Simultaneous absorption of carbon dioxide and hydrogen sulfide into aqueous blends of 2-amino-2-methyl-1-propanol and diethanolamine

This work presents an experimental and theoretical investigation of the simultaneous absorption of CO2CO2 and H2SH2S into aqueous blends of 2-amino-2-methyl-1-propanol (AMP) and diethanolamine (DEA). The effect of contact time, temperature and amine concentration on the rate of absorption and the selectivity were studied by absorption experiments in a wetted wall column at atmospheric pressure and constant feed gas ratio. The diffusion–reaction processes for CO2CO2 and H2SH2S mass transfer in blended amines are modeled according to Higbie's penetration theory with the assumption that all reactions are reversible. The blended amine solvent (AMP+DEA+H2OH2O) has been found to be an efficient mixed solvent for simultaneous absorption of CO2CO2 and H2SH2S. By varying the relative amounts of AMP and DEA the blended amine solvent can be used as an H2SH2S-selective solvent or an efficient solvent for total removal of CO2CO2 and H2SH2S from the gas streams. Predicted results, based on the kinetics-equilibrium-mass transfer coupled model developed in this work, are found to be in good agreement with the experimental results of rates of absorption of CO2CO2 and H2SH2S into (AMP+DEA+H2OH2O) of this work.