US 2026/0265053 A1Published application

Process for producing hydrogen

AssigneeJohnson Matthey Davy Technologies Limited

InventorsMileta BABOVIC, Michiel NIJEMEISLAND, Iain James Olson ROBERTS, Majid SADEQZADEH BOROUJENI

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Abstract

The invention relates to process for the production of hydrogen comprising the steps of: hydrodesulphurisation, reforming in an autothermal reformer, water-gas shift, carbon dioxide separation, and hydrogen purification. The hydrogen purification step produces a hydrocarbon-containing off-gas stream which is split: a portion is used as a fuel gas stream which is fed to one or more fired heaters used to heat one or more process streams within the process, the remainder is compressed and split into a hydrodesulphurisation recycle stream which is used in the hydrodesulphurisation unit, and a process recycle stream which is returned to the process. The invention also relates to a chemical plant configured to carry out the process.

Claims16

Dependent claims

A process for the production of hydrogen comprising the steps of:

(i) passing a hydrogen stream and a feed stream comprising hydrocarbons to a hydrodesulphurisation unit and carrying out hydrodesulphurisation to produce a purified hydrocarbon stream;
(ii) adding steam to the purified hydrocarbon stream to produce a gaseous mixture comprising hydrocarbons and steam;
(iii) subjecting the gaseous mixture comprising hydrocarbons and steam to steam reforming in a reforming section comprising an autothermal reformer to generate a reformed gas mixture;
(iv) increasing the hydrogen content of the reformed gas mixture by subjecting it to one or more water-gas shift stages in a water-gas shift section to provide a hydrogen-enriched reformed gas;
(v) cooling the hydrogen-enriched reformed gas and separating condensed water therefrom to provide a de-watered hydrogen-enriched reformed gas;
(vi) passing the de-watered hydrogen-enriched reformed gas to a carbon dioxide separation unit to provide a carbon dioxide gas stream and a crude hydrogen gas stream;
(vii) passing the crude hydrogen gas stream from the carbon dioxide removal unit to a purification unit to provide a purified hydrogen gas stream and a hydrocarbon-containing off-gas stream;
(viii) splitting the off-gas stream into a fuel gas stream and a recycle stream, wherein the fuel gas stream is fed to one or more fired heaters used to heat one or more process streams within the process;
(ix) compressing the recycle stream;
(x) splitting the compressed recycle stream into a hydrodesulphurisation recycle stream and a process recycle stream;
(xi) feeding the hydrodesulphurisation recycle stream to the hydrodesulphurisation unit;
(xii) returning the process recycle stream to one or more locations selected from:
(xii-a) downstream from the hydrodesulphurisation unit and upstream from the autothermal reformer;
(xii-b) downstream from the autothermal reformer and upstream from the water-gas shift section;
(xii-c) downstream from the water-gas shift section and upstream from the carbon dioxide separation unit;
or
(xii-d) downstream from the carbon dioxide separation unit and upstream from the purification unit.

14 more elements

A chemical plant comprising:

(i) a hydrodesulphurisation unit arranged to accept a hydrogen stream and a feed stream comprising hydrocarbons and to carry out hydrodesulphurisation to produce a purified hydrocarbon stream;
(ii) means for adding steam to the purified hydrocarbon stream to produce a gaseous mixture comprising hydrocarbons and steam;
(iii) a reforming section comprising an autothermal reformer, arranged to accept said gaseous mixture comprising hydrocarbons and steam to produce a reformed gas mixture;
(iv) a water-gas shift section comprising one or more water-gas shift stages arranged to accept said reformed gas mixture to produce a hydrogen-enriched reformed gas;
(v) means for cooling the hydrogen-enriched reformed gas and separating condensed water therefrom to produce a de-watered hydrogen-enriched reformed gas;
(vi) a carbon dioxide separation unit arranged to accept said de-watered hydrogen-enriched reformed gas to produce a carbon dioxide gas stream and a crude hydrogen gas stream;
(vii) a purification unit arranged to accept said crude hydrogen gas stream and to produce a purified hydrogen gas stream- and a hydrocarbon-containing off-gas stream;
(viii) means for splitting the off-gas stream into a fuel gas stream and a recycle stream, wherein the fuel gas stream is fed to one or more fired heaters used to heat one or more process streams within the process;
(ix) means for compressing the recycle stream;
(x) means for splitting the compressed recycle stream into a hydrodesulphurisation recycle stream and a process recycle stream;
(xi) means for feeding the hydrodesulphurisation recycle stream to the hydrodesulphurisation unit;
(xii) means for returning the process recycle stream to one or more locations selected from:
(xii-a) downstream from the hydrodesulphurisation unit and upstream from the autothermal reformer;
(xii-b) downstream from the autothermal reformer and upstream from the water-gas shift section;
(xii-c) downstream from the water-gas shift section and upstream from the carbon dioxide separation unit;
or
(xii-d) downstream from the carbon dioxide separation unit and upstream from the purification unit.

14 more elements

Dependencies are inferred from the claim text.