AMMONIA DECARBONIZED-2500 process for producing low-carbon ammonia from natural gas

Abstract

This invention relates to a technology for producing low-carbon ammonia by converting natural gas into synthesis gas containing hydrogen and nitrogen through primary and secondary reforming. Carbon dioxide is removed from the obtained synthesis gas for purification, and the purified synthesis gas is methane-conjugated before ammonia synthesis is carried out using a high-pressure catalytic method. The technical advantages are that the entire amount of synthesis gas from the process line is used for ammonia synthesis, and this process provides sufficient cooling to support the ammonia recovery stage.

Claims

[Claim 1] A method for producing ammonia from natural gas, comprising: heating the natural gas and vapor and subjecting them to primary reforming; subjecting the obtained inverted gas to secondary reforming operating with a mixture of vapor, air, and oxygen; then sending the obtained inverted gas to carbon oxide conversion; removing carbon dioxide from the obtained synthesis gas; methaneating the purified synthesis gas; then, downstream of ammonia recovery, using purge gas as fuel to increase the temperature of the natural gas and vapor while synthesizing and recovering ammonia to be transported as the final product; after methaneating, compressing the synthesis gas and sending it to ammonia synthesis; downstream of ammonia recovery, reducing the pressure of the purge gas by expansion; and ammonia recovery using a heat transfer medium cooled as a result of the expansion of the purge gas, wherein ammonia condensed from the purge gas during expansion is transported as the final product. [Claim 2] The method according to claim 1, characterized in that a portion of the purge gas is recirculated to a compressor, and then recirculated together with the synthesis gas for ammonia synthesis. [Claim 3] The method according to claim 1, characterized in that the heat of the conversion gas downstream of the secondary reforming is used for the primary reforming. [Claim 4] The method according to claim 1, characterized in that condensates are extracted from flue gas generated during fuel combustion to heat the natural gas and steam, and then sent downstream of secondary reforming to steam generation utilizing the heat of the converted gas, and the resulting steam is used in the primary reforming and as part of the mixture of steam, air and oxygen for the secondary reforming. [Claim 5] The method according to claim 1, characterized in that the purge gas downstream of ammonia recovery and depressurization is used as fuel to raise the temperature of the mixture of steam, air, and oxygen.

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