Technical Transformation Of Decarburization Unit In Ammonia Synthesis Plant

This dissertation focuses on the process optimization and technical transformation of synthetic ammonia process based on SINOPEC QILU CO., second fertilizer factory moving to Sichuan dazhou project. Benfield decarbonization system model was established and developed on the basis of Aspen plus simulation and necessary mathematical calculation. The simulated calculation includes determining state equation calculation method, and analyzing chemical mechanism and the energy saving effects in Benfield process of CO2absorption and regeneration.Based on practical experience and abundant theoretical analysis, the simulation calculation optimizes the unreasonable part of the original process. Through adding heat exchanger and flash tower/vapor scrubber, the energy consumption of low pressure steam when regenerating the regenerated liquid reduces from1000kCal per stere CO2to728kCal per stere CO2; Meanwhile, the percentage content of hydrogen which goes to the carbamide procedure decreases from1.1%to0.3%. After the addition of the new type of activator AMP to the original absorber, the purity of CO2on top of regeneration tower improves from98.74%to99.48%; Furthermore, the recovery rate of CO2turns out98.33%and99.92%respectively, so that the amount of the feed gas going to the carbamide procedure is enhanced and the productivity of the system is enlarged.