
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Ingår i: Biomass and Bioenergy. - : Elsevier. - 0961-9534 .- 1873-2909. ; 24:6, s. 465-474
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Tidskriftsartikel (refereegranskat)abstract
- Sweden's goals of contemporaneously reducing CO2 emissions and phasing out nuclear power will require a maximum utilization of biomass fuels. This would imply a significant shift from electricity and fuel oil to biomass generated heat, but must also be accomplished without a deterioration of the local air quality. The most suitable energy carrier seems to be pelletized biomass fuels with their associated low emissions and considerable residential conversion potential. Using an underlying statistical design, a parametric dispersion modeling study was performed to estimate and illustrate the combined effects of source-specific, meteorological and modeling variables on the ambient air quality in a typical residential area for different conversion scenarios. The work nicely illustrated the benefits of combining statistical designs with model calculations. It further showed that the concentration of combustion related ambient THC was strongly related to conditions affecting the source strength, but only weakly to the dispersion conditions and model variables. Time of year (summer or winter); specific emission performance; extent of conversion from electricity; conversion from wood log combustion; and specific efficiency of the pellet appliances showed significant effects in descending order. The effects of local settings and model variables were relatively small, making the results more generally applicable. To accomplish the desired conversion to renewable energy in an ecologically and sustainable way, the emissions would have to be reduced to a maximum advisable limit of (given as CH4). Further, the results showed the potential positive influence by conversion from wood log to low emission pellet combustion.
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| 2. |
- Ostwald, Madelene, 1966, et al.
(författare)
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Mapping energy crop cultivation and identifying motivational factors among Swedish farmers
- 2013
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 50, s. 25-34
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Tidskriftsartikel (refereegranskat)abstract
- Based on a meta-study, the paper describes the existing options, areal extents, and Swedish farmers' conditions for energy crop production promoted by the governments to mitigate and adapt to climate change. The drivers of and barriers to cultivating various energy crops are described in terms of a variety of motivational factors. The approach used peer-reviewed and gray literature using three Internet sources. Questions addressed include the energy crops available to Swedish farmers and how well established they are in terms of areal extent. What drivers of and barriers to growing energy crops do farmers perceive? How do various motivational factors for these drivers and barriers correspond to the adoption of certain energy crops? The results indicate that 13 energy-related crops are available, of which straw (a residue), oil crops, and wheat are the most extensively produced in terms of cultivated area. Results confirm earlier research findings that converting from annual to perennial crops and from traditional crops or production systems to new ones are important barriers. Economic motivations for changing production systems are strong, but factors such as values (e.g., esthetic), knowledge (e.g., habits and knowledge of production methods), and legal conditions (e.g., cultivation licenses) are crucial for the change to energy crops. Finally, there are knowledge gaps in the literature as to why farmers decide to keep or change a production system. Since the Swedish government and the EU intend to encourage farmers to expand their energy crop production, this knowledge of such motivational factors should be enhanced.
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| 3. |
- Berndes, Göran, 1966, et al.
(författare)
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The contribution of biomass in the future global energy supply: A review of 17 studies
- 2003
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Ingår i: Biomass and Bioenergy. - 1873-2909 .- 0961-9534. ; 25:1, s. 1-28
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Tidskriftsartikel (refereegranskat)abstract
- This paper discusses the contribution of biomass in the future global energy supply. The discussion is based on a review of 17 earlier studies on the subject. These studies have arrived at widely different conclusions about the possible contribution of biomass in the future global energy supply (e.g., from below 100 EJ yr-1 to above 400 EJ yr-1 in 2050). The major reason for the differences is that the two most crucial parameters - land availability and yield levels in energy crop production - are very uncertain, and subject to widely different opinions (e.g., the assessed 2050 plantation supply ranges from below 50 EJ yr-1 to almost 240 EJ yr-1). However, also the expectations about future availability of forest wood and of residues from agriculture and forestry vary substantially among the studies. The question how an expanding bioenergy sector would interact with other land uses, such as food production, biodiversity, soil and nature conservation, and carbon sequestration has been insufficiently analyzed in the studies. It is therefore difficult to establish to what extent bioenergy is an attractive option for climate change mitigation in the energy sector. A refined modeling of interactions between different uses and bioenergy, food and materials production - i.e., of competition for resources, and of synergies between different uses - would facilitate an improved understanding of the prospects for large-scale bioenergy and of future land-use and biomass management in general. © 2003 Elsevier Science Ltd. All rights reserved.
