SYSTEMS AND METHODS FOR WATER GAS SHIFT WITH REDUCED STEAM CONSUMPTION

摘要

A water gas shift reaction is carried out on a feed gas comprising carbon monoxide to produce carbon dioxide and hydrogen gas. The feed gas is split into multiple input streams flowed into respective reactors coupled in series. Steam is supplied to the input stream fed to the first reactor. The shift reaction is carried out in each reactor, with an overall reduced consumption of steam relative to the amount of gas shifted. The water gas shift reaction may be performed in conjunction with removing acid gas compounds from a process gas such as, for example, syngas or natural gas, by flowing a feed gas into a desulfurization unit to remove a substantial fraction of sulfur compounds from the feed gas and flowing the resulting desulfurized gas into a CO2 removal unit to remove a substantial fraction of CO2 from the desulfurized gas.

主权项

1. A method for producing a water-gas shifted gas comprising CO2 and H2, the method comprising:
splitting a flow of feed gas comprising carbon monoxide (CO) into a plurality of feed gas streams comprising at least a first feed gas stream, a second feed gas stream, and a third feed gas stream; combining the first feed gas stream with a steam stream to produce a first input gas stream; flowing the first input gas stream into a first shift reactor containing a first shift catalyst; reacting the CO with the steam in the presence of the first shift catalyst to produce a first product gas stream comprising carbon dioxide (CO2) and hydrogen (H2); combining the first product gas stream with the second feed gas stream to produce a second input gas stream heated by the first product gas stream; before combining the first product gas stream with the second feed gas stream, adding water as a spray to the first product gas stream to vaporize the water into steam, wherein the first product gas stream is cooled before being combined with the second feed gas stream; flowing the second input gas stream into a second shift reactor containing a second shift catalyst; reacting the CO of the second input gas stream with the steam in the presence of the second shift catalyst to produce a second product gas stream comprising CO2 and H2; combining the second product gas stream with the third feed gas stream to produce a third input gas stream heated by the second product gas stream; before combining the second product gas stream with the third feed gas stream, adding water as a spray to the second product gas stream to vaporize the water into steam, wherein the second product gas stream is cooled before being combined with the third feed gas stream; flowing the third input gas stream into a third shift reactor containing a third shift catalyst; and reacting the CO of the third input gas stream with the steam in the presence of the third shift catalyst to produce a third product gas stream comprising CO2 and H2.