Abstract

This report focuses on the combined capture and storage of multiple gases (CO2 and at least one other gas) from processes that use or treat fossil fuels. It concentrates on coal-based power systems, although many of the issues associated with co-capture and storage from power systems would apply to other fossil fuel-related processes. The potential benefits of co-capture are associated with lower costs for capture of the combined stream of gases, and desirable changes in geochemistry which may improve injectivity and even ‘self-seal’ small underground fissures. However, there are a number of concerns about co-capture and storage.

Some relate to the handling and transport of liquid or supercritical mixed fluids that pose greater health and safety risks than relatively pure CO2 streams, and the potential for the more acidic co-capture mixtures to lead to undesirable chemical reactions near the injection point, including reactions with the steel well pipe and well completion cements.

January 2010