Hydrogen production system and method for producing hydrogen using the same
AssigneesHyundai Motor Company, Kia Corporation
InventorsDong Seok Ko, Jung Joo Park
Life of this patent
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Abstract
A hydrogen production system and a method for producing hydrogen that may minimize carbon dioxide emissions of an overall process by combining a steam-methane reformation process with a combined steam-carbon reformation process, and using a feed controller to appropriately control flow rates of steam and hydrocarbon gas feed input to the combined steam-carbon reformation process based on a composition and a flow rate of off-gas input from the steam-methane reformation process to the combined steam-carbon reformation process.
Claims13
A hydrogen production system comprising:
- a steam-methane reformer configured to receive steam and hydrocarbon gas;
- a first conversion reactor in fluid communication with the steam-methane reformer;
- a first adsorption separation process unit in fluid communication with the first conversion reactor and configured to separate high purity hydrogen gas;
- a combined steam-carbon reformer configured to receive steam and hydrocarbon gas;
- a second conversion reactor in fluid communication with the combined steam-carbon reformer;
- and
- a second adsorption separation process unit in fluid communication with the second conversion reactor and configured to separate high purity hydrogen gas;
- wherein the first adsorption separation process unit is connected to and in fluid communication with the combined steam-carbon reformer;
- and
- wherein the hydrogen production system includes a feed controller configured to control flow rates of steam and hydrocarbon gas introduced into the combined steam-carbon reformer based on a composition and a flow rate of off-gas flowing into the combined steam-carbon reformer from the first adsorption separation process unit.
A method for producing hydrogen, the method comprising:
- allowing steam and methane gas to react with each other to obtain first stream containing carbon monoxide gas, steam, and hydrogen gas;
- performing conversion reaction on the first stream to obtain second stream containing carbon dioxide gas and hydrogen gas;
- obtaining hydrogen gas by separating the hydrogen gas from the second stream and adding and reacting additional steam and methane gas to remaining off-gas to obtain third stream containing carbon monoxide gas, steam, and hydrogen gas;
- performing the conversion reaction on the third stream to obtain fourth stream containing carbon dioxide gas and hydrogen gas;
- and
- obtaining hydrogen gas by separating the hydrogen gas from the fourth stream;
- wherein molar flow rates of additional steam and hydrocarbon gas introduced into off-gas in the separating of the hydrogen gas from the second stream are determined via Equation 1:
- [
- Feed
-
- H
- 2
-
- O
- ]
- =
- [
- CO
- 2
- ]
- ×
- [
- Eq
-
- 2
- ]
- -
- [
- H
- 2
-
- O
- ]
- ;
- and
- Equation 2:
- [
- Feed
-
- CH
- 4
- ]
- =
- (
- [
- CO
- 2
- ]
- ×
- (
- 1
- +
- [
- Eq
-
- 2
- ]
- )
- )
-
- /
- [
- Eq
-
- 1
- ]
- -
- [
- CH
- 4
- ]
- ;
- wherein [CO2] refers to a molar flow rate (kmol/hr) of carbon dioxide gas in off-gas,
- [H2O] refers to a molar flow rate (kmol/hr) of steam in off-gas,
- [CH4] refers to a molar flow rate (kmol/hr) of methane gas in off-gas,
- [Eq1] is a constant between 1.5 and 2.0, and
- [Eq2] is a constant equal to or greater than 1.
Dependencies are inferred from the claim text.