| 1. |
- Berglund, Maria, et al.
(author)
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Assessment of energy performance in the life-cycle of biogas production
- 2006
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In: Biomass & Bioenergy. - : Elsevier BV. - 1873-2909 .- 0961-9534. ; 30:3, s. 254-266
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Journal article (peer-reviewed)abstract
- Energy balances are analysed from a life-cycle perspective for biogas systems based on 8 different raw materials. The analysis is based on published data and relates to Swedish conditions. The results show that the energy input into biogas systems (i.e. large-scale biogas plants) overall corresponds to 20-40% (on average approximately 30%) of the energy content in the biogas produced. The net energy output turns negative when transport distances exceed approximately 200 kin (manure), or up to 700 km (slaughterhouse waste). Large variations exist in energy efficiency among the biogas systems studied. These variations depend both on the properties of the raw materials studied and on the system design and allocation methods chosen. The net energy output from biogas systems based on raw materials that have high water content and low biogas yield (e.g. manure) is relatively low. When energy-demanding handling of the raw materials is required, the energy input increases significantly. For instance, in a ley crop-based biogas system, the ley cropping alone corresponds to approximately 40% of the energy input. Overall, operation of the biogas plant is the most energy-demanding process, corresponding to 40-80% of the energy input into the systems. Thus, the results are substantially affected by the assumptions made about the allocation of a plant's entire energy demand among raw materials, e.g. regarding biogas yield or need of additional water for dilution. (c) 2005 Elsevier Ltd. All rights reserved.
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| 5. |
- Berndes, Göran, 1966, et al.
(author)
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Multifunctional biomass production systems - an overview with presentation of specific applications in India and Sweden
- 2008
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In: Biofuels, Bioproducts and Biorefining. - : Wiley. - 1932-104X .- 1932-1031. ; 2:1, s. 16-25
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Journal article (peer-reviewed)abstract
- This perspective discusses multi-functional biomass production systems, which are located, designed, integrated and managed so as to provide specific environmental services, in addition to biomass supply. Besides discussing the general concept and outlining a range of different possible applications, we present in somewhat more detail specific applications of such systems for the cases of Sweden and India. The overall conclusion is that the environmental benefits from a large-scale establishment of multi-functional biomass production systems could be substantial. Given that suitable mechanisms to put a premium on the provided environmental services can be identified and implemented, additional revenues can be linked to biomass production systems and this could enhance the socioeconomic attractiveness and significantly improve the competitiveness of the produced biomass on the market. The provision of additional environmental services also contributes to local sustainable development, which is in many cases a prerequisite for local support for the production systems.
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| 8. |
- Börjesson, Pål, et al.
(author)
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Biogas as a resource-efficient vehicle fuel
- 2008
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In: Trends in Biotechnology. - : Elsevier BV. - 0167-7799. ; 26:1, s. 7-13
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Journal article (peer-reviewed)abstract
- There are currently strong incentives for increased use of renewable fuels in the transport sector worldwide. However, some bioethanol and biodiesel production routes have limitations with regard to resource efficiency and reduction of greenhouse gases. More efficient biofuel systems are those based on lignocelluloses and novel conversion technologies. A complementary strategy to these is to increase the production of biogas from the digestion of organic residues and energy crops, or from byproducts of ethanol and biodiesel production. Compared with other biomass-based vehicle fuels available so far, biogas often has several advantages from an environmental and resource-efficiency perspective. This provides the motivation for further technological development aiming to reduce costs and thereby increased economic competitiveness of biogas as a vehicle fuel.
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| 9. |
- Börjesson, Pål
(author)
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Biogas from waste materials as transportation fuel-benefits from an environmental point of view.
- 2008
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In: Water Science and Technology. - : IWA Publishing. - 0273-1223 .- 1996-9732. ; 57:2, s. 271-275
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Journal article (peer-reviewed)abstract
- In this paper various biogas systems based on waste materials have been analysed from an environmental point of view. The analyses are based on Swedish conditions using a systems analysis approach from an energy and life cycle perspective. The biogas produced is used as a transportation fuel replacing petrol in light-duty vehicles. The overall aims are to quantify the potential environmental effects when current waste handling and transportation fuel systems are replaced. A general conclusion is that the indirect environmental benefits (e.g. reduced emissions of ammonia and methane, and nitrogen leaching) from altered handling of organic waste materials and land-use may often significantly exceed the direct environmental benefits achieved when biogas replaces petrol (e.g. reduced emissions of carbon dioxide and air pollutants). Such indirect benefits are seldom considered when biogas is evaluated from an environmental point of view. However, the environmental impact from different biogas systems can vary significantly due to factors such as the waste materials utilised, different reference systems being replaced, and local conditions.
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