Systematic comparison of natural and engineering methods of capturing CO2 from the air and its utilization

Abstract

The rising CO2 concentration in the atmosphere calls for not only the decarbonization of our lifestyle but also the removal of CO2 to meet the sustainable development goals. In this work, a comprehensive techno-economic comparison based on systematic process design of CO2 capture technologies from the air is performed. Biomass and direct air capture (DAC) are considered as well as the further utilization of CO2. A common final product, methanol, is selected for easier comparison. Six different biomasses are considered, including energy crops, forests, and agriculture. Four biomass gasification routes are evaluated to produce methanol. Two direct air capture technologies are followed by CO2 hydrogenation. Hydrogen is produced by splitting water using solar and/or wind energy. The current status of the technologies gives biomass an advantage as carbon capture technology with production and investment costs ten times lower, due to the high price of the renewable energy collection for the operation of the fans. However, the area required for growing biomass, except in the case of residues, and the total amount of water consumed, favors the engineered alternative, DAC. The investment and production costs depend on the location and the technology development.