Process and apparatus for treatment of a gas containing hydrogen sulfide and sulfur dioxide and comprising a step for the removal of solid byproducts

摘要

By-product layer lies between liquid sulfur and separated solvent. Liquid fraction containing solid by-products is removed at the layer level and subjected to specified treatment, to give a mainly by-product flow and a by-product-free solvent flow. Effluent gas free from H2S and SO2 is recovered. Liquid sulfur is separated from solvent by liquid-liquid decantation. Treatment of the liquid fraction containing solid by-products involves carrying out at least one of the following operations at 120-180 degrees C: (a) treatment with an aqueous phase such as water at a temperature, pressure (preferably between atmospheric pressure and 1.5 MPa), and flow rate sufficient to solubilize at least the major part of the solid by-products in the aqueous phase, and to obtain liquid-liquid separation between the aqueous phase and an organic phase containing most of the removed solvent, and/or (b) filtration treatment, and/or (c) collection on a solid support of by-products in order to recover at least two phases: a phase consisting of solvent depleted in solid by-products and a phase discharged from regeneration of the collection bed and containing most of the by-products. Independent claims are given for: (i) a device used for implementation of the process; and (ii) application of the process for treatment of effluent from Claus units for treatment of hydrogen sulfide discharged from natural gas purification and petrol refining operations.