Process for the production of hydrogen

摘要

Process for the production of a H2-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 N2, then purging the adsorption beds with H2, and then adjusting the pressure of the H2 in the adsorption beds to within defined target pressure ranges.

主权项

1. A process for the production of a H2-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 H2, CO, CH4, and H2O, 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production state, separating a pressure swing adsorption unit feed gas formed from at least a portion of the reformate withdrawn from the plurality of catalyst-containing reformer tubes of the catalytic steam-hydrocarbon reformer undergoing the catalytic steam-hydrocarbon reformer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 H2-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 N2 to provide a N2 concentration in each of the plurality of adsorption beds greater than 96 volume % N2, 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 N2 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 N2 to decrease the concentration of O2 in each of the plurality of adsorption beds to less than 1.3 volume % O2, subsequently purging the plurality of adsorption beds with H2 to provide a H2 concentration in each of the plurality of adsorption beds greater than 85 volume % H2, and adjusting a pressure of the H2 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 H2, CO, CH4, and H2O, 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.