Patent ID: 7780933

Claim:
A method of refining natural gas containing at least hydrogen sulfide and mercaptan as impurities by removing the impurities from the natural gas, characterized in that the method comprises: a first absorption step of treating natural gas by means of a chemical absorption method using an amine-containing solution to mainly remove hydrogen sulfide and carbon dioxide; an adsorption step of flowing the natural gas from the first absorption step through a packed bed of a molecular sieve to mainly remove mercaptan; a recovery step of recovering sulfur compounds by converting the hydrogen sulfide removed in the absorption step into sulfur by means of a Claus process; a regeneration step of desorbing the mercaptan adsorbed on the molecular sieve in the adsorption step using heated gas, creating a regeneration exhaust gas; and a reaction step of converting the mercaptan in the regeneration exhaust gas exhausted from the regeneration step into hydrogen sulfide, creating a reaction step exhaust gas; and that the reaction step is conducted by injecting steam or water at a ratio of H 2 O/S=1 to 5 (mol ratio) relative to the sulfur in the regeneration exhaust gas in the presence of a catalyst under the conditions of a temperature level of 250 to 400° C. and a pressure level of 1 to 10 MPa; wherein the process precludes tail gas treatment, and the sulfur recovery ratio is not lower than 98%.