Patent ID: 8871176

Claim:
A process for reducing sulfur emission of a sulfur plant, comprising: introducing a H 2 S-containing acid gas into a thermal reaction unit, combusting the H 2 S-containing acid gas to produce SO2, and conducting Claus reaction between H 2 S and SO 2 to produce a first elemental sulfur stream and a process gas, wherein the first elemental sulfur stream is introduced into a liquid sulfur tank; introducing the process gas into a catalytic reaction unit to carry out Claus catalytic conversion to obtain a second elemental sulfur stream and a Claus tail gas, wherein the second elemental sulfur stream is introduced into the liquid sulfur tank; and introducing the Claus tail gas into a tail gas purification unit, wherein the Claus tail gas firstly undergoes hydrogenation to produce a hydrogenation tail gas comprising H 2 S, and introducing the hydrogenation tail gas into an absorption column, wherein H 2 S is absorbed in the absorption column to provide a purified tail gas; introducing a portion of the purified tail gas into the liquid sulfur tank as a stripping gas for degassing the liquid sulfur, wherein the purified tail gas is converted to a waste gas; and introducing the waste gas into the catalytic reaction unit, the tail gas purification unit, or a combination thereof.