A new CO2 disposal process via artificial weathering of calcium silicate accelerated by acetic acid

A new disposal process for anthropogenic CO: via an artificially accelerate d weathering reaction is proposed to counteract global warming. The process is essentially composed of the following two steps: (1) CaSiO3 + 2CH(3)COOH --> Ca2+ + 2CH(3)COO(-) + H2O + SiO2. (2) Ca2+ + 2CH(3)COO(-) + CO2 + H2O --> CaCO(3)down arrow+ 2CH(3)COOH. Step (1) is the extraction of calcium ions by acetic acid from calcium sili cate, for example, wollastonite rocks. Step (2) is the deposition of calciu m carbonate from the solution of calcium ions by CO2 injection. The Gibbs f ree energy change of each step is negative; the reactions would proceed spo ntaneously without consuming large amounts of energy. The CO2 would be capt ured from the concentrated emission sources such as thermal power plant, an d be disposed of and sequestrated in the form of calcium carbonate. The fea sibility of the proposed process was evaluated through a process design bas ed on the experimental results of the reaction kinetics. The operational en ergy consumption was 20.4 MW for the disposal of CO2 produced by a 100-MW t hermal power plant. (C) 2001 Elsevier Science Ltd. All rights reserved.