Renewable methane – A technology evaluation by multi-criteria decision making from a European perspective

Natural gas (NG), as one fossil fuel with multiple applications, plays a major role in Europe. However, to face global climate change and accelerate the transition to a sustainable society, fossil fuels, such as NG have to be replaced in the long term. The aim of this paper is to evaluate the technical and economic aspects of emerging technology concepts for the production of renewable methane from biomass. Biochemical and thermochemical concepts are considered within the scope of this paper. To evaluate the different conversion technologies an adapted AHP (analytic hierarchy process) was developed, based on two methods AHP and utility value analysis. In total, 99 alternatives (bio- and thermochemical conversion) were evaluated. From the multi-criteria analysis, no single technology pathway was given preference. However, the choice of substrate was found to be a critical factor in comparing the technology options. Within biochemical conversion, organic waste alternatives were favoured, for the thermochemical conversion, residual forest wood. The goal, a comprehensive comparison of two different conversion pathways on a multi-criteria scale, was achieved, and has thus provided added value for the bioeconomy and biorefinery in research and policy aspects. Further, the methodology is expandable and transferable to other criteria and technologies.