An assessment of electrified methanol production from an environmental perspective

Abstract

The sustainability of novel electrified processes for methanol production, including plasma-assisted and electrically heated thermocatalytic dry methane reforming based processes, is assessed. Conceptual process design is applied to obtain the life cycle inventory data to perform the ex-ante life cycle assessment, with a focus on the climate change impacts expressed in kg CO₂-eq. per kg_MeOH. The plasma-assisted technology results in lower greenhouse gas emissions than the conventional thermocatalytic counterpart, when the plasma reactor itself is powered by renewable (solar or wind) electricity. This also holds for most of the environmental indicators; only a few trade-offs on (eco)toxicity, particulate matter and mineral resource indicators were found, due to the impact from wind turbine construction. For a fully electrified modus operandi, i.e. when all unit operations are electrified by renewable sources, both the plasma-assisted and thermocatalytic technologies result in low climate change impacts, in the range of 0.6–0.7 kg CO₂-eq. per kg_MeOH. This is comparable to the climate change impact of CO₂-based methanol production utilizing electrolytic H₂. Finally, it is estimated that up to 43% CO₂ abatement may be possible by replacing the state-of-the-art (natural gas steam reforming-based) methanol production process with electrified alternatives running on renewable electricity.