| 摘要 |
A process to produce ammonia from a hydrocarbon feedstock, involving basically the following steps: Dividing the feedstock into two fractions, Subjecting the first fraction to a primary steam reforming reaction, at high pressure and moderate temperature, Combining the effluent from the primary reforming with the second fraction of the feedstock, and subjecting the mixture thereof to a secondary adiabatic reforming reaction with an amount of air in excess to that needed for ammonia synthesis, Subjecting the synthesis gas produced to a CO shift conversion reaction, and then to CO2 removal by solvent scrubbing, while the gas released by pressure letdown of said solvent is preferably recycled back upstream of the secondary reforming, Methanation of the residual carbon oxides, Removing the excess nitrogen present in the gas by cryogenic separation, Compressing and feeding the final synthesis gas into an ammonia synthesis loop, Recycling the purge gas from said ammonia synthesis loop to upstream the cryogenic separation. |
