Membrane process for H2 recovery from sulfur recovery tail gas stream of sulfur recovery units and process for environmentally greener sales gas

A system for treating an acid gas contaminated stream to control emissions, generate hydrogen gas, or generate a greener natural gas, the system comprising:

• a sulfur recovery unit, operable to convert sulfur compounds in an acid gas stream to elemental sulfur and further to generate a sulfur recovery unit waste stream;
• a tail gas treatment reheater fluidically connected to the sulfur recovery unit, operable to heat the sulfur recovery unit waste stream to create a heated sulfur recovery unit waste stream;
• a tail gas treatment reactor fluidically connected to the tail gas treatment reheater, operable to reduce sulfur compounds in the heated sulfur recovery unit waste stream to hydrogen sulfide, to generate a tail gas stream;
• a quench tower fluidically connected to the tail gas treatment reactor, operable to reduce the temperature of the tail gas stream, to generate a sour water stream and a quench tower overhead stream;
• an H2 selective membrane unit fluidically connected to the quench tower, comprising an H2 selective membrane, operable to selectively remove hydrogen from the quench tower overhead stream through the H2 selective membrane to generate an H2 rich stream and an H2 lean stream;
• and
• an H2S removal unit fluidically connected to the H2 selective membrane unit, operable to absorb hydrogen sulfide from the H2 lean stream with a solvent and configured to regenerate the solvent, to generate an H2S lean stream and an H2S rich recycle.

A system for treating an acid gas contaminated stream to control emissions, generate hydrogen gas, or generate a greener natural gas, the system comprising:

• a sulfur recovery unit, operable to convert sulfur compounds in an acid gas stream to elemental sulfur and further to generate a sulfur recovery unit waste stream;
• a tail gas treatment reheater fluidically connected to the sulfur recovery unit, operable to heat the sulfur recovery unit waste stream to generate a heated sulfur recovery unit waste stream;
• a tail gas treatment reactor fluidically connected to the tail gas treatment reheater, operable to reduce sulfur compounds in the heated sulfur recovery unit waste stream to hydrogen sulfide, to generate a tail gas stream;
• a quench tower fluidically connected to the tail gas treatment reactor, operable to cool the tail gas stream, to generate a sour water stream and a quench tower overhead stream;
• an H2S removal unit fluidically connected to the quench tower, operable to absorb hydrogen sulfide from the quench tower overhead stream with a solvent and configured to regenerate the solvent, to generate an H2S lean stream and an H2S rich recycle;
• and
• an H2 selective membrane unit fluidically connected to the H2S removal unit, comprising an H2 selective membrane, operable to selectively remove hydrogen from the H2S lean stream through the H2 selective membrane to generate an H2 rich stream and an H2 lean stream.