Study on the effect of chemical inhibitors on CO2 adsorption in coal

The injection of carbon dioxide (CO2) into gob contributes to the geological sequestration of CO2. The chemical inhibitors, which are used for fire protection, can promote the sequestration of CO2. High pressure adsorption tests, swelling experiments and scanning electron microscopy were used to analyze the effects of several chemical inhibitors on the CO2 adsorption and on the coal pore structure. The adsorption capacity of CO2 and its pore volume increase after spaying an inhibitor solution. The treatment of coal in an inhibitor solution increases its pore size distribution from 0.4 nm to 0.6 nm in coal. Moreover, pore sizes lower than 0.419 nm increase together with the adsorption capacity of CO2. Based on the swelling experiments, soaking coal in an inhibitor solution induces a swelling effect on the compound, which leads to an increase in the size of its pores and cracks. This increasing trend of the pores and cracks has been verified by a series of adsorption experiments. The results obtained in this paper provide a basis for the development of further applications based on the CO2 storage technology.