The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 06, 1978
Filed:
Sep. 17, 1976
Kenneth Francis Butwell, Newburgh, NY (US);
Union Carbide Corporation, New York, NY (US);
Abstract
A continuous process for the selective absorption of hydrogen sulfide from a feed gas comprising an acid gas mixture of carbon dioxide and hydrogen sulfide is provided which comprises counter-currently contacting the feed gas with an aqueous alkanolamine solution in an absorption zone having from two to ten separate stages, contacting the feed gas in each stage with lean aqueous alkanolamine solution and withdrawing rich aqueous alkanolamine solution from the bottom of each stage, in each stage maximizing the equilibrium approach between the hydrogen sulfide in the gas and liquid phases and minimizing the equilibrium approach between the carbon dioxide in the gas and liquid phases, and maintaining the rich solution loading in each stage within the range from about 0.1 to about 0.3 mole of acid gas per mole of alkanolamine. The absorption zone is operated in combination with a stripping zone to which rich aqueous alkanolamine solution is passed and in which lean solution is generated. The particular multi-stage absorption process of the invention allows for the recovery as stripping zone overhead of gaseous product in which the combined molar ratio of carbon dioxide to hydrogen sulfide is no greater than about 6.