Effect of Methane, CO 2 , and H 2 S on the Solubility of Methyl and Ethyl Mercaptans in a 25 wt % Methyldiethanolamine Aqueous Solution at 333 and 365 K

We have investigated the solubility of methanethiol and ethanethiol (methyl and ethyl mercaptans in an aqueous methyldiethanolamine solution (25 wt%) by using static-analytic method at 333 and 365K. The measurements were done for different pressure of methane in the absence of acid gas with individual acid gas present, and with mixture of acid gases present (CO2 and/with H2S). Additional measurement of Henry's law constant were realized by considering gas stripping method. Effect of total pressure (realized by addition of methane) and effect of acid gas loading for a constant total pressure around 7 MPa were studied. The increasing of pressure and acid gas loading increase the apparent Henry's law constant of the mercaptan, highlighting a drop out effect of the mercaptans.