Simulation and economic analysis of crude distillation unit using aspen plus

Abstract

Crude Distillation Unit (CDU) system is considered to be the most fundamental process of petroleum refining. This work aimed at the general thumb rules for the grass-root design of crude distillation unit (CDU) using aspen plus. Crude distillation unit system constituted a pre-flash tower, an atmospheric distillation tower and a vacuum distillation tower. Temperature and pressure profiles for all the three towers were considered to know the desired product tray. Here two crudes were used namely BOMBAYHG (Bombay crude), ARABY (Arabian Light Crude). Different binary combinations of these crude were used as feed to this crude distillation unit system. The True Boiling Point curves were obtained for each binary feed were obtained to access the variation in the compositions of the feed used. For simulation various product design specifications like for naphtha, HNAPTHA, diesel were considered based on the ASTM regulations and target temperatures for these products were also considered. After simulation, the objective function considered was the profit function, the prices of all raw materials, the steam used, the power cost and the income from the products were considered to calculate the profit. This profit was calculated with flow constraints on steam used in the towers. This work provides raw understanding regarding the feed selection and feed composition and can be helpful for refinery planning and scheduling of refinery assignments. Quality of products can be ensured for certain products whose design specifications were considered and rest could not be judged.