Integrated hydrogen production process

摘要

The present invention provides an integrated process for producing a fermentation product from fossil carbon and hydrogen present in a purge gas stream resulting from a hydrogen production process. According to the invention, a purge gas stream obtained from a hydrogen production process is fermented with microorganisms in one or more bioreactors to produce the fermentation product. A fermentation exhaust gas stream from the one or more bioreactors comprising hydrogen, carbon monoxide and/or methane is then obtained and heat is generated therefrom to provide energy for a reforming unit that forms part of the hydrogen production process.

主权项

1. An integrated hydrogen production process comprising:
(i) providing a purge gas stream obtained from a process comprising the steps of:
(a) converting fossil methane to carbon monoxide and hydrogen by reforming in a reforming unit;(b) converting at least a portion of the carbon monoxide by a water-gas shift reaction to carbon dioxide, thereby producing a stream comprising carbon dioxide and hydrogen; and(c) separating at least a portion of the hydrogen from the stream of step (b) from non-hydrogen components to produce a stream enriched in hydrogen and a purge gas stream comprising hydrogen and at least one of carbon dioxide, methane and carbon monoxide; (ii) fermenting the purge gas stream, or a portion thereof, with microorganisms in one or more bioreactors to produce a fermentation product; (iii) providing a fermentation exhaust gas stream from the one or more bioreactors, said exhaust gas stream comprising one or more combustible gases; (iv) generating heat from the exhaust gas stream and using the heat to provide energy for the reforming unit; (v) generating additional heat from a fuel gas stream and using the heat produced from the fuel gas stream to provide energy for the reforming unit, wherein the rate of fuel gas used to provide such additional heat is at least the rate of production of product energy associated with the fermentation product produced in step (ii), and wherein the rate of production is the heat of combustion of the fermentation product produced times the quantity of fermentation product produced measured in BTU/hr; and (vi) wherein the fermentation product is recovered.