Modeling of reactor — Separator column for purification of naphtha

Ammonia is essential in obtaining fertilizers like urea and NPK, which is produced from nitrogen and hydrogen. Nitrogen can be extracted from atmospheric air and hydrogen is extracted from natural gas or naphtha, where carbon and hydrogen are in the ratio of 5.45:1. Naphtha contains organic and inorganic sulphur. Hydrogen desulphurization process reduces sulphur content in naphtha as sulphur forms poison to catalyst at further stages. This process generally involves a fixed bed reactor where the catalyst absorbs sulphur present in naphtha. To increase the amount of ammonia yield from naphtha, sulphur concentration in naphtha should be reduced further. Flash drum and stripper column are integrated along with the fixed bed reactor to achieve higher ammonia yield. Mathematical modeling for fixed bed reactor, flash drum and stripper column are simulated separately and are integrated to study the dynamics of the hydrogen desulphurization process. ARX, ARMAX and transfer function models are identified for the process andare validated with real time data.