PROCESS AND PLANT FOR THE TREATMENT OF H2S

The purpose of the present invention is to provide a process and related plant for recovering H₂ from H₂S in conventional chemical-physical washing and hydro-desulphurisation units. Specifically, the invention offers an alternative and improved treatment for H₂S compared to conventional plants that rely solely on washing/hydro-desulphurisation and sulphur recovery units. The main objective is to introduce an innovative process and plant technology that replaces elemental sulphur recovery from H₂S with hydrogen recovery. Another goal is to provide a plant unit that can be quickly and inexpensively integrated into existing conventional plants, minimizing modifications and downtime. The process for treating H₂S and obtaining an H₂-enriched stream includes the following steps: Decontamination of a process/feed stream from H₂S or sulphur using chemical/physical washing or hydro-desulphurisation. Conveyance of the gaseous waste stream containing separated H₂S to one or more H₂S treatment units. Heating and high-temperature decomposition of H₂S via thermal or thermo-catalytic means to form an H₂-enriched stream. Cooling the H₂-enriched stream and condensing elemental sulphur. Separation of condensed sulphur from the H₂-rich stream. Optional diversion of a portion of the H₂S-containing waste stream to a sulphur recovery unit. The plant comprises: A first unit for chemical-physical washing or hydro-desulphurisation. A second unit for sulphur recovery from H₂S (optional). A third unit for hydrogen recovery from H₂S. The first and second units are connected by a line to convey the waste stream, while the third unit taps into this line to divert a portion of the stream. Alternatively, the third unit may directly receive the waste stream from the first unit, bypassing the sulphur recovery unit entirely. The first unit can be a conventional washing-stripping unit, hydro-desulphurisation and adsorption unit, or a combination thereof. The second unit (if present) typically includes a furnace and catalytic reactors to convert H₂S into elemental sulphur. The third unit consists of: A reactor to decompose H₂S into H₂ and sulphur. Heat exchangers to cool the H₂-enriched stream and condense sulphur. Separators to isolate H₂ from condensed sulphur. Optional additional separators to purify the H₂ stream further. For plants with both sulphur and hydrogen recovery units, flow control valves regulate the distribution of the H₂S stream between the two processes. This design allows for flexible implementation in new plants or retrofitting of existing ones with minimal modifications. In summary, the invention enhances the economic viability and operational flexibility of H₂S treatment plants by prioritizing hydrogen recovery over traditional sulphur production.