AMMONIA SYNTHESIS SYSTEM AND AMMONIA PRODUCTION METHOD

An ammonia synthesis system according to the present invention includes: an ammonia synthesis reaction part (10) that synthesizes ammonia from nitrogen and hydrogen; an ammonia cooler (20) that cools an ammonia-containing gas discharged from the ammonia synthesis reaction part (10); a gas-liquid separator (30) that separates ammonia liquefied by the ammonia cooler (20) and a circulating gas; and an ammonia synthesis gas supply part (40) that supplies a nitrogen gas and a hydrogen gas. The circulating gas is supplied to the ammonia synthesis reaction part, and the concentration of ammonia gas in the circulating gas supplied to an ammonia synthesis part is 3 volume% or higher. In an ammonia production method according to the present invention, ammonia is produced by reacting nitrogen and hydrogen under the condition where the reaction pressure is 10 MPa or less by using a circulating gas in which the concentration of ammonia gas is 3 volume% or higher and an ammonia synthesis catalyst. With the present inventio