Study of hydrogen sulfide absorption with diethanolamine in methanolic aqueous solutions

Abstract

The sulphur compounds are removed by various processes, among which that corresponding to the gas absorption in specific liquid solutions. This absorption is carried out by physical, chemical solvents and currently by mixing both in the so called hybrid solvents. In this work, hydrogen sulphide (H2S) absorption in a hybrid solvent containing aqueous Di-Ethanol-Amine (DEA) dissolved in methanol have been studied extensively in a modified Lewis cell reactor. Experiments have been achieved in an extended range of temperature, 313-353 K and with two mixtures (50% water, 30%DEA, 20% Methanol), (40% water, 40% DEA, 20% methanol). Through these experiments, three parameters affecting the absorption of hydrogen sulfide (temperature T, loading rate (mol H2S/mol DEA) and mass fraction %) were studied. Absorption is accelerated by raising the temperature while it is penalized by the increase in the loading rate. The absorption rate increases as the mass fraction of DEA varies from 30% to 40% to achieve an optimum loading rate (=0.25(1)at T =333 K and = 0.50 at T=353 K) for hich the absorption rate remains practically unchanged.