Integrated sulfur recovery and hydrogen production process

The present invention of H2 production, SO2 and H2SO4 production steps introduces using the Sulfur-Iodine (S-I) thermochemical cycle and the acid gas burner to process the acid gases that are processed in the prior arts of Claus sulfur recovery and tail gas treating unit, with combinations of necessary modifications to the prior arts wherein, a portion of the acid gases feed is routed to the present invention acid gas burners wherein, first the sulfur compounds, and the ammonia gases are combusted with air or oxygen and without using any fuel gas and then the combusted gases in contact with Iodine produces hydrogen and the remaining of SO2 is converted to the sulfuric acid or is sent to other units to produce other products, the Iodine as the catalyst agent is recovered and re-used in the present invention:

• step 1) providing acid gas stream(s) from the amine acid gas and sour water stripping gas that is normally processed in prior arts of Claus sulfur recovery unit into properly designed acid gas burner or staged burners, receiving air, enriched air or oxygen and without any fuel gas to combust all the combustible components to SO2, and other inert gases nitrogen, CO2, N2, water and excess oxygen operating at a very high temperature;
• step 2) when the gases are fully combusted in the acid gas burner(s), the combusted gas containing, SO2, CO2, N2, H2O, O2 and SO3 or H2SO4 is sent to the waste heat boiler to generate HP steam or to H2SO4 vaporizer exchanger to recover the heat and to cool of the combusted gas and vaporize a slim stream of H2SO4;
• step 3) the combusted gas mixture from step 2 is further cooled off and quenched in the tube side of a exchanger and is sent to a reactor;
• step 4) in the shell side of the step 3 exchanger, I2, HI and water is added to heat up the mixture and the chemical reaction occurs and H2 and 12 is produced then the mixture is sent to a 3-phase separator to condense H2O which is recycled to step 5, wherein, H2 is separated from I2, and H2 is one of the product from the present innovation;
• step 5) wherein, the cooled gas mixture, SO2, O2, N2, H2O and SO3 has two choices;
• (a) a portion of the stream is sent to other units as SO2 product for other applications as valuable fertilizer or other products or SO2 is liquefied;
• (b) a portion or the full stream is sent to the reactor with I2 and recycled H2O from step 4, to have another reaction at 120 C;
• wherein, SO2 reacts with I2 accordance to equation of to produce sulfuric acid and HI;
• Step 6) wherein, the cooled gas from the reactor enters a quench column where N2 and CO2 is separated from the mixture, and is sent to CO2 removal or CO2 liquefaction unit, the bottom of the quench column consists of H2SO4, H2o, IH and HI flows to liquid-liquid contactor to separate H2SO4 from IH and I2 and recycled to step 4;
• Step 7) wherein, H2SO4 from step 6, bottom of the liquid-liquid contactor is sent to a sulfuric acid concentration to concentrate the H2SO4 as another product on the present invention by using steam reboiler as desired and the water is removed.
• and wherein, said process produces H2, SO2 and H2SO4 as the products mainly reduce importing of hydrogen and sulfuric acid to a facility and wherein, SO2 emission is eliminated, while CO2 emission is reduced and recovered and sent to other unit.