A general rate equation theory for non- and catalytic coupling gas-solid reactions and its application to sorption-enhanced water gas shift

Sorption-enhanced water gas shift (SEWGS) involves the catalytic WGS reaction of CO with H2O and the noncatalytic gas-solid carbonation reaction of CO2 with CaO. This work proposes a first-principal rate equation theory for non- and catalytic coupling gas-solid reactions. The theory starts from quantum chemistry calculation and extends to larger scales to predict SEWGS experiments conducted in the reactor result without any empirical hypothesis. The coupling mechanism of non- and catalytic reactions is illustrated in a mesoscopic way, based on which the kinetic transition behavior and morphology change on the catalyst surface for WGS can be obtained. The hierarchical framework bridges the scale gap between elementary reactions and pilot plants and the prediction results of and gas profile at the exit of the bubbling bed and carbonation conversion are validated by experiments. The multiscale kinetics is promising to apply to non- and catalytic coupling gas-solid reaction kinetics studies.