Patent ID: 8409427
Filing Date: 2013-04-02
Classification: C01B,C10G

Abstract:
1. A method of producing a treated hydrocarbon containing stream for use as a feed to a hydrogen plant having a steam methane reformer, said method comprising: contacting an untreated hydrocarbon containing feed stream of variable composition comprising hydrocarbons that contain two or more carbon atoms including olefins, organic sulfur species and hydrogen with a sulfur tolerant catalyst contained within a reaction stage and capable of promoting both hydrogenation and oxidation reactions, wherein the untreated hydrocarbon containing feed stream is a refinery off-gas that is compressed to a pressure greater than a preheated natural gas stream produced in the hydrogen plant; converting part of the olefins into saturated hydrocarbons and part of the sulfur species to hydrogen sulfide within the reaction stage, thereby to produce a first intermediate stream, through hydrogenation reactions promoted by the catalyst or by introducing sufficient oxygen and steam into the reaction stage such that oxidation reactions are promoted by the catalyst resulting in the saturated hydrocarbons, methane, additional hydrogen and carbon monoxide being produced from the hydrocarbons contained in the untreated hydrocarbon containing feed stream, combining the first intermediate stream with the preheated natural gas stream to produce a combined stream containing between about 0.5 mol percent and 6 mol percent olefins on a dry basis and less than about 25 ppm by volume of total sulfur on a dry basis; the first intermediate stream is passed through a boiler to generate saturated steam for the hydrogen plant and is thereby cooled to a temperature of between about 260° C. and about 480° C. prior to being combined with the preheated natural gas stream; prior to the hydrocarbon containing feed stream being introduced into the reaction stage, the untreated hydrocarbon containing feed stream, after compression, is: preheated to a temperature of about 230° C. through indirect heat exchange with steam generated in the hydrogen plant; preheated in a feed preheater through indirect heat exchange with a synthesis gas stream produced in the hydrogen plant to a temperature of between about 260° C. and about 400° C.; and thereafter, subjected to a pretreatment stage configured to remove incoming hydrogen sulfide from the untreated hydrocarbon containing feed stream; introducing at least the first intermediate treated hydrocarbon containing feed stream into a hydrotreater having another catalyst that is capable of solely promoting hydrogenation reactions and producing a second intermediate stream containing no greater than about 0.5 mol percent of the olefins on a dry basis and no greater than about 0.1 ppm by volume organic sulfur on a dry basis, and having a greater amount of the hydrogen sulfide than that of the first intermediate stream and lower amounts of the olefins and the organic sulfur species than that of the first intermediate stream by subjecting olefin and organic sulfur species slip in the first intermediate stream to hydrogenation reactions; and adsorbing the hydrogen sulfide in the second intermediate stream, thereby to produce the treated hydrocarbon containing stream.