US 12,227,416 B2
Pre-combustion CO2 removal in a natural gas fed steam methane reformer (SMR) based hydrogen plant
Ravi Ravikumar, Lancaster, CA (US); and Sunil Singhal, Gurugram (IN)
Assigned to FLUOR TECHNOLOGIES CORPORATION, Irving, TX (US)
Filed by Fluor Technologies Corporation, Irving, TX (US)
Filed on Oct. 13, 2022, as Appl. No. 17/965,608.
Application 17/965,608 is a continuation of application No. 17/176,050, filed on Feb. 15, 2021, granted, now 11,505,462.
Prior Publication US 2023/0042038 A1, Feb. 9, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C01B 3/48 (2006.01); B01D 53/047 (2006.01); B01D 53/14 (2006.01); B01D 53/26 (2006.01); B01D 53/62 (2006.01); B01D 53/78 (2006.01); B01D 53/96 (2006.01); B01J 19/24 (2006.01); C01B 3/50 (2006.01); C01B 3/52 (2006.01); C01B 3/56 (2006.01)
CPC C01B 3/48 (2013.01) [B01D 53/047 (2013.01); B01D 53/1418 (2013.01); B01D 53/1425 (2013.01); B01D 53/1475 (2013.01); B01D 53/265 (2013.01); B01D 53/62 (2013.01); B01D 53/78 (2013.01); B01D 53/96 (2013.01); B01J 19/245 (2013.01); C01B 3/506 (2013.01); C01B 3/52 (2013.01); C01B 3/56 (2013.01); B01D 2252/204 (2013.01); B01D 2257/104 (2013.01); B01D 2257/504 (2013.01); B01D 2257/80 (2013.01); B01J 2219/0004 (2013.01); C01B 2203/0233 (2013.01); C01B 2203/0283 (2013.01); C01B 2203/0415 (2013.01); C01B 2203/042 (2013.01); C01B 2203/047 (2013.01); C01B 2203/0475 (2013.01); C01B 2203/048 (2013.01); C01B 2203/0495 (2013.01); C01B 2203/0883 (2013.01); C01B 2203/1241 (2013.01); C01B 2203/1294 (2013.01); C01B 2203/148 (2013.01)] 13 Claims
OG exemplary drawing
 
1. A process for producing hydrogen from natural gas, the process comprising:
introducing a feed natural gas, a feed steam, and a fuel to a steam methane reformer to produce unshifted synthesis gas (syngas);
introducing the unshifted syngas to a water gas shift unit;
producing a cooled shifted syngas;
removing CO2 from the cooled shifted syngas to produce a CO2 depleted syngas and a CO2 product; and
introducing the CO2 depleted syngas to a pressure swing absorption unit to produce a hydrogen product and an off-gas comprising carbon monoxide, carbon dioxide, unreacted methane, and at least 25 mol % hydrogen based on a total moles of components in the off-gas, wherein the fuel that is introduced to the steam methane reformer comprises the off-gas.
 
7. A hydrogen production system comprising:
a steam methane reformer configured to contact methane and steam with a catalyst to form an unshifted syngas;
a water gas shift unit coupled to the steam methane reformer and configured to receive the unshifted syngas from the steam methane reformer and to produce a shifted syngas;
an absorption unit comprising an absorber and a regenerator coupled to the water gas shift unit and configured to receive the shifted syngas, remove carbon dioxide from the shifted syngas, and produce a CO2 depleted syngas and a CO2 product wherein the regenerator comprises a flash vessel, wherein;
the absorber has a lean physical solvent configured to absorb carbon dioxide from the shifted syngas to produce a CO2 enriched solvent and the CO2 depleted syngas; and
the regenerator comprises the flash vessel comprising one or more flash columns or flash tanks coupled to the absorber, wherein the one or more flash tanks is configured to receive the CO2 enriched solvent from the absorber and to flash carbon dioxide from the CO2 enriched solvent to produce the lean physical solvent and the CO2 product;
a pressure swing absorption unit coupled to the absorption unit, wherein the pressure swing absorption unit is configured to receive the CO2 depleted syngas from the absorption unit and to produce a hydrogen product and an off-gas; and
an off-gas stream coupled to the pressure swing absorption unit and to the steam methane reformer, wherein the off-gas stream is configured to receive the off-gas from the pressure swing absorption unit and to introduce the off-gas to the steam methane reformer, wherein the off-gas in the off-gas stream comprises carbon monoxide, carbon dioxide, unreacted methane, and at least 25 mol % hydrogen based on a total moles of components in the off-gas stream.
 
11. A process for producing hydrogen from natural gas, the process comprising:
producing a flue gas from a steam methane reformer;
cooling the flue gas to produce a cooled flue gas;
splitting the cooled flue gas into a first portion and a second portion;
compressing the first portion to produce a compressed first portion;
removing CO2 from the compressed first portion by an amine-based absorption to produce a residual CO2 and a CO2 depleted flue gas; and
removing O2 from the CO2 depleted flue gas by a pressure swing absorption to produce a N2 product.