Process for deep contaminent removal of gas streams

A process for removing sulfur-containing contaminants from a gas stream, the process comprising the steps of:

• (a) providing a gas stream comprising natural gas, hydrogen sulfide, organic sulfur compounds and carbon dioxide to a first absorption unit, resulting in a hydrogen sulfide lean gas stream and a hydrogen sulfide rich absorbent;
• (b) providing the hydrogen sulfide lean gas stream to a second absorption unit, resulting in a cleaned gas stream and an absorbent rich in organic sulfur compounds and in carbon dioxide;
• (c) providing a first regenerator with the hydrogen sulfide rich absorbent from the first absorption unit, to obtain a lean absorbent and a hydrogen sulfide rich gas stream;
• (d) providing the hydrogen sulfide rich gas to a Claus unit comprising a Claus furnace and a Claus catalytic stage to convert the hydrogen sulfide to obtain sulfur and a Claus tail gas;
• (e) providing a second regenerator with the absorbent rich in organic sulfur compounds and in carbon dioxide to obtain a lean absorbent and a gas stream rich in organic sulfur compounds and in carbon dioxide;
• (f) fully oxidizing all sulfur species of the gas stream rich in organic sulfur compounds and in carbon dioxide to obtain a sulfur dioxide rich gas stream;
• (g) cooling of the sulfur dioxide rich stream to obtain steam, water and a cooled sulfur dioxide rich gas stream;
• (h) providing a third absorption unit with the sulfur dioxide rich gas stream to obtain a sulfur dioxide rich absorbent and sulfur dioxide lean gas stream;
• and
• (i) providing a third regenerator with the sulfur dioxide rich absorbent from the third absorption unit, to obtain a lean absorbent and a purified sulfur dioxide gas stream.