Biogas

Biogas is the methane-rich gas from anaerobic digestion of organic feedstock: wastewater, manure, crop residues, food waste, and palm-oil mill effluent. Two reactor forms are written up separately: the in-ground covered digester and the stirred tank.

What happens next is a choice of product. Burn the gas in a genset and export the electricity, which is still a standard route to the grid. Remove hydrogen sulfide and upgrade it to biomethane. Liquefy that to bio-LNG. Or use the biogenic carbon dioxide with hydrogen in biological methanation. The digestate can go toward biofertiliser.

Covers, lightning, and insurance are an operating problem, not a footnote. See inflated biogas covers.