The invention relates to a
urea production
system and method for absorbing
melamine tail gas, and belongs to the field of
urea production. The
urea production
system comprises a urea synthesis section, a recycle
recovery section, an
evaporation section, an
evaporation condensate
recovery section and a
desorption and
hydrolysis section; the urea synthesis section comprises a
liquid ammonia buffer groove, an
ammonia condenser, a first adsorption
tower, a
liquid ammonia preheater, a urea synthesis
tower, a carbomate preheater and an
inert gas refining purifier; the recycle
recovery section comprises a predistillation
tower, a second separation tower, a flash
evaporator, a first absorption external cooler, a first section
evaporator, a two-circulation first condenser, a two-circulation secondcondenser and a
tail absorption tower; the predistillation tower is adopted to reduce the
water volume entering into the synthesis tower, the flash
evaporator is added, the urea is concentrated, a waterpower ejector is used to vacuumize and recycle
ammonia and
carbon dioxide in the
tail gas, the ratio of H2O and CO2 is reduced, and the conversion rate of the CO2 is improved; the
system load is reduced; and under the condition of not additionally supplementing the
carbon dioxide, and the tail gas from a triamine device by condensation and absorption is taken as a
raw material of urea production.