Faced by the concerning climate change worldwide and
agriculture-dependent
biochemical and energy-intensive thermochemical technologies, research
and development efforts in exploring sustainable ethanol synthesis
toward carbon neutrality are urgent. Recently, an electrochemical
process via the electrocatalytic CO2 reduction reaction
(CO2RR) to synthesize ethanol has emerged as a promising
alternative approach by directly consuming CO2 from the
atmosphere. Despite the fact that numerous remarkable electrocatalysts
with fascinating activity, selectivity, and stability have been extensively
uncovered in this field, environmental impacts of this technology
have rarely been acknowledged. Herein, a life cycle assessment (LCA)
study is conducted to evaluate the potential environmental impacts
and benefits of an innovative electrochemical process versus conventional
biochemical and thermochemical processes toward the sustainable synthesis
of 1 kg of ethanol. Impact assessment results revealed that with the
contemporary electricity mix, the electrochemical process is still
surpassed by the biochemical process, and its environmental benignity
is not pronounced, attributed to tremendous electricity utilities
accounting for 67.7–100% of impacts. However, it prevails over
the two conventional routes when powered by renewable energies, particularly
solar energy, with impact reduction ranging from 108.6 to 750.5%,
while providing the greatest benefits with respect to terrestrial
ecotoxicity (TETP). Carbon footprint further indicates that the electrochemical
process becomes competitive and reaches carbon neutrality once driven
by electricity with carbon intensity (CI) below 0.25 and 0.12 kg CO2 eq/kWh. Overall, in spite of its massive electricity utilities,
the electrochemical ethanol synthesis route is highly promising in
environmental impact remediation when coupled with renewable energies,
which calls for more efforts from researchers and governments to achieve
carbon neutrality and sustainability in years to come.