Petroleum distillation simulation: Investigation of the effect of process parameters on product composition

World need for energy has been on a continuous rise in parallel to the rapidly-growing industrial demand around the world. Consequently, distillation and fractionation of crude oil is of paramount importance today, as the crude oil is the basis of many fuels that are used as the main energy source in so many industries. The most common and effective technique used today in separation of crude oil into its components and to fuels usable in the industry is distillation. Distillation in essence is a separation technique utilizing the different boiling points, evaporation tendencies, of a mixture's components. Among the final products from distillation of crude oil, gasoline, fuel oil, diesel, jet fuel, asphalt, kerosene and machine oils can be counted. One of the most energy-intensive units in a crude oil refinery are the distillation columns, where the crude oil is distilled into its main fractions. It is therefore a major research and development task to ensure the optimal operation of these columns, serving to both minimizing the operational costs and safeguarding the world's energy resources. The operating conditions in a distillation column is set by many parameters that affect the flowrate and composition of the products. In this work, a simulation has been created for an atmospheric distillation unit and the effects of varying process parameters on the column's operating conditions and the product compositions have been studied. The software used to create the simulation is ASPEN Plus V8.6 and the process parameters selected for study are feed location, feed temperature and feed flowrate. It is observed that increasing the feed flowrate results in a decrease of the products' and dip flowrates, as the heat input is not increased in parallel, lowering the distillation performance. Another finding is that the feed increases the temperature and flowrates of the products drawn from stages close to the feed location. Finally, only increasing the feed temperature without any changes to feed flowrate affects the product compositions, while the flowrates remain essentially flat. The products and the dip are composed of heavier components, while more light components leave the column from the top stream.