CO_2 Mitigation Potential of Mineral Carbonation with Industrial Alkalinity Sources in the United States

摘要

The availability of industrial alkalinity sources is investigated to determine their potential for the simultaneous capture and sequestration of CO_2 from point-source emissions in the United States. Industrial alkalinity sources investigated include fly ash, cement kiln dust, and iron and steel slag. Their feasibility for mineral carbonation is determined by their relative abundance for CO_2 reactivity and their proximity to point-source CO_2 emissions. In addition, the available aggregate markets are investigated as possible sinks for mineral carbonation products. We show that in the U.S., industrial alkaline byproducts have the potential to mitigate approximately 7.6 Mt CO_2/yr, of which 7.0 Mt CO_2/yr are CO_2 captured through mineral carbonation and 0.6 Mt CO_2/yr are CO_2 emissions avoided through reuse as synthetic aggregate (replacing sand and gravel). The emission reductions represent a small share (i.e., 0.1%) of total U.S. CO_2 emissions; however, industrial byproducts may represent comparatively low-cost methods for the advancement of mineral carbonation technologies, which may be extended to more abundant yet expensive natural alkalinity sources.