Patent ID: 8623308

Claim:
A process for removing mercaptans from a feed gas stream comprising natural gas or inert gas having a mercaptans concentration of up to 40 vol %, the process comprising the steps of: (a) passing said feed gas stream to a gas treating unit, wherein said gas treating unit includes a mercaptan adsorbent bed, said adsorbent bed consisting essentially of a mercaptan adsorbent material selected from the group consisting of silica, silica gel, alumina, silica-alumina, and molecular sieve, to thereby provide a mercaptan adsorbent material loaded with mercaptan and to yield therefrom a gas stream having a mercaptans concentration of less than 5 ppmv; (b) ceasing said passing of said feed gas stream to said gas treating unit, and, thereafter, contacting said mercaptan adsorbent material loaded with mercaptan with an inert gas stream at an elevated temperature or reduced pressure to transfer mercaptan from said mercaptan adsorbent material loaded with mercaptan to said inert gas stream to thereby yield from said gas treating unit a first gas stream comprising mercaptans and at least 80% of gases selected from the group of helium in the periodic table, nitrogen and hydrocarbonaceous gases, wherein the concentration of CO 2 in the first gas stream is below 8 vol %; (c) contacting said first gas stream with a hydrodesulphurisation catalyst in the presence of hydrogen in a hydrodesulphurisation unit to obtain a second gas stream comprising inert gas, which is depleted of mercaptans and enriched in H 2 S; and (d) removing H 2 S from the second gas stream in a H 2 S removal unit which comprises a H 2 S adsorbent bed which further comprises titania to obtain a purified gas stream comprising inert gas, which is depleted of H 2 S and mercaptans to a level of below 1 ppmv.