QUANTITATIVE ANALYSIS OF ETHANOL CONTENT AND KEROSENE ADULTERATION OF MOTOR GASOLINE IN ETHIOPIA, USING FOURIER TRANSFORM INFRARED SPECTROSCOP

Abstract

The automotive sector in Ethiopia is a major player of economic growth and most activities rely on it. Gasoline is the most often utilized energy source used to power automotives with internal combustion engine; as a result its demand is growing from time to time. Due to the high demand, its quality is usually compromised. Among others, ethanol and kerosene are the most commonly added substances due to their cheaper price, and surplus availability compared to gasoline. According to ISO only 10% Ethanol should be added to gasoline to reduce greenhouse gas emission. However, in many countries including Ethiopia, there is no strict control on the amount of ethanol and the presence of kerosene in gasoline. Some random investigations showed that there are illegal adulteration practices on most gasoline stations [40]. Detecting adulterants and determining ethanol content can’t be done by visual inspections due to their similarity and miscibility with the actual gasoline acquiring analytical techniques. This study aims to quantify ethanol content and kerosene adulteration in five gasoline brands from gas stations located in Hawassa city, Ethiopia using FT-IR spectroscopy. The ethanol content is determined by using the absorption peaks aroused from O-H and C-H stretching vibrations and the kerosene adulterations detected using absorption peaks in 1378 and 1460 region of IR spectrum. The later peaks are believed to be originated from the CH3 bending vibration. The results obtained by FT-IR technique showed that there is an ethanol blending practice exceeding the limit set by ISO ranging from 2% to 9% and significant kerosene adulteration has also be detected. The results suggest that there are significant kerosene adulteration and ethanol blending noncompliance with gasoline quality standards in gasoline supply chain.