A system (1, 1A) for manufacturing an aromatic compound according to the present invention includes: a first manufacturing device (2) that synthesizes a target substance from natural gas; a second manufacturing device that synthesizes an aromatic compound by a catalytic reaction from the natural gas and supplies a mixed gas mainly including unreacted methane and by-product hydrogen to the first manufacturing device (2) to manufacture the target substance; and a hydrogen separation device (3, 3A) that separates hydrogen from purge gas generated from the first manufacturing device (2) and supplies the same to the second manufacturing device (4, 4A) to regenerate the catalyst used for the catalytic reaction.

Provided is a novel production system that does not involve, or can minimize, the transport of liquid ammonia in the production of an organic compound or the production of a microorganism by microbial fermentation. A production system for an organic compound or a microorganism includes: an ammonia synthesis apparatus in which an ammonia-containing gas is synthesized by reaction of a source gas containing hydrogen and nitrogen in the presence of a supported ruthenium catalyst; and a culture apparatus that cultures a microorganism having organic compound productivity using ammonia originating from the ammonia-containing gas obtained by using the ammonia synthesis apparatus.

Ammonia synthesis system including an ammonia synthesis reactor; two or more catalyst beds included in the ammonia synthesis reactor; one or more backflow prevention plates disposed, downstream from each of the catalyst beds except not below a lowest catalyst bed of the two or more catalyst beds, and preventing a gas backflow; distribution devices disposed upstream from each of the two or more catalyst beds and distributing gas to the catalyst bed;

hydrogen gas supply lines arranged to supply hydrogen gas to each of the distribution devices; and at least one microwave heating device for emitting microwaves to each of the two or more catalyst beds, and further including a nitrogen gas supply line disposed to supply nitrogen gas to a top-most distribution device of the distribution devices.

Embodiments of the disclosure pertain to the conditioning of the purge gas stream in an NH.sub.3 synthesis plant comprising a water electrolysis unit to produce a H.sub.2 stream, ammonia synthesis loop, and a treatment section for treating purge gas at 10-70 bar(a) using scrubbing and membrane separation.