Simulation Design And Economic Analysis Of Crude Distillation Unit In Tema Oil Refinery (Ghana)

Refining of crude oil basically consists of primary separation process and secondary conversion processes.The petroleum refining process is the separation of the different hydrocarbons present in the crude oil into useful fractions and the conversion of some of the hydrocarbons present in the crude oil into products having higher quality performance.Atmospheric distillation and vacuum distillation are the main primary separation processes producing various straight run products from gasoline to lube oils or vacuum gas oils(VGO).These products,especially the light and middle distillates such as gasoline,kerosene,and diesel are more in demand than their direct availability from crude oils,all over the world.Ghana is faced with high import of petroleum products,incessant shortage of the product and poor petroleum refining state.There is therefore the need to develop a technology in petroleum refining as a sustainable solution to these problems.This thesis focuses on the grass-root design of crude distillation unit in Tema Oil Refinery(Ghana)using Aspen Plus software and the effect of crude selection and blending on the refinery’s profit margin using the designed crude distillation unit.The Crude distillation unit was designed to process 100000 bbl/day of different feed blends of Bonga crude and Bonny light crude.The crude distillation unit is made up of the preflash tower,an atmospheric distillation tower and vacuum distillation tower.Temperature and pressure profile for the three towers were considered to know the desired product tray.In this research,two crudes were used namely Bonga crude(Nigeria)and Bonny light crude(Nigeria).Different binary combinations of these crudes were used as feed to this crude distillation unit system.The True Boiling Point curves were obtained for each binary feed to access the variation in the compositions of the feed used.For simulation,various product design specifications like naphtha,heavy naphtha,diesel,were taken into consideration based on the American Society of Testing Materials(ASTM)regulations and target temperatures for these products were also taken into considerationAfter simulation,the objective function considered was the profit function,the prices of raw materials,steam used,the power cost and income from the products were also considered to calculate the profit.This profit was calculated with products flow rate in barrels per day using the simulation results.This study shows that the refinery can achieve a maximum profit with 80:20 blends of Bonga and Bonny light crudes using the designed CDU.On the other hand,the refinery can have a lower profit with 20:80 blend of Bonga and Bonny light crude respectivelyTo sum it all,it is shown that crude oil distillation can be very profitable process when the right feed composition is chosen.