CO2Fix: An approach to assess CO2 fixation potential of CCU reaction pathways

Abstract

In this work we present a simple, yet powerful, metric for estimating the potential of a CCU reaction pathway to fix CO₂. The CO2Fix metric is determined by using a model that accounts for various process variables and parameters that influence the ability of the reaction to convert CO₂ in addition to its propensity to produce CO₂ through the energy requirements of the process. The CO2Fix metric in this work accounts only for the direct CO₂ emissions and indirect CO₂ emissions related to the reaction portion of a CCU process. We demonstrate the use of the model to estimate the CO2Fix in two case studies representing common CCU reactions: dry reforming of methane (DRM) and CO₂ hydrogenation to methanol. When using natural gas-powered energy, and under the same process assumptions, the CO2Fix was estimated to be 1.1 and 3.9 for the DRM and CO₂ hydrogenation reactions respectively.