Process for the production of hydrogen

Patent metadata

Field	Value
Publication number	US-9458013-B1
Application number	US-201514722331-A
Country	US
Kind code	B1
Filing date	May 27, 2015
Priority date	May 27, 2015
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

Process for the production of a H 2 -containing product in a hydrogen production facility comprising a catalytic steam-hydrocarbon reformer and a pressure swing adsorption unit. The process comprises a catalytic steam-hydrocarbon reformer shutdown mode, a pressure swing adsorption unit shutdown mode, a pressure swing adsorption unit maintenance state, a pressure swing adsorption unit startup mode, and a catalytic steam-hydrocarbon reformer startup mode. The pressure swing adsorption unit startup mode comprises purging the adsorption beds with N 2 , then purging the adsorption beds with H 2 , and then adjusting the pressure of the H 2 in the adsorption beds to within defined target pressure ranges.

First claim

We claim:

1. A process for the production of a H 2 -containing product in a hydrogen production facility comprising a catalytic steam-hydrocarbon reformer and a pressure swing adsorption unit, the catalytic steam-hydrocarbon reformer comprising a plurality of catalyst-containing reformer tubes in a reformer furnace and the pressure swing adsorption unit comprising a plurality of adsorption beds, the process comprising:
in a catalytic steam-hydrocarbon reformer production state, introducing a reformer feed gas mixture into the plurality of catalyst-containing reformer tubes, reacting the reformer feed gas mixture in a reforming reaction under reaction conditions effective to form a reformate comprising H 2 , CO, CH 4 , and H 2 O, and withdrawing the reformate from the plurality of catalyst-containing reformer tubes, and combusting a fuel with an oxidant gas in the reformer furnace external to the plurality of catalyst-containing tubes wherein the fuel comprises at least a portion of a by-product gas from the pressure swing adsorption unit;
in a pressure swing adsorption unit production state, separating a pressure swing adsorption unit feed gas formed from at least a portion of the reformate withdrawn from the plurality of catalyst-containing reformer tubes of the catalytic steam-hydrocarbon reformer undergoing the catalytic steam-hydrocarbon reformer production state in the pressure swing adsorption unit to produce the H 2 -containing product and the by-product gas, wherein each of the plurality of adsorption beds are subjected to a repetitive cycle of steps, the repetitive cycle of steps comprising a production step, a depressurizing equalization step, a blowdown step, a pressurizing equalization step, and a pressurization step;
in a catalytic steam-hydrocarbon reformer shutdown mode, discontinuing introduction of the reformer feed gas mixture into the plurality of catalyst-containing tubes and discontinuing combustion of the fuel with the oxidant gas, wherein the catalytic steam-hydrocarbon reformer shutdown mode is subsequent to the catalytic steam-hydrocarbon reformer production state;
in a pressure swing adsorption unit shutdown mode, discontinuing introduction of the pressure swing adsorption unit feed gas into the plurality of adsorption beds due to the catalytic steam-hydrocarbon reformer entering the catalytic steam-hydrocarbon reformer shutdown mode, and subsequently purging the plurality of adsorption beds with N 2 to provide a N 2 concentration in each of the plurality of adsorption beds greater than 96 volume % N 2 , wherein the pressure swing adsorption unit shutdown mode occurs after the pressure swing adsorption unit production state;
in a pressure swing adsorption unit maintenance state, halting the repetitive cycle of steps and introducing air into the plurality of adsorption beds wherein at least a portion of the N 2 in the plurality of adsorption beds that was introduced during the pressure swing adsorption shutdown mode escapes the plurality of adsorption beds;
in a pressure swing adsorption unit startup mode, purging the plurality of adsorption beds with N 2 to decrease the concentration of O 2 in each of the plurality of adsorption beds to less than 1.3 volume % O 2 , subsequently purging the plurality of adsorption beds with H 2 to provide a H 2 concentration in each of the plurality of adsorption beds greater than 85 volume % H 2 , and adjusting a pressure of the H 2 inside each of the plurality of adsorption beds to within a respective defined target pressure range for each of the plurality of adsorption beds, the respective defined target pressure range defined by the step each adsorption bed will undergo first upon restarting the repetitive cycle of steps, wherein the pressure swing adsorption unit startup mode is subsequent to the pressure swing adsorption unit maintenance state; and
in a catalytic steam-hydrocarbon reformer startup mode, introducing a startup-mode reformer feed gas mixture into the plurality of catalyst-containing reformer tubes, reacting the startup-mode reformer feed gas mixture under reaction conditions effective to form a startup-quality reformate comprising H 2 , CO, CH 4 , and H 2 O, and withdrawing the startup-quality reformate from the plurality of catalyst-containing reformer tubes, and combusting a startup-mode fuel with a startup-mode oxidant gas in the reformer furnace external to the plurality of catalyst-containing tubes;
wherein at least a portion of the pressure swing adsorption startup mode is concurrent with at least a portion of the catalytic steam-hydrocarbon reformer startup mode.

