| 摘要 |
An integrated ammonia and urea plant comprises: (1) an ammonia syngas unit including primary and autothermal reformers, a shift converter and a CO2 removal unit, for reacting hydrocarbon feedstock with steam and air to form a CO2 stream (I) and a syngas makeup stream (II) of H2 and N2; (2) an ammonia conversion unit including a synthesis loop for mixing a recycle stream (III) with (II) to form an ammonia converter feed stream (IV), feeding (IV) to an ammonia synthesis reactor, recovering an ammonia stream (V) from the effluent (VI) from the syngas reactor, recovering a purge stream (VII) from (VI) and forming (III); (3) a urea unit for reacting (I) with (V) to form urea at above 14 MPa in the presence of a passivating amt. of O2 and of a minor amt. of N2; the unit includes a high pressure scrubber to separate O2 and N2 from a urea-contg. stream (VIII) to form a high pressure N2-contg. stream (IX) above 14MPa contg. minor amts. of O2, CO2 and ammonia; and (4) a line for introducing (IX) with compressed air to the autothermal reformer. The novelty is the introduction of (IX) to the autothermal reformer. Also claimed is a method for integrating the operation of ammonia and urea plants using the disclosed plant. |
