Sequestration of CO2 by concrete and natural minerals - current status, future potential, and additional benefits

Abstract

Concrete structures are some of the largest constructions in human civilization. Their manufacture releases CO2 into atmosphere, which is partially readsorbed by standing structures, and further release occurs when they are demolished. Concrete is chemically similar to basaltic minerals, both adsorb CO2 where they are exposed on the earth's surface. Sequestration of CO2 is beneficial to reduce atmospheric concentrations, and thus limit future temperature increases. Therefore, multiple options are being examined for CO2 sequestration. For the first time, we compare the CO2 sequestration capacity of these two materials. We review previous work quantifying CO2 sequestration capacity of both materials and for the first time, compare their potential quantitative roles. Costs of that are compiled, to the extent they have been examined. Costly grinding of these materials to small particle sizes accelerates CO2 sequestration, and mycorrhizae in agricultural soils might reduce the associated costs. Both these materials can improve nutrient status in agricultural soils, and limit acidification from external nitrogen fertilization. Limitations are discussed in terms of land-use and material availability, and soil pH conditions. We call for further experiments with these materials that compare CO2 sequestration and other biogeochemical processes in agricultural systems across climates, carried out especially where such materials are conveniently available.

Keywords

• sequestrations
• co2
• concrete
• basalt
• carbonation