Patent ID: 8580153
Filing Date: 2013-11-12
Classification: C01B,Y02P

Abstract:
1. A method of reducing the carbon dioxide production and shifting balance from a reformer furnace flue gas to a high pressure syngas exit water gas shift reaction unit, the method comprising the steps of: a) providing a first gas mixture; b) heating said first stream mixture to a first temperature, then introducing said heated first gas mixture into a pre-reforming chamber to produce a pre-reformed mixture; c) further heating said pre-reformed mixture in a primary reformer, thereby generating a second gas mixture comprising hydrogen, carbon monoxide, carbon dioxide, and a flue gas, wherein said primary reformer comprises a reformer furnace and tubes filled with catalyst, wherein the second mixture and/or the flue a provides said heating for step b); d) introducing said second gas mixture into at least one isothermal shift reactor, or a combination of high followed by a low temperature shift reactor, or a medium temperature shift reactor, thereby generating a third gas mixture; e) introducing said third gas mixture into an amine wash, thereby producing an carbon dioxide enriched stream and a sweet syngas stream; f) introducing said sweet syngas stream into a PSA unit, wherein said sweet syngas stream is separated into a hydrogen enriched stream and a PSA tail gas stream; and g) introducing said PSA tail gas stream as fuel into the reformer furnace along with natural gas, a portion of the feed hydrocarbon stream, a portion of the hydrogen enriched stream, or any other external make-up fuel for the reformer furnace, wherein step b) is repeated in a second pre-reforming chamber and a third pre-reforming chamber, for a total of three pre-reforming steps, such that the resulting temperature of the pre-reformed mixture is higher after each repetition, wherein each pre-reforming chamber comprises a bed of pre-reformer catalyst wherein an outlet gas from each pre-reforming chamber is heated up in a coil in exchange with flue gas or the second gas mixture before going to the next pre-reforming chamber or before entering the tubes of the primary reformer, wherein a portion of the PSA tail gas stream is compressed and recycled to the PSA unit.