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The present page presents the results of the EMPA 2007 study. The whole text below is taken from the study itself and not an analysis of the Biofuels Platform.
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The objective of this study is to evaluate the environmental impact of the entire production chain of fuels made from biomass used in Switzerland. Firstly the study supplies an analysis of the possible environmental impacts of biofuels suitable as a basis for political decisions. Secondly a life-cycle analysis (LCA) of the various biofuels is performed, which can be used as a basis for granting an exemption from the excise duty on hydrocarbon oil. In addition, the impacts of fuel use are compared with other uses for bioenergy such as the generation of electricity and heat. The study based on the Swiss database of environmental inventories ecoinvent gives a holistic comparison of the environmental impacts of biofuels; however neither the costs of biofuels nor the social consequences of their production are evaluated. The results refer to average values from the year 2004 in the respective production countries and are to be taken as a snapshot of factors relevant to the fuels’ use in Switzerland. Therefore, the study cannot provide any answers to questions concerning future impacts, for instance, on food prices.
In principle, each of the biofuels assessed (bioethanol, biomethanol, biodiesel and biogas) could be produced in an environmentally friendly way. It mainly depends on what raw materials and production technologies are used. Most of the environmental impacts can be attributed to the agricultural cultivation of the various raw materials (feedstocks). The environmental impact from fuel processing is usually much lower. The environmental impact from the transport from the production site to Swiss filling stations is even less, even when the biofuels are produced overseas.
The figure below presents the balance of greenhouse gases of various biofuels production pathways according to the EMPA 2007 study. The results are given in kg CO2 per pers.km.
Figure : Greenhouse gas balance of biofuels (IPCC 2001)
The present study shows that with most biofuels there is a trade-off between minimizing greenhouse gases (GHG emissions) and a positive ecological balance (see figure below). It is true that GHG emissions can be reduced by more than 30% with a number of biofuels. However, most of these supply pathways show greater impacts than fossil fuels for various other environmental indicators.
The global ecological balance was determined using the Swiss method of ecological scarcity (or UBP), which evaluates the difference between environmental impacts and legal limits. The results of the evaluation according to the UBP method indicate a relatively negative image of biofuels. In the case of tropical agriculture, it is primarily the slashing and burning of rainforests that releases the largest quantities of CO2, causes an increase in air pollution and has massive impacts on biodiversity. Under our latitudes, the main causes of the bad environmental performance include the lower crop yields, the intensive use of fertilizers and the mechanical tilling of the soil.
Figure : Global ecological balance of biofuels (Ecological Scarcity, UBP 2006)
As opposed to conventional fuels, the environmental impacts of biofuels can be greatly reduced by specific measures. By means of sensitivity analyses, the study shows how, for instance, a reduction in methane leakage can improve the LCA of biogas production or what effect a prohibition of slash and burn would have on the LCA of biodiesel from palm oil.
Overall, the results of the study show that any promoting of biofuels by a tax break, for instance, must be done so as to target the best production pathways. Not all biofuels can reduce environmental impacts as compared to fossil fuels. Currently, of all the production pathways investigated, it is especially the use of biogenic wastes and/or residues and lignocellulosic biomass (e.g. grass, wood) that brings a reduction in environmental impact as compared with fossil fuels.
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The potential of domestic bioenergy today is limited and is likely to remain as such in the future. Bioenergy will not solve our energy problems. However, if the available biomass is transformed into energy in an efficient and environmentally friendly manner, while at the same time consumption is reduced and energy efficiency increased, these alternative energy carriers can together, with other forms of renewable energy, play a role in our future energy supply that should not be neglected.
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