Carbonation of magnesium silicate mineral using a pressurised gas/solid process

Carbon dioxide mineral sequestration is not as widely advocated as CO₂ sequestration by other means such as underground storage alternatives, yet it possesses properties (capacity, permanency, energy economy) that can not be matched by other options. In this paper, our findings and results since GHGT-8 as well as current activities and near-future plans regarding CO₂ mineral carbonation are presented. The focus lies on the use of fluidised bed (FB) reactors for the carbonation of magnesium silicates via magnesium oxide or magnesium hydroxide intermediates, at temperatures and pressures up to 600°C, 100 bar (allowing for both sub- and supercritical conditions for CO₂), supported by earlier experiments using pressurised thermogravimetric analysis (PTGA). In addition, as the production of reactive magnesium from silicate mineral is not straightforward, it receives special attention, and first results of magnesium hydroxide production from serpentine using different methods are presented.