Comparative life cycle assessment of biogas plant configurations for a demand oriented biogas supply for flexible power generation

• Life cycle assessment of biogas plant configurations for flexible power generation.
• Environmental effects of biogas plants producing biogas on demand.
• Comparison of biogas storage and flexible biogas production concepts.
• Processing PF from bio waste increases GHG savings and agricultural biodiversity.
• Methane emissions can be reduced by thicker biogas storage membranes.

The environmental performance of biogas plant configurations for a demand – oriented biogas supply for flexible power generation is comparatively assessed in this study. Those configurations indicate an increased energy demand to operate the operational enhancements compared to conventional biogas plants supplying biogas for baseload power generation. However, findings show that in contrast to an alternative supply of power generators with natural gas, biogas supplied on demand by adapted biogas plant configurations saves greenhouse gas emissions by 54–65 g CO2-eq MJ−1 and primary energy by about 1.17 MJ MJ−1. In this regard, configurations with flexible biogas production profit from reduced biogas storage requirements and achieve higher savings compared to configurations with continuous biogas production. Using thicker biogas storage sheeting material reduces the methane permeability of up to 6 m3 d−1 which equals a reduction of 8% of the configuration’s total methane emissions.