Options for delivering CO2 in P2G systems producing synthetic fuels

Power-to-gas (P2G) technologies producing synthetic fuels have the potential to address the issue ofintermittency of electricity from solar and wind farms, and simultaneously contribute to lower CO₂concentration in the atmosphere. However it requires, among others, judicious technical selection ofappropriate CO₂ capture and delivery technologies. For example, compared to CCS, where the purity ofthe product CO₂ gas is mostly dictated by transportation and subsequent storage requirements, in P2Gsystem producing SNG the catalyst to be used in the Sabatier conversion of CO₂ to CH₄ is sensitive totrace contents of S and metal impurities. This is also true for Fischer–Tropsch based synthesis of otherhydrocarbons.More than 100 technical articles were reviewed to understand CO₂ capture technologies includingcapture from air that have received attention within the last decade. The goal is to determine theapplicability of these technologies to P2G systems producing synthetic fuels. The review includestechnologies such as absorption, adsorption, and low temperature CO2 capture. In addition, top sourcesof renewable CO₂, such as biomass combustion, are also presented.An easy-to-understand visual summary on the energy requirements, recovery, CO₂ product purity,hydrophobicity issues and technology development status is presented. More importantly, the quality ofthe product CO₂ from the said technologies is assessed. From these properties an appropriate CO²capture and delivery technology is proposed for the production of synthetic fuel.