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| 4. |
- Berndes, Göran, 1966, et al.
(författare)
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The feasibility of large-scale lignocellulose-based bioenergy production
- 2001
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Ingår i: Biomass and Bioenergy. - 1873-2909 .- 0961-9534. ; 20:5, s. 371-383
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Tidskriftsartikel (refereegranskat)abstract
- Global, large-scale use of bioenergy may replace a significant part of present fossil fuel use. We show that labor availability and water resources are large compared to those required to operate a bioenergy system of such size. The present study contradicts the assertion by Giampietro et al. [Bioscience 47(9) (1997) 587], that labor and water availability provide invincible barriers to a large-scale use of biofuels. We examine water and labor requirements under more reasonable assumptions about bioenergy supply options and demand levels. Bioenergy supplies are based on dedicated plantations of lignocellulosic crops and bioenergy demand is based on the renewable intensive global energy scenarios (RIGES). We find that labor and water requirements are an order of magnitude lower than the estimates by Giampietro et al. For instance, labor requirements do not exceed 1 percent of the estimated total work force in any country. © 2001 Elsevier Science Ltd.
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| 5. |
- Blennow, Kristina, et al.
(författare)
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Forest owner motivations and attitudes towards supplying biomass for energy in Europe
- 2014
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 67, s. 223-230
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Tidskriftsartikel (refereegranskat)abstract
- The European Commission expects the use of biomass for energy in the EU to increasesignificantly between 2010 and 2020 to meet a legally binding target to cover at least 20%of EU’s total energy use from renewable sources in 2020. According to estimates made bythe member states of the EU, the direct supply of biomass from forests is expected toincrease by 45% on a volume basis between 2006 and 2020 in response to increasingdemand (Beurskens LWM, Hekkenberg M, Vethman P. Renewable energy projections aspublished in the national renewable energy action plans of the European Member states.ECN and EEA; 2011. http://https://www.ecn.nl/docs/library/report/2010/e10069.pdf[accessed 25.04.2014]; Dees M, Yousef A, Ermert J. Analysis of the quantitative tables ofthe national renewable energy action plans prepared by the 27 European Union MemberStates in 2010. BEE working paper D7.2. Biomass Energy Europe project. FELIS e Departmentof Remote Sensing and landscape information Systems, University of Freiburg,Germany; 2011). Our aims were to test the hypotheses that European private forestowners’ attitudes towards supplying woody biomass for energy (1) can be explained bytheir responses to changes in prices and markets and (2) are positive so that the forestbiomass share of the EU 2020 renewable energy target can be met. Based on survey datacollected in 2010 from 800 private forest owners in Sweden, Germany and Portugal ourresults show that the respondents’ attitudes towards supplying woody biomass for energycannot be explained as direct responses to changes in prices and markets. Our results,furthermore, imply that European private forest owners cannot be expected tosupply the requested amounts of woody biomass for energy to meet the forest biomassshare of the EU 2020 renewable energy target, at least if stemwood is to play theimportant role as studies by Verkerk PJ, Anttila P, Eggers J, Lindner M, Asikainen A. Therealisable potential supply of woody biomass fromforests in the European Union. For EcolManag 2011;261: 2007e2015, UNECE and FAO. The European forest sector outlook study II 2010e2030. United Nations, New York and Geneva; 2011 [abbreviated to EFSOS II] andElbersen B, Staritsky I, Hengeveld G, Schelhaas MJ, Naeff H, Bo¨ ttcher H. Atlas of EUbiomass potentials; 2012. Available from: http://www.biomassfutures.eu [accessed14.10.2013] suggest.
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| 6. |
- 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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| 7. |
- Endalew, Abebe K., et al.
