Life cycle assessment of agricultural biogas production systems

Agricultural activities are large contributors to anthropogenic greenhouse gas emissions. This paper discussed the effectiveness of reducing agricultural emissions by using liquid manure to produce biogas. When using this technique, greenhouse gas emissions from manure storage are avoided and renewable energy is generated as heat and electricity in combined heat and power plants. The purpose of this study was to evaluate the environmental impacts of biogas production systems based on the methods of life cycle assessment. The traditional use of agricultural manures was compared with conventional energy production. The Gabi 4.3 software was used to create a model to evaluate the biogas production systems according to their environmental impact. In addition to the global warming potential, other impact categories were also used to evaluate the effects of the systems in eutrophication and acidification. It was concluded that environmental benefits can be obtained in terms of greenhouse gas emissions compared to electricity production from biogas with the typical German marginal electricity mix.