CO2 capture and utilization (CCU) by integrating water electrolysis, electrified reverse water gas shift (E-RWGS) and methanol synthesis

Carbon capture and utilization has a significant role in the transition to a sustainable and decarbonized economy. In this work, we present a technical analysis, completed with AspenPlus, for examining the fea-tures of an innovative process scheme designed for converting CO2 into synthetic methanol by combining: i) a water electrolysis system, ii) an electrified reverse water gas shift reactor, and iii) a methanol synthesis reactor. The use of an electrically heated reactor avoids the CO2 emis-sions associated to a furnace heated reactor and allows the achievement of high reaction temperatures (950 degrees C). Moreover, the utilization of an electrified reverse water gas shift reactor improves the overall energy efficiency and allows process simplification with respect to the currently examined process schemes. In addition, we show that, if the process is fed with CO2 obtained from a biogas plant, negative CO2 emission are produced when the carbon intensity of the electricity remains below 120 gCO2/kWh.

Automated summary

This study presents an innovative process scheme for converting CO2 into synthetic methanol, which combines an electrified reactor and a reverse water gas shift reactor, achieving high energy efficiency and process simplification. Negative CO2 emissions can be achieved when CO2 is sourced from a biogas plant and the carbon intensity of the electricity remains below 120 gCO2/kWh.