Carbon dioxide and sulfur dioxide capture from flue gas by gas hydrate based process

Abstract

The CO2 and SO2 capture from the simulated flue gas simultaneously by gas hydrate process were experimentally studied using tetra-n-butyl ammonium bromide (TBAB) as the hydrate formation promoter in this work. The effects of initial pressure, SO2 enrichment, the ratio of gas and liquid and TBAB concentration on CO2 and SO2 capture have also been studied. The results indicate that about 95% of SO2 in flue gas can be removed by gas hydrate capture process, but the vast majority of SO2 are captured by dissolution, and gas hydrate formation has very little effect on SO2 removal. SO2 enrichment in solution increases SO2 concentration in residual gas. The intial pressure, TBAB concentration and the ratio of gas and liquid volume has very small effect on SO2 capture, but have some effects on CO2 capture. Both the dissolution and hydrate formation have a role on CO2 capture. The CO2 concentration in residual gas reduces to about 8 mol% after the hydrate capture, and the S.Fr.CO2 reaches above 60%, and the S.F.CO2 reaches around 8.