Patent ES-338043-A1 (ES)
Title: Process for producing hydrogen by reaction of a hydrocarbon and steam employing a rhenium-containing catalyst
IPC: B01J23/16
Filed: 1967-03-15
Abstract: A process for the preparation of hydrogen or hydrogen-containing gas mixtures comprises steam conversion of hydrocarbons and/or organic sulphur compounds in the presence of rhenium and/or rhenium-containing compositions as catalyst. Rhenium may be present as the metal, as an oxide, or preferably as its sulphide, may be promoted by one of the metals Ag, Ni, Co, Cu, Au or a compound thereof, but preferably by Ir, and may be supported on alumina containing <5% by weight silica the conventional impregnation method may be used to prepare the catalyst which, before or after calcination, is sulphided if desired. The catalyst may contain 1-25% by weight rhenium. The hydrocarbon feed is a pure compound, a hydrocarbon mixture or a hydrocarbon oil fraction boiling below 200 DEG C., particularly a C5-C7 (aliphatic, aromatic or naphthenic) fraction, a straight run "tops" fraction, a light naphtha fraction or the product of catalytic reforming or steam cracking of hydrocarbon oil fractions, preferably, if the sulphide of rhenium is used as the catalyst, containing 0.01-10% by weight sulphur. Alternatively an organic sulphur compound, e.g. benzothiophene may constitute the feed. The conversion is carried out with 1-40 moles steam per mole feed, optionally in the presence of oxygen, at a pressure below 60 atm. absolute and with a fixed or, preferably, fluidized bed of catalyst, and at temperatures ranging from between 400-600 DEG C., when hydrogen and lower molecular weight hydrocarbons are obtained, to above 700 DEG C., even above 800 DEG C. when complete conversion of the carbon content to carbon monoxide is achieved. Recoverable products thus include H2 + CO gas mixtures and lighter hydrocarbons, particularly propane and butane, from which pure hydrogen may be separated, for example by removal of CO from the binary mixture CO + H2 by conversion to methanol, or by shift conversion with added steam at 350 -500 DEG C. and removal of the CO2 formed. Conversion of benzothiphene to toluene, with the production of H2, H2S and carbonic acid, of toluene to benzene, of n-pentane to hydrogen and C1-C4 molecules and of tops fractions to hydrogen, propane and butane are referred to or exemplified.ALSO:A process for the preparation of hydrogen or hydrogen-containing gas mixtures comprises steam conversion of hydrocarbons and/or organic sulphur compounds in the presence of rhenium and/or rhenium-containing compositions as catalyst. Rhenium may be present as the metal, an oxide or preferably its sulphide, may be promoted by Ag, Ni, Co, Au, Cu or a compound thereof, but preferably Ir, and may be supported on alumina containing <5% by wt. silica the catalyst may contain 1-25% by wt. rhenium. If rhenium sulphide is employed the feed preferably contains 0.01-10% by wt. sulphur alternatively the feed may be sulphur-containing such as benzothiophene. Conversion is effected with 1-40 moles steam per mole feed, optionally oxygen, less than 60 atm. pressure, a fixed or preferably fluidized catalyst bed, and temperatures of 400-600 DEG C. (partial conversion to hydrogen and lower hydrocarbons) or above 700 DEG C. (complete conversion to carbon monoxide). Recoverable products include H2 + Co mixtures from which pure hydrogen may be separated by conversion of Co to methanol, or shift conversion at 350-500 DEG C. and removal of CO2.ALSO:A catalyst suitable for steam conversion of hydrocarbons and/or organic sulphur compounds comprises rhenium and/or a rhenium-containing composition wherein the rhenium may be present as metal, oxide or preferably sulphide, may be promoted by Ag, Ni, Ci, Cu, Au, a compound thereof or preferably Ir, and may be supported on alumina containing not more than 5% by weight silica the catalyst may contain 1-25% rhenium. It may be prepared conventionally, by impregnation of the carrier with a soluble rhenium salt (with or without metal salts of promoters), calcination, reduction, and sulphiding with hydrogen sulphide or a mercaptan alternatively the oxide may be sulphided directly.