Process for sulfur removal from refinery off gas

Abstract

Organic sulfur compounds contained in refinery off gas streams having either high or low concentrations of olefins are converted to hydrogen sulfides which can be then be removed using conventional amine treating systems. The process uses a catalytic reactor with or without a hydrotreater depending on the olefin concentration of the off gas stream. The catalytic reactor operates in a hydrogenation mode or an oxidation mode to convert a majority of organic sulfur compounds into hydrogen sulfides.

1 - 24 . (canceled) 
     
     
         25 . A process for the removal of H 2 S and organic sulfur compounds from a refinery off gas feed stream containing at least hydrogen and a low concentration of olefins wherein the hydrogen to olefin molar ratio is greater than  0 . 5 , comprising:
 a) removing at least a portion of the H 2 S from the feed stream by passing the feed stream through an amine absorber to produce a H 2 S depleted stream;   b) feeding the H 2 S depleted stream into a catalytic reactor at a temperature between 340° C. and 450° C. to convert a majority of the organic sulfur compounds to H 2 S at the pressure employed;   c) cooling the product gas stream exiting the catalytic reactor; and   d) feeding the cooled product gas stream to an amine sulfur removal system to remove the H 2 S and produce a product gas stream.   
     
     
         26 . The process of  claim 25  wherein the catalytic reactor is a dual mode reactor capable of operating in a hydrogenation mode or an oxidation mode at space velocities of greater than 10,000 hr −1 . 
     
     
         27 . The process of  claim 25  wherein the catalytic reactor employs a catalyst that contains a group VIII metal. 
     
     
         28 . The process of  claim 25  wherein the H 2 S depleted stream is sent into the catalytic reactor with the addition of oxygen. 
     
     
         29 . The process of  claim 25  wherein the H 2 S depleted stream has a pressure of 10 bar or greater and the catalytic reactor operates without the addition of oxygen.