Mineral sequestration of CO2 and recovery of the heat of reaction
Olaf Schuiling
Dept Earth Sciences - Geochemistry, Faculty Geosciences, Utrecht University
E-mail: schuiling@geo.uu.nl
http://www.geo.uu.nl/Research/Geochemistry/O_Schuiling.html
Abstract
Sequestration of CO2 is the most direct way of combating the excessive greenhouse effect. Sequestration in mineral form is still in its infancy, because dry carbonation of common Mg-or Ca-silicates is unsuccessful. Natural examples show that wet sequestration, combining hydration and carbonation is more successful. I will explore several approaches, either in situ in dunite massifs (olivine-rich rocks), or by reacting crushed olivine off site in contained spaces with the off gases of thermal plants. The reaction produces a large amount of heat, which can be recovered as high enthalpy steam. It can only be applied to large volumes of olivine, as the heat losses become unacceptably high in small systems with a high surface to volume ratio. One possibility would be to fill half of abandoned deep opencast mines with ground olivine and cover it by overburden. In the bottom part a mixture of hot CO2 and steam is injected.