Ethanol Fuel Blending in Petroleum Refineries: An Environmental and Operational Assessment Using Simulation and Optimization

Abstract

Methyl tert-butyl ether (MTBE) has long been used as an octane enhancer in gasoline due to its high octane number (118), compared to the 91–98 grades of sold gasoline. However, MTBE poses significant environmental and health risks, particularly groundwater contamination. Worldwide, nations have replaced or reduced MTBE use by blending ethanol, a renewable and cleaner alternative that offers several benefits, including reduced emissions and improved sustainability. Despite ethanol’s promise, two primary challenges hinder its widespread adoption: (a) ethanol has a slightly lower octane number (108) compared to MTBE, which may reduce engine performance unless refiners make compensatory adjustments; (b) regions like the Middle East face limited arable land and logistical barriers, complicating ethanol production and implying reliance on ethanol imports. This study aims to identify practical and scalable strategies to support the transition from MTBE to ethanol-blended gasoline. It focuses on reducing the quality gap through refinery optimization and addressing logistical and supply chain challenges associated with ethanol integration in regions with limited agricultural resources.To tackle the first challenge, simulation and optimization techniques using preliminary refinery data were applied to assess adjustments that can compensate for ethanol’s lower octane number. To address the second challenge, a strategic roadmap was developed based on secondary data and literature review to propose supply chain and logistics solutions for non-agricultural regions. Simulation results show that the octane number of the gasoline blend can be improved from 92 to 100 through targeted refinery adjustments and ethanol integration, representing an approximate 8.7% increase in octane rating. This enhancement improves anti-knock performance, supporting more efficient and stable engine operation. For logistical challenges, the study identifies strategies such as optimization of blend scheduling and inventory management to enable efficient ethanol integration in regions lacking arable land. The transition from MTBE to ethanol-blended gasoline is both feasible and beneficial when supported by refinery optimization and logistics planning. This study provides actionable strategies for policymakers, supply chain managers, and refinery operators to overcome performance and infrastructure challenges, contributing to cleaner fuel production and advancing global sustainability goals.

Date of Award	2025
Original language	American English
Awarding Institution	HBKU College of Science and Engineering