Decarbonizing Complex Chemical Processes via Heat Electrification: A Case Study on Acetic Acid Hydrogenation to Ethanol

Abstract Low-temperature process heat (<400 °C) electrification is a promising decarbonization pathway, yet its effectiveness depends on process design, grid carbon intensity (CI), and electricity costs. Here, we evaluate electrification of ethanol production via acetic acid hydrogenation—involving complex azeotropic separations and reaction–separation coupling—across three process layouts, with similar ethanol carbon recoveries (≥95%). We compare a fossil fuel baseline process against (a) simple electrification, where electric resistance heating (ERH) replaces natural gas as the hot utility, and (b) advanced electrification, which combines ERH and electricity-powered vapor recompression cycles while also redesigning the process heat integration scheme. Under the reference grid scenario, advanced electrification achieves greater emissions reductions (78–90%) than simple electrification (51–55%), reflecting its lower electricity intensity. Despite higher capital investment, advanced electrification yields lower levelized costs than simple electrification and limits cost increases vs the baseline process to 16–23%. This results in carbon abatement costs (CAC) of 31–57 $/tonneCO2 vs ∼170 $/tonne CO2 for simple electrification. Advanced electrification also resolves a cost–emissions trade-off present under simple electrification and the baseline process, making lower-cost, lower-per-pass-conversion layouts preferable on both metrics while also reducing the process's sensitivity to electricity grid conditions. Sensitivity analysis confirms robustness of these findings to changes in unit-level operating conditions as well as electricity price and grid CI variations.