Validation on carbon dioxide hydrate formation through analysis on the solubility of CO2 in water using Henry’s law and the experimental pressure-time curve

Abstract

A rise of 2 ˚C in the Earth’s temperature is likely to occur when the concentration of carbon dioxide (CO2) in the atmosphere reaches approximately 450 ppm. CO2 emissions are closely related to the continual use of fossil fuels. In order to make fossil fuels sustainable, carbon capture and storage (CCS) is required to reduce CO2 emissions. CO2 hydrate (CO2:6H2O) formation has been investigated as a way to capture CO2. The formation of hydrate in this work was experimentally investigated in batch mode inside a vertical fixed-bed reactor (FBR), also known as high-pressure volumetric analyser (HPVA). Standard silica gel with an average particle size of 200–500 μm, mean pore size of 5.14 nm, a pore volume of 0.64 cm3/g, and a surface area of 499 m2/g was used as a porous medium. The presence of hydrate in FBR was justified by using graphic methods. The solubility of CO2 in water using Henry’s law and the experimental pressure–time (P-t) curve were analysed to determine the formation of hydrate. Hydrate formation was confirmed when the mole fraction of CO2 dissolved in water exceeded the Henry’s law value as well as a two-stage pressure drop in the experimental P-t curve.