Simulation of Ammonia Production Plant by Using Aspen Hysys

Abstract

Computer assisted modeling and simulation has increasingly become popular in all fields of engineering and in particular in chemical engineering, oil & gas and petrochemical industries. Nowadays, a number of simulation software are developed and updated in order for engineers to make fast and precise calculations. Among all of the simulators, chemical engineering simulators assist a chemical engineer to simulate design and operation of a chemical equipment and plant, which saves a lot of time and money. They also enable chemical engineers to design large plants by using defined thermodynamics or other equations of state, kinetic data, practical and mathematical models and equations, and other user input data. Without simulators modeling and design of such large plants would be expensive and time consuming. The global demand for synthetic nitrogenous fertilizers has reached new heights, with the 2012 global market generating over $98.6 billion and estimated to reach $114 billion by 2018. Ammonia is used as the primary element in the production of nitrogen fertilizers. Ammonia is also applied as a fertilizer directly or is used as a feedstock in the manufacture of urea, ammonium nitrate and nitric acid. In the present thesis, ammonia plant was designed by using the chemical engineering simulators, ASPEN HYSYS (V8.8) with steady state mode using Peng-Robinson fluid package. In this thesis modeling is performed for an ammonia plant containing 6 major steps: primary and secondary reformers in order to produce the syngas used for ammonia production, high and low temperature shift conversion in order to convert carbon monoxide to carbon dioxide, removal of carbon dioxide, methanation step, syngas compression and ammonia synthesis. Heat integration for this process is done by using aspen energy analyzer.