Simulation of Nigerian Crude Oil Types for Modular Refinery (Topping Plant) Operations

This research study focused on the need to curb scarcity and importation of petroleum finished products in oil-producing nation Nigeria through the operation of conventional modular refineries in conjunction with major refineries operating efficiently. Hence, the study focused on the suitability and operations of conventional modular refinery processes by considering twenty different types of Nigerian crude oil for crude oil assay analysis and classification using Aspen Hysys. The crude oil assay results categorized the twenty Nigerian crude oil types as light and medium sweet crude, while based on recovery volume percent at a true boiling point of 370℃, the twenty crude oil types were categorized into Group A (crude oil with recovery volume above 80%), Group B (crude oil with recovery volume between 70% and 79%) and Group C (crude oil with recovery volume below 70%) respectively. Besides, light and medium sweet oil types were simulated in a conventional modular refinery (topping plant) at different numbers of column trays (25, 29, 35, 40 and 48) to determine their product yield. Based on product yield and equipment costs at different numbers of tray columns, a modular refinery with twenty-nine column trays was applied in this study. Thus, twenty Nigerian crude oil types were simulated in a conventional modular refinery of 30,000 barrel per day capacity and twenty-nine column trays respectively to evaluate their product yield and tray compositions.

30,000 bpd Capacity Modified Modular Refinery Operations in Nigeria

The study investigated and classified twenty Nigerian crude oil types based on their products recovery volume at true boiling point temperature of 370&#730C using crude oil assay analysis data into Group A (crude oil with recovery volume above 80%), Group B (crude oil with recovery volume between 70% and 79%) and Group C (crude oil with recovery volume below 70%) respectively. Thus, twenty Nigerian crude oil types were simulated in a modified modular refinery (modified topping plant) of 30,000 bpd capacity and twenty-nine (29) column trays number using Aspen Hysys software. Furthermore, the residues from the conventional modular refinery were processed as feedstock or precursor into the hydrocracker reactor attached to the stripping section of the modified modular refinery to yield more valuable products of liquefied petroleum gas, naphtha, diesel and bottom (residue). The simulation results of the modified modular refinery were compared with conventional modular refinery in terms of their residual yield percentage as Nigerian Brass 2012 of API 40.62, recovery volume 88.78%, yielded residue of 11.22% and 1.29% for conventional modular and modified modular refineries respectively while Okoro 2012 of least API 23.54, recovery volume 57.84%, yielded residue of 42.16% and 4.92% for conventional modular and modified modular refineries respectively. Thus, the residual or bottom product issue associated with operational process of conventional modular refinery operations in Nigeria due to inefficient or non-operational conventional major refinery in Nigeria has been resolved to minimum or least amount with the operational process of modified modular refinery operations in Nigeria.