초록 ▼

A process for preparing a hydrogen and carbon monoxide containing synthesis gas for hydrocarbon synthesis includes autothermally reforming a natural gas (CH4) feed with oxygen, steam and recycled carbon dioxide and, optionally, recycled hydrocarbon by-products from the hydrocarbon synthesis step. Th

A process for preparing a hydrogen and carbon monoxide containing synthesis gas for hydrocarbon synthesis includes autothermally reforming a natural gas (CH4) feed with oxygen, steam and recycled carbon dioxide and, optionally, recycled hydrocarbon by-products from the hydrocarbon synthesis step. The reforming is carried out in an autothermal reformer comprising a first monolithic catalyst zone utilizing a palladium and platinum containing catalyst followed by a second platinum group metal steam reforming zone. The product of the autothermal reformer comprises hydrogen, carbon oxides and water. Carbon dioxide and water are removed from the reformer effluent and recycled to the reformer. The resulting synthesis gas comprises hydrogen and carbon monoxide in a selected ratio for passage to, e.g., a Fischer-Tropsch synthesis process. Light and heavy hydrocarbon by-products of the Fischer-Tropsch process may be recycled to the autothermal reformer.

대표청구항 ▼

A process for preparing from a normally gaseous hydrocarbon feed a synthesis gas comprising hydrogen and carbon oxides and suitable for the synthesis of normally liquid hydrocarbons therefrom, the process comprising the steps of: (a) preheating to a preheat temperature an inlet stream comprising a n

A process for preparing from a normally gaseous hydrocarbon feed a synthesis gas comprising hydrogen and carbon oxides and suitable for the synthesis of normally liquid hydrocarbons therefrom, the process comprising the steps of: (a) preheating to a preheat temperature an inlet stream comprising a normally gaseous hydrocarbon feed, H2O, oxygen and recycled carbon dioxide obtained as defined below, the preheat temperature being sufficiently high to initiate catalytic oxidation of said feed as defined below: (b) introducing the preheated inlet stream into a first catalyst zone comprising a monolithic body having a plurality of gas flow passages extending therethrough and having a catalytically effective amount of palladium and platinum catalytic components dispersed therein, the amounts of feed, H2O and oxygen introduced into said first catalyst zone being controlled to maintain in said inlet stream an H2O to C ratio of from about 0.5 to 5 and an O2 to C ratio of from about 0.4 to 0.65; (c) contacting the preheated inlet stream within said first catalyst zone with said palladium and platinum catalytic components to initiate and sustain therein catalytic oxidation of said feed to produce hydrogen and carbon oxides therefrom, the temperature of at least a portion of said monolithic body being at least about 250°F. (139°C.) greater than the ignition temperature of said inlet stream, and oxidizing in said first catalyst zone a quantity, less than all, of said feed, which quantity is sufficient to heat such first zone effluent to an elevated temperature high enough to catalytically steam reform, within a second catalyst zone defined below, the hydrocarbons in such first zone effluent without supplying external heat thereto; (d) passing the first zone effluent, while still at the elevated temperature, from said first catalyst zone to a second catalyst zone containing a platinum group metal steam reforming catalyst therein, and contacting the first zone effluent in said second catalyst zone with said reforming catalyst to react hydrocarbons therein with H2O to produce hydrogen and carbon oxides therefrom and thereby provide a gas mixture including hydrogen, carbon monoxide and carbon dioxide; (e) passing the effluent of said second catalyst zone to a carbon dioxide removal zone and separating carbon dioxide form the second zone effluent; (f) recycling the carbon dioxide separated in step (e) to said inlet stream in an amount sufficient so that said inlet stream comprises from about 5 to 20 mole percent carbon dioxide; and (g) withdrawing the carbon dioxide-depleted second-zone effluent obtained in step (e) as said synthesis gas.