Design of a Plant for the Production of Ammonia and Urea Using Aspen HYSYS

Abstract

The design of a plant for the production of 1800 MT/Day of ammonia and 1400 MT/Day of urea using aspen HYSYS was carried out in this work. Ammonia is produced through the Haber-Bosch process, where hydrogen and nitrogen react in the presence of a catalyst producing mixture containing ammonia while urea is produced by the reaction between ammonia and carbon IV oxide. In this work, aspen HYSYS, chemical engineering design software was used to design and perform material and energy balance around the plant. From the design analysis performed from the software, plant production capacity of 75,063 kg/hr. of ammonia and 58,343 kg/hr. of Urea was obtained. 7,677.6 kmole/hr. of methane gas, 19,194 kmol/hr. of steam and 3,584 kmol/hr. of air feeds was used to achieve the objective. The overall reaction is exothermic, and the primary reformer process is characterized by a low pressure. Cost estimation carried out showed that the total purchased cost of equipment was $9,881,055 fixed capital investment was $64,545,522, gross annual earning was $72,422,247, and net annual income was $54,316,685 rate of return was 38.85% and payback time was 2.5 years. Safety consideration for a smooth run of the ammonia-urea plant is also presented in this work. The design of a plant for the production of ammonia and urea using aspen HYSYS was well demonstrated in this research work, since the energy and the mass balance of each component was evaluated as presented in this research. Finally, the research demonstrates the usefulness of aspen HYSYS in the design of process plant for chemical base unit.