From Carbon dioxide to Valuable Products

The focus of this report was to convert CO2 into a valuable product from a biogas stream, which was created by anaerobic digestion from cow manure. The related biogas stream was upgraded by removing H2S via activated carbon and CO2 was extracted via pressure swing absorption. The extracted CO2 could then be synthesized into various valuable products such as methane, methanol, formic acid or ethylene glycol. As all processes require relative high amounts of hydrogen, the obtained methane is combusted for electricity, designated for electrolysis, whereas the excess heat has not been utilized yet but could facilitate district heating for residential housing or other industrial applications. Out of the valuable products, methanol and formic acid are most promising candidates as they are feasible and economically attractive, where formic acid is most interesting due to its high market value and future prospects within fuel cells.