Energetically enhanced reforming process
Methods and systems for producing hydrogen from methane or other fuels that has lower input heat requirements than conventional steam reformation schemes are provided. The system has a reactor with a controlled feed of fuel, water/steam, CO and recycle gases. The methods generally use significantly high amounts of steam (water) and carbon monoxide (CO) in the feed that substantially enhances the reaction rate of the water-gas shift reaction, which transforms CO and H 2 O to CO 2 and H 2 . Since this reaction is exothermic, its enhancement alters the endothermic nature of the overall reforming process to the point where the overall reforming process is no longer endothermic. The CO requirements may be met in part with the reverse water-gas shift reaction from CO 2 produced by the reactor. The lower heat requirements may be satisfied with renewable sources such as solar or from hydrogen produced by the system.
1. An energy efficient method for the production of hydrogen gas, the method comprising:
(a) flowing a H 2 O/CO/CH 4 feed with a feed ratio of H 2 O/CO/CH 4 of 18/15/1 into a reactor;
(b) reforming the feed gases to produce a stream of H 2 , CO 2 and residual H 2 O, CO and CH 4 feed gases;
(c) separating H 2 O from the stream and recycling separated water to the reactor;
(d) separating CO 2 from the stream;
(e) purifying H 2 from the stream; and
(f) recycling remaining gases from the H 2 separation to the reactor.
2. The method of claim 1 , further comprising:
converting CO 2 from the stream to CO; and
recycling the CO to the reactor feed.
3. The method of claim 1 , further comprising:
combusting hydrogen gas from an output stream of purified hydrogen gas to provide system heat requirements.
4. The method of claim 1 , wherein the reactor operating temperature and pressure are 1140K and 5 bar respectively.
5. The method of claim 1 , wherein the heat requirements of the system are a (770K) utility and a (420 K) utility.
6. The method of claim 1 , wherein the carbon monoxide feed is produced by partial oxidation of a hydrocarbon fuel selected from the group of fuels consisting of methane, ethane, ethanol, methanol and gasoline.
7. The method of claim 6 , further comprising:
converting CO 2 from the stream to CO; and
cycling the converted CO with the CO produced by partial oxidation to the reactor feed.