COMBINED PROCESS FOR UTILIZING CRUDE BIOGAS COMPRISING CARBON DIOXIDE AND A USEFUL GAS

摘要

A cyclic process for alternating utilization of crude biogas comprises two modes of utilization, namely a useful gas provision and a conversion to power, having the following process steps: – in a first mode of utilization of useful gas provision, = 1a) providing alkali metal carbonate, = 1b) removing carbon dioxide from the crude biogas by reaction of the carbon dioxide with the alkali metal carbonate to form alkali metal hydrogencarbonate according to the reaction equation useful gas + alkali metal₂CO₃ + H₂O + CO₂ useful gas + alkali metal HCO₃, and = 1c) removing the alkali metal hydrogencarbonate and providing the useful gas; and – in a second mode of utilization of conversion to power: = 2a) combusting the crude biogas in a thermal engine (6) to generate electrical energy and waste heat, = 2b) utilizing the waste heat to regenerate the alkali metal hydrogencarbonate to give alkali metal carbonate according to the reaction equation 2 alkali metal H₂CO₃ alkali metal₂CO₃ + H₂O + CO₂, and = 2c) reusing the alkali metal carbonate formed in process step 1a).