Progress on binding CO₂ in mineral substrates

Based on current estimates of reserves, coal could satisfy even a very much increased world energy demand for centuries, if only the emission of CO₂ into the atmosphere could be curtailed. Here we present a method of CO₂ disposal that is based on combining CO₂ chemically with abundant raw materials to form stable carbonate minerals. A major advantage of this method is that the resulting waste product is thermodynamically stable and environmentally neutral. It is therefore possible to store large quantities permanently with minimal environmental impact and without the danger of an accidental release of CO₂ which has proven fatal in quantities far smaller than contemplated here. The raw materials to bind CO₂ exist in nature in large quantities in ultramafic rocks. They are readily accessible and far exceed what would be required to bind all CO₂ that could possibly be generated by burning the entire fossil fuel reserves. In this paper we outline a specific process that we are currently investigating. Our initial rough cost estimate of about 3¢/kWh is encouraging. The availability of a CO₂ fixation technology would serve as insurance in case global warming, or the perception of global warming, would cause severe restrictions on CO₂ emissions. If the increased energy demand of a growing world population is to be satisfied from coal, the implementation of such a technology would be unavoidable. Published by Elsevier Science Ltd.