Method and system for producing hydrogen from ammonia cracking

Method for producing a hydrogen product from ammonia, comprising the steps of:

• providing an ammonia feed stream;
• passing the ammonia feed stream to an ammonia cracking reactor for producing an effluent gas stream comprising hydrogen and nitrogen and optionally also unconverted ammonia;
• passing the effluent gas stream to a hydrogen recovery unit for producing said hydrogen product and an off-gas stream comprising hydrogen, nitrogen and optionally unconverted ammonia;
• the step further comprising the cooling of the effluent gas stream by heat exchange with the ammonia feed stream prior to passing the effluent gas stream to the hydrogen recovery unit;
• and
• wherein prior to said step of passing the ammonia feed stream to the ammonia cracking reactor, the method is absent of a step of passing the ammonia feed stream to an ammonia pre-cracking reactor for producing a partly converted ammonia feed stream comprising ammonia, hydrogen and nitrogen.

System for producing a hydrogen product from ammonia, comprising:

• at least one pre-cracking reactor, arranged to receive an ammonia feed stream;
• an ammonia cracking reactor arranged to receive the partly converted ammonia feed stream for producing an effluent gas stream comprising hydrogen and nitrogen and optionally also unconverted ammonia;
• a hydrogen recovery unit, arranged to receive the effluent gas stream for producing the hydrogen product and an off-gas stream comprising hydrogen, nitrogen and optionally unconverted ammonia;
• wherein the system further comprises at least one heat exchanger adapted upstream the hydrogen recovery unit for cooling said effluent gas stream by heat exchange with the ammonia feed stream.

System for producing a hydrogen product from ammonia, comprising:

• an ammonia cracking reactor arranged to receive an ammonia feed stream for producing an effluent gas stream comprising hydrogen and nitrogen and optionally also unconverted ammonia;
• a hydrogen recovery unit, arranged to receive the effluent gas stream for producing the hydrogen product and an off-gas stream comprising hydrogen, nitrogen and optionally unconverted ammonia;
• wherein the system further comprises at least one heat exchanger adapted upstream the hydrogen recovery unit for cooling said effluent gas stream by heat exchange with the ammonia feed stream;
• and
• wherein the system is absent of a pre-cracking reactor upstream said ammonia cracking reactor.