2. The process according to claim 1 wherein during the pressure swing adsorption unit startup mode, the plurality of adsorption beds are purged with H 2 independent of any of the plurality of adsorption beds undergoing any step of the repetitive cycle of steps and/or the pressure of the H 2 inside each of the plurality of adsorption beds is adjusted to within the respective defined target pressure range for each of the plurality of adsorption beds independent of any of the plurality of adsorption beds undergoing any step of the repetitive cycle of steps.

3. The process of claim 1 wherein during the pressure swing adsorption unit startup mode, the repetitive cycle of steps is still halted.

4. The process of claim 3 , wherein during the pressure swing adsorption unit startup mode, the plurality of adsorption beds are purged with H 2 and/or the pressure of the H 2 inside each of the plurality of adsorption beds is adjusted prior to undergoing any step of the repetitive cycle of steps.

5. The process of claim 1 further comprising restarting the repetitive cycle of steps subsequent to completing the pressure swing adsorption unit startup mode.

6. The process of claim 1 wherein during the pressures swing adsorption unit startup mode, the plurality of adsorption beds are purged with N 2 to decrease the concentration of O 2 in each of the plurality of adsorption beds to less than 0.5 volume % O 2 .

7. The process of claim 1 wherein during the pressures swing adsorption unit startup mode, the plurality of adsorption beds are purged with H 2 to provide the H 2 concentration in each of the plurality of adsorption beds where the H 2 concentration is greater than 99 volume % H 2 .

8. The process according to claim 1 wherein during the pressure swing adsorption unit shutdown mode the plurality of adsorption beds are purged with N 2 to provide the N 2 concentration in each of the plurality of adsorption beds where the N 2 concentration is greater than 99.6 volume % N 2 .

9. The process according to claim 1 wherein the pressure swing adsorption startup mode is initiated prior to initiating the catalytic steam-hydrocarbon reformer startup mode.

10. The process of claim 1 wherein no portion of the startup-quality reformate is introduced into any of the plurality of adsorption beds.

11. The process of claim 1 wherein the startup-mode fuel comprises no by-product gas from the pressure swing adsorption unit.

12. The process of claim 1 wherein the H 2 for purging the plurality of adsorption beds during the startup mode is provided from a H 2 pipeline.

13. The process of claim 1 wherein the startup-quality reformate is at least one of vented, flared, or used to form at least a portion of the startup-mode fuel.

14. The process of claim 1 wherein the catalytic steam-hydrocarbon reformer startup mode comprises introducing a N 2 - and steam-containing stream during heat-up of the plurality of catalyst-containing reformer tubes prior to introducing the startup-mode reformer feed gas mixture into the p

Assignees

• Air Prod & Chem

Inventors

• Sicinski Michael Andrew
• Wood Christopher H
• Hoke Jr Bryan Clair

Classifications

• B01D53/047 Primary

  Pressure swing adsorption · CPC title

• B01D2259/40001

  Methods relating to additional, e.g. intermediate, treatment of process gas · CPC title

• C01B3/38 Primary

  using catalysts · CPC title

• C01B2203/0495

  the impurity being water · CPC title

• B01D2257/104

  Oxygen · CPC title