(författare)
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Inorganic heterogeneous catalysts for biodiesel production from vegetable oils
- 2011
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 35:9, s. 3787-3809
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Forskningsöversikt (refereegranskat)abstract
- Biofuels are renewable solutions to replace the ever dwindling energy reserves and environmentally pollutant fossil liquid fuels when they are produced from low cost sustainable feedstocks. Biodiesel is mainly produced from vegetable oils or animal fats by the method of transesterification reaction using catalysts. Homogeneous catalysts are conventionally used for biodiesel production. Unfortunately, homogeneous catalysts are associated with problems which might increase the cost of production due to separation steps and emission of waste water. Inorganic heterogeneous catalysts are potentially low cost and can solve many of the problems encountered in homogeneous catalysts. Many solid acid and base inorganic catalysts have been studied for the transesterification of various vegetables oils. The work of many researchers on the development of active, tolerant to water and free fatty acids (FFA), as well as stable inorganic catalysts for biodiesel production from vegetable oils are reviewed and discussed.
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| 8. |
- Olsson, Maria, 1976, et al.
(författare)
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Emissions from burning of softwood pellets
- 2004
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 27:6, s. 607-611
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Tidskriftsartikel (refereegranskat)abstract
- Softwood pellets from three different Swedish manufacturers were burnt in laboratory scale to determine compounds emitted. The emissions were sampled on Tenax cartridges and assessed by gas chromatography and mass spectrometry. No large differences in the emissions from pellets from different manufacturers were observed. The major primary semi-volatile compounds released during flaming burning were 2-methoxyphenols from lignin. The methoxyphenols are of interest due to their antioxidant effect, which may counteract health hazards of aromatic hydrocarbons. Glowing combustion released the carcinogenic benzene as the predominant aromatic compound. However, the benzene emissions were lower than from flaming burning. To relate the results from the laboratory burnings to emissions from pellet burners and pellet stoves, chimney emissions were determined for different burning equipments. The pellet burner emitted benzene as the major aromatic compound, whereas the stove and boiler emitted phenolic antioxidants together with benzene. As the demand for pellets increases, different biomass wastes will be considered as raw materials. Ecological aspects and pollution hazards indicate that wood pellets should be used primarily for residential heating, whereas controlled large-scale combustion should be preferred for pellets made of most other types of biomass waste.
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| 9. |
- Sparrevik, Magnus, et al.
(författare)
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Emissions of gases and particles from charcoal/biochar production in rural areas using medium-sized traditional and improved retort kilns
- 2015
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Ingår i: Biomass and Bioenergy. - : Elsevier BV. - 0961-9534 .- 1873-2909. ; 72, s. 65-73
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Tidskriftsartikel (refereegranskat)abstract
- Charcoal is used for cooking in many parts of the developing world. Charcoal from agricultural materials can also be used as a soil amendment to enhance agricultural production, and is often termed biochar in this case. Charcoal may be produced in various types and scales of systems, but for rural tropical areas, traditional kiln technologies without treatment of the pyrolysis gases dominate. Traditional charcoal industry is considered to be both inefficient and polluting, emitting harmful off-gases containing methane, carbon monoxide and particles. Retort kilns, which recirculate and combust the pyrolysis gases internally have been claimed to overcome this problem. Even though retort technology has frequently been discussed, this paper is the first study determining gas emission factors for operational retort kilns in rural tropical areas. The mean emission factors for the retort ldlns found in this study using identical feedstock were (in g kg(-1) charcoal); carbon dioxide (CO2) = 1950 +/- 209, carbon monoxide (CO) = 157 +/- 64, nonmethane volatile organic components (NMVOC) = 6.1 +/- 3.4, methane (CH4) = 24 +/- 17, total solid particles (TSP) = 12 +/- 18, products of incomplete combustion (plc) = 200 +/- 97 and nitric oxides (NOx) = 1.8 +/- 1.0. The corresponding value for the non-retort ldlns tested was in general higher; CO2 = 2380 +/- 973, CO = 480 +/- 141, NMVOC = 13 +/- 3.8, CH4 = 54 +/- 29, TSP = 7.9 +/- 2.6, PIC = 554 +/- 138 and NOx = 4.3 +/- 1.6. The difference between the kiln types was statistically significant (p < 0.05) for CO, NMVOC, PIC and NOx. However, the retort kilns consumed ignitable fuel such as wood in the start-up phase to reach pyrolysis temperature resulting in insignificant difference in yield between retort and non-retort kilns. In addition, retort kilns are more costly than traditional kilns, which may be challenging for implementation. It is therefore important to continue design development, especially with regard to wood consumption during the start-up phase.
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| 10. |
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