Steam methane reforming with process carbon dioxide capture and ammonia firing

A method for producing hydrogen in a steam methane reformer with reduced carbon emissions, the method comprising a first mode of operation and a second mode of operation, wherein during both modes of operation, the method comprises the steps of:

• a) heating a feed stream comprising methane in a first heat exchanger to produce a heated feed stream, wherein the heated feed stream is at a temperature above 500° C.;
• b) introducing the heated feed stream into a reaction zone under conditions effective for catalytically cracking the heated feed stream to produce reformed stream, wherein the reformed stream comprises hydrogen, carbon monoxide, and unreacted methane;
• c) introducing the reformed stream in the presence of steam to a shift conversion unit that is configured to produce a shifted gas stream comprising hydrogen and carbon dioxide;
• d) purifying the shifted gas stream to produce a hydrogen product stream and a tail gas;
• and
• e) removing carbon dioxide from a stream selected from the group consisting of a first stream, a second stream, and combinations thereof, wherein the first stream is the shifted gas stream, wherein the second stream is the tail gas,
• wherein the conditions effective for catalytically cracking the heated feed stream comprise providing heat to the reaction zone via combustion of a fuel and a hydrogen fuel stream in the presence of an oxidizer, wherein the hydrogen fuel stream comprises at least a first portion of the tail gas,
• wherein a flue gas is produced by the combustion of the fuel and the hydrogen fuel stream,
• wherein during the first mode of operation, the fuel comprises a hydrocarbon,
• wherein during the second mode of operation, the fuel comprises ammonia,
• wherein the flue gas produced by the second mode of operation comprises less carbon dioxide than the flue gas produced by the first mode of operation.

A method for producing hydrogen in a steam methane reformer comprising the steps of:

• a) heating a feed stream comprising methane in a first heat exchanger to produce a heated feed stream, wherein the heated feed stream is at a temperature above 500° C.;
• b) introducing the heated feed stream into a reaction zone under conditions effective for catalytically cracking the heated feed stream to produce a reformed stream and a flue gas stream, wherein the reformed stream comprises hydrogen, carbon monoxide, and unreacted methane;
• c) introducing the reformed stream in the presence of steam to a shift conversion unit that is configured to produce a shifted gas stream comprising hydrogen and carbon dioxide;
• d) purifying the shifted gas stream to produce a hydrogen product stream and a tail gas;
• e) capturing CO2 from the shifted gas stream or from the tail gas stream;
• f) storing liquid ammonia in a single storage vessel;
• g) vaporizing the liquid ammonia to create a gaseous ammonia stream;
• and
• h) using at least a portion of the gaseous ammonia as reformer fuel and using at least a portion of the gaseous ammonia as reactant for the reduction of NOx of the flue gas stream.