Ammonia cracking process and apparatus for improved hydrogen recovery
AssigneeUop LLC
InventorBradley Russell
Life of this patent
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Abstract
Methods for producing hydrogen from ammonia are described. The methods involve the use of a two-stage hydrogen PSA configuration. The effluent stream from the ammonia cracking reaction zone is sent to the first hydrogen PSA unit where it is separated into a high purity, high-pressure hydrogen stream and a low-pressure tail gas stream. The high-pressure hydrogen stream can be recovered. The low-pressure tail gas stream is compressed and sent to the second hydrogen PSA unit where it is separated into a second high-pressure stream and a second low-pressure tail gas stream. The second high-pressure hydrogen stream can be recycled to the first hydrogen PSA unit for further separation.
Claims20
A method of producing hydrogen from ammonia comprising;
- cracking an ammonia feed stream comprising ammonia in an ammonia cracking reaction zone to produce a cracked effluent stream comprising hydrogen and nitrogen;
- separating the cracked effluent stream in a first hydrogen pressure swing adsorption (PSA) unit into a first high-pressure hydrogen stream and a first hydrogen depleted tail gas stream comprising a portion of the hydrogen and the nitrogen;
- compressing the first hydrogen depleted low-pressure tail gas stream in a compressor to form a compressed tail gas stream;
- recycling at least a portion of the compressed tail gas stream to the first hydrogen PSA unit;
- and
- recovering the first high-pressure hydrogen stream.
An apparatus for producing hydrogen from ammonia comprising:
- an ammonia cracking reaction zone having an inlet and an outlet,
- a first PSA unit having an inlet, a high-pressure hydrogen outlet, and a low pressure tail gas outlet, the outlet of the ammonia cracking reactor in fluid communication with the inlet of the first PSA unit;
- and
- a compressor having an inlet and an outlet, the compressor inlet in fluid communication with the low-pressure tail gas outlet of the first PSA unit, and the compressor outlet in fluid communication with the inlet of the first PSA unit.
Dependencies are inferred from the claim text.