FIELD: chemical equipment.
SUBSTANCE: present invention relates to an ammonia synthesis system with low emission of carbon dioxide and control of urea disequilibrium. Disclosed is ammonia synthesis system with low emission of carbon dioxide and control of urea disequilibrium, it includes subsystem of two-stage conversion of natural gas, subsystem of purification, subsystem of fresh gas drying and subsystem of ammonia synthesis and cooling. Initial natural gas passes through a subsystem of two-stage conversion of natural gas, generating fresh gas and carbon dioxide. Fresh gas is supplied to fresh gas drying subsystem for moisture removal. In addition, in accordance with the production of carbon dioxide, part of dry fresh gas is used for regeneration of molecular sieve and further supply back to subsystem of two-stage conversion of natural gas as additional gas for combustion. Remaining fresh gas passes through the ammonia synthesis and cooling subsystem to obtain a liquid ammonia product. At that, fraction of fresh gas used for molecular sieve regeneration in fresh gas drying subsystem is 8–10% of fresh gas volume, and the ratio of molar carbon dioxide to molar output of liquid ammonia is 1:2.
EFFECT: achieving carbon balance of ammonia during urea production.
8 cl, 1 dwg, 1 ex
