TH36600B - The process of removing hydrogen sulfide from the gas stream. - Google Patents

Abstract

DC60 (24/11/54) Processes and systems for removing hydrogen sulfide from loud gas streams. For example, natural gas, a high sulfur gas stream containing H2S, is exposed to anhydrous solution It is an insoluble absorbent liquid containing organic solvent for sulfur Sulfur element dissolved organic base to catalyze the reaction. and organic solvents, which are suitable for maintaining the solubility of intermediate polysulfides that may separate when they are formed during the processing of polysulfides. process Hydrogen sulfide (H2S) gas is absorbed in this liquid. and then reacts with sulfur that is dissolved in the presence of a base to form polysulfide molecules. This solution is then sent to the reactant where there is sufficient resting time. to be prepared by the polysulfide reaction to the level of completeness as desired From the reagent the solution flows to the regenerator, where the solution is oxidized (eg by exposure to air) to form dissolved sulfur and water. The solution temperature is then lowered. To form sulfur crystals that can be removed by precipitation by gravity itself, filtration, centrifugation or other separation methods, after which the sulfur crystals have been removed. The dissolved sulfur remains in the enough solution Therefore, when this solution is heated again and was brought back to the absorber again. The amount of sulfur contained It is sufficient to react with the incoming H2S gas, the process and the system for removing hydrogen sulfide from the gas stream loudly. one example Natural gas, a high sulfur gas stream containing H2S to be exposed to anhydrous solution It is an insoluble absorbent liquid containing organic solvent For sulfur elements, dissolved sulfur elements, organic bases to stimulate the reaction. and dissolved organic substances, which are suitable substances for preservation. of the solubility of median polysulfides that may be separated when they are formed during the processing of the process. Hydrogen sulfide (H2S) gas is absorbed in these items. and then reacted with the sulfur that was dissolved in the presence of a base to form polysilphide molecules The solution is then sent to the reaction tank, where there is sufficient holding time to provide with the polysulphide reaction to the level tank. complete as desired From the reaction tank the solution flows to the regenerator, where the solution is oxidized (eg by exposure to air) to form dissolved sulfur and water. The temperature of the solution is then lowered. lower to form sulfur crystals that can be removed by spontaneous gravity precipitation, filtration, centrifugation or other separation methods, after which the sulfur crystals have been removed The dissolved sulfur remains in the enough solution Therefore, when this solution is heated again and was brought back to the absorber again. The amount of sulfur present is sufficient to react with the incoming H2S gas.

Claims (14)

1. The process of removing H2S from a gas stream consists of the following steps: (a) contact of the gas stream containing H2S with an adsorbent fluid containing an anhydrous solvent with dissolved sulfur and a base primarily composed of tertiary amines, with sufficient density and concentration to drive the conversion reaction that adsorbs H2S into the dissolved sulfur to form non-volatile polysulfides soluble in the adsorbent fluid; (b) conversion of the non-volatile polysulfides soluble in the adsorbent fluid into the remaining dissolved sulfur in the fluid through contact of the fluid from step (a) with the oxidizing gas; (c) conversion of at least a portion of the dissolved sulfur in the fluid from step (b) into solid sulfur particles; and (d) separation of the solid sulfur from the fluid from step (c). 2. The process under claim 1 in which the aforementioned anhydrous solvent is insoluble in water. 3. The process under claim 2 shall include a dissolving agent to maintain the solubility of the polysulfide intermediates that may be separated during the process. 4. The process under claim 3 continues to include the reuse of the sulfur-separated adsorbent liquid for continued contact with the H2S-containing gas stream. 5. The process pursuant to claim 3, where an anhydrous solvent has a sulfur solubility ranging from approximately 0.05 to 3.0 g/mol of sulfur per liter of solution. 6. The process pursuant to claim 3, whereby such base shall be selected from groups consisting of 2-)dibutylamino) ethanol, N-methyldicyclohexylamine, N-methyldiethanolamine, tributylamine, dodikyldimethylamine, teradekyldimethylamine, hexadekylmethylamine, and mixtures thereof. 7. The process pursuant to claim 3, whereby the solute shall be selected from a group consisting of benzyl alcohol, benzichloro3-phenyl-1-propanol tri(ethylene glycol), alkylaryl polyether alcohol and mixtures thereof. 8. The process pursuant to claim 3, whereby the anhydrous solvent shall be selected from a group consisting of 1,2,3,4 tetrahydronaphthalene, N,N-dimethylaniline, diphenyl ether, dibenzyl ether, partially hydrogenated terphenol, diphenyl diphenol, partially hydrogenated ethane, and mixtures thereof. 9. The process under claim 3 in which the precipitated sulfur is purified by solvent washing to remove any remaining small amount of anhydrous solvent. 10. The process under claim 3 in which the sulfur salt byproduct is removed from an anhydrous solvent by washing such solvent with water or an aqueous alkaline solution when such solvent is not aqueous. 11. The process under claim 4 in which at least the dissolved sulfur portion is converted into a solid by cooling the adsorbent liquid that occurs after the oxidation of the polysulfide to a temperature at which the precipitation of the solid sulfur particles occurs. 12. The process under claim 11 where the adsorbent liquid is heated to a temperature of approximately 15°C to 70°C before cooling. 13. The process pursuant to claim 12, in which the adsorbent liquid is cooled to 5°C or 20°C to induce the precipitation of the sulfur. 14. The process under claim 11 where sufficiently dissolved sulfur remains in the adsorbent fluid formed after the separation of the precipitated sulfur, which, when such solution is returned to the adsorbent for reuse in the process, will have sufficient sulfur available to react with the incoming H2S gas.