Comprehensive analysis of two catalytic processes to produce formic acid from carbon dioxide

摘要

Carbon utilization (CU) based formic acid (FA) process is a promising option to reduce carbon dioxide (CO2) causing global warming but energy intensive resulting in a negative income effect on energy consumption. In the literature, catalytic conversion of CO2 to FA at low concentrations is focused and limited to recovery of FA with a high purity. This study presents two commercial-scale processes for catalytic production of formic acid (FA) from CO2, and conducts economic, energy and environmental analysis of them. Process B that uses an Au/TiO2 catalyst has a higher conversion by 3 mol% to 84 mol% than Process A that uses a Ru-Ph catalyst. Moreover, after catalytic conversion of CO2, Process B uses an additional amine shift reaction to recover FA with low energy consumption. Simulation of process design including CO2 conversion and separation of FA shows that Process B has a higher energy efficiency by 24.3% to 69.0% compared to Process A. However, Process A has a much lower reaction time (T-R) than Process B, so the minimum selling price of FA (US$ 1,029/t(FA)) for Process A is more cost-competitive than Process B (US$ 1,037/t(FA)) with the current petroleum-based approach. In contrast, environmental analyses show that Process B has a higher potential by 0.3 t(CO2)/t(FA) to reduce CO2 emissions. If feasible positive assumptions (reduced T-R; received carbon credits) can be met, Process B will also be techno-economically viable.