Reduction of CO₂ Emission from Crude Oil Refining Process using Aspen Hysys Energy Analyser towards Environmental Sustainability

Crude oil is a major source of energy across the globe due to its diverse product derivatives for various industries and applications. However, the high CO₂ emissions and energy requirements associated with its refining process threaten the goal of achieving carbon neutrality. The Crude Distillation Unit (CDU) has been identified as a major unit for CO₂ emissions. Therefore, it is important to investigate the composition of feedstock (blended crude oil samples) fed to the CDU as a possible alternative to reducing CO₂ emissions associated with refining. This study uses Aspen Hysys V12 with Aspen Energy Analyser to analyze different blended feedstock from six (6) different Nigerian crude oil; Brent, Bonga, Erha, Qua-Iboe, Usan, and Yoho. The result showed that Blend 1 had the highest CO₂ emission linked to the high conversion of paraffin and naphthene to yield the highest Naphtha yield of 27.12% compared to other blends. Blend 1 also had the highest CO₂ emissions cost of $13.92 million/hr compared to $13.68 million/hr for Blend 7, with the lowest product yield. However, Blend 4 had the maximum heating energy requirement linked to its composition (mixtures of high medium and light crude) which require more reactions to maximize yield. The result revealed that individual crude's weight ratio in blended feedstock significantly increased Naphtha yield and affects CO₂ emissions. Thus, blended feedstock composition will affect product yield, energy consumption, and CO₂ emission due to the different compositions of individual crude. Therefore, to achieve the carbon neutrality goal, CO₂ emission from individual crude oil needs to be investigated, develop a new model for optimum blending with fewer emissions and the CO₂ emission cost should be added to blended feedstock price or individual crude cost to ensure a balance.