INTEGRATION OF AMMONIA FUEL FOR SMR FOR HYDROGEN PRODUCTION

20240182300

18/076132

December 06, 2022

A method of producing hydrogen from a hydrocarbon feedstock is provided. Wherein, at least a portion of a fuel stream comprises a superheated ammonia stream. And, at least: a first portion of a hydrogen-rich stream is combined with a shifted syngas stream prior to introduction into a pressure swing adsorber, a second portion of the hydrogen-rich stream is combined with the fuel stream prior to introduction into a steam methane reformer, and/or a third portion of the hydrogen-rich stream is combined with a hydrocarbon containing feedstock stream and a steam stream prior to introduction into a feed pre-heater. Heat integration between the ammonia vaporization and superheating steps is employed to cool process streams to minimize and even eliminate a dedicated cryogenic refrigeration system.

1. A method of producing hydrogen from a hydrocarbon feedstock, comprising: introducing a hydrocarbon containing feedstock stream and a steam stream into a feed pre-heater, thereby producing a heated process stream, introducing the heated process stream to the tube side and a fuel stream into the fired side of a steam methane reformer thereby producing a raw syngas stream, introducing the raw syngas stream into a water-gas shift reactor, thereby producing a shifted syngas stream, introducing the shifted syngas stream into a pressure swing adsorption unit, thereby producing a hydrogen product stream and a PSA tail-gas stream, introducing the PSA tail-gas stream into a hydrogen recovery unit, thereby producing a hydrogen-rich stream and a hydrogen-lean stream, wherein, at least a portion of the fuel stream comprises a superheated ammonia stream, wherein, at least: a first portion of the hydrogen-rich stream is combined with the shifted syngas stream prior to introduction into the pressure swing adsorber, a second portion of the hydrogen-rich stream is combined with the fuel stream prior to introduction into the steam methane reformer, and/or a third portion of the hydrogen-rich stream is combined with the hydrocarbon containing feedstock stream and the steam stream prior to introduction into the feed pre-heater.

2. The method of claim 1, wherein a liquid ammonia stream is vaporized and superheated thereby producing the superheated ammonia stream.

3. The method of claim 1, wherein the hydrogen-lean stream is cryogenically separated into a carbon dioxide product stream

4. The method of claim 1, wherein a liquid ammonia stream is vaporized by indirect heat exchange thereby requiring a first heating duty thereby producing a vaporized ammonia stream, which is then superheated thereby producing the superheated ammonia stream, wherein the hydrogen-lean stream and PSA tail-gas stream are combined and cryogenically cooled by indirect heat exchange thereby requiring a first cooling duty, wherein at least a portion of the first cooling duty is provided by the first heating duty.

5. The method of claim 1, wherein a liquid ammonia stream is vaporized, thereby producing a vaporized ammonia stream, which is then superheated by indirect heat exchange thereby requiring a second heating duty, thereby producing the superheated ammonia stream, wherein the PSA tail-gas stream is compressed and then cooled by indirect heat exchange thereby requiring a second cooling duty, wherein at least a portion of the second cooling duty is provided by the second heating duty.

6. The method of claim 1, wherein substantially all of the fuel stream comprises the superheated ammonia stream and the second portion of the hydrogen-rich stream.

7. The method of claim 1, wherein there is no independent, dedicated system to provide additional refrigeration.

8. The method of claim 1, further comprising introducing an oxygen-enriched oxidant stream into the steam methane reformer.

9. The method of claim 1, further comprising introducing the heated process stream into a pre-reforming unit prior to being introduced into the steam methane reformer.

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