Environmental life cycle analysis of a modern commercial-scale fibreglass composite-based biogas scrubbing system

Abstract

There are progressive trends in biogas scrubbing technologies. These technologies are mainly aimed at supplying cleaner biomethane by removing CO2. With increasing progress in the field, their environmental assessment is also becoming important. This study is focused on the life cycle analysis (LCA) of a modern commercial-scale biogas scrubbing-filtration system, exclusively made of fibreglass reinforced composite material. This system can effectively scrub CO2, sulphides, siloxanes, the water content of the biogas and provide up to 85% pure biomethane. The environmental sustainability of the scrubbing system is deliberated in terms of LCA scores for four feedstock ratios of cow/buffalo manure (CBM) and potato waste (PW) depicted as CBM100:PW0, CBM75:PW25, CBM50:PW50 and CBM0:PW100. A functional unit of 100 m3 of biogas and six LCA categories (climate change, terrestrial acidification, freshwater ecotoxicity, water consumption, fossil depletion and human toxicity) were selected. The significant impacts are determined in the categories of climate change (kg of CO2 eq.) as −1.20, 1.11, 1.07, −1.16, and fossil depletion (kg of oil eq.) as −9.50, 8.27, 8.01 and −9.91 for the four respective feedstock variants, CBM100:PW0, CBM75:PW25, CBM50:PW50 and CBM0:PW100. The feedstock CBM100:PW0 posed the least climate change impact and for the fossil depletion category, CBM0:PW100 is the least burdensome.