Carbon capture and storage in South Africa

Abstract

Abstract A coal based energy economy and an increasing coal based energy infra-structure bestows on South Africa a high per capita carbon dioxide emission rate. With few other economically exploitable energy resources, and in common with similarly placed countries, such emissions are likely to continue, even in spite of renewable energy programmes and energy efficiency measures. Consequently, South Africa is investigating the use of carbon capture and storage as a green-house gas emission mitigation measure. It has been shown that of the more than 400 million tonnes of carbon dioxide emitted per year, approximately 60% is sequestratable —that is, point sources and capturable. Of that, nearly 30 million tonnes per year of ∼95% pure carbon dioxide is emitted by the synthetic fuel industry. It is therefore likely that any envisaged carbon capture and storage project in South Africa is most likely to make use of the almos t pure carbon dioxide stream emanating from the synthetic fuel plants—the capture element that comprises approximately half the cost having already been done. Preliminary studies and the subject of this paper have indicated that at least 100 gigatonnes of geological storage could be available—more than four times the capacity required to store 240 million tonnes per year for 100 years. Most of that pertains to deep saline aquifers, with some extra prospects of depleted gas fields and enhanced coal-bed methane recovery. Potential storage sites and their characterisation will be addressed in the form of a carbon geological storage atlas that is scheduled for completion by the end of 2009. Following that, it is contemplated that a small-scale demonstration project [say 10,000 tonnes per year] may be undertaken in order for local scientists and engineers to obtain first hand experience in this technology and to prove-up local geological formations. In order to develop capacity, both human and technical, is this relative new field, a Centre for Carbon Capture and Storage is to be established in the South Africa National Energy Research Institute.