Hydrogenation to convert CO 2 to C1 chemicals: Technical comparison of different alternatives by process simulation

Carbon dioxide (CO 2 ) conversion by catalytic reaction with hydrogen to produce different C1 chemicals is a promising strategy in view of the development of a sustainable chemical industry. In this work, two CO 2 hydrogenation routes are investigated in detail, respectively syngas and formic acid syntheses. Starting from published experimental reaction data, simulation models based on a kinetic analysis were developed and implemented in Aspen Plus process simulator. The two processes are analyzed according to a number of selected technological indicators, comprising CO 2 conversion, specific H 2 consumption, product yield, energy duties, and carbon emissions. To extend our study, three additional CO 2 conversion pathways are considered, respectively methanol, methane, and urea syntheses, whose technological performances were retrieved from similar studies available in the scientific literature. Under the assumption that H 2 is available from renewable sources, our results highlight that CO 2 conversion routes towards fuel compounds (ie, syngas and methane) look particularly appealing from the energy balance point of view. If non‐renewable energy is used to produce H 2 , the actual environmental benefits (in terms of net CO 2 emissions) strongly depend on the country‐specific carbon intensity for electricity generation.