Influence of Crude Oil Type on Products Quality of the Atmospheric Distillation Unit by Applying Material Flow Cost Accounting Simulation: Part A

The oil refining industry, as one of the most important sources of supply for the people of the world, needs to optimize energy. In the present study, the atmospheric distillation unit of a refinery has been selected as a case study. Using a new method of material flow cost, determining the positive and negative products and their actual valuation, the share of various costs in the unit has been demonstrated. Since about 99.3% of the total costs in this unit are related to the cost of purchasing crude oil as feedstock, the importance of purchasing crude oil in the event of crisis management and the conditions of alternatives are fully characterized. Three crude oils named Maroon, Dezful, and Mansouri were studied as alternatives for Ahwaz crude oil. The results of Maroon crude oil show that, in the same operating conditions, its substitution as the main feedstock obtains the same quality products as Ahvaz crude oil products. The products derived from Dezful crude oil shows a difference of approximately 7 to 8 degrees API. Products from Mansouri crude oil have a difference of between 20°C and 40°C at boiling point and a difference of 5° to 7°API, and with increasing temperature and feed pressure, there is no significant change in the quality of the products. The mixture of Mansouri and Dezful crude oil separately with Ahwaz crude oil does not achieve the desired quality. But proper quality can be obtained by applying changes of 10 °C to 30 °C at inlet temperature, and from 0.5 to 0.7 kg/cm2 at the pressure. Due to the same price of Ahwaz and Maroon and Dezful, there is no change in the cost of purchasing, and products of the same cost are obtained.