Application of 3a molecular sieve in drying of ethanol - water mixture in liquid phase

This study was conducted at the department of Chemical and Mining Engineering aiming at building capacity to ethanol local manufacturers by investigating the possibility of drying the ethanol to the grade that can be used in the internal combustion engines. The adsorption column was design, fabricated with four different sampling points and installed in the Laboratory of Chemical and Mining Engineering in which ethanol of 96% purity was to be upgraded to the recommended grade of 99.5% purity. Molecular sieves of type 3A were used as packing materials in the column to enable the absorption of water from ethanol water mixture. Renewable energy sources such as ethanol fuel grade are alternative sustainable energy sources compared to fossil fuels due to their availability worldwide, low prices, do not deplete and are environmental friendly energy sources. Hence, purification of ethanol-water mixture to fuel grade is highly focused in this works. Using the designed column, the study showed promising results in which ethanol was upgraded from 96% purity to about 99.93% purity (highest point of purity) using molecular sieve of type 3A at low flow rate. However the maximum average purity at that flow rate was 99.52%compared to and 99.39% obtained high flow rate. The ethanol purity was observed to increase along the column at low and high volumetric flow rates. The breakthrough time was also observed increasing in the similar trend at low volumetric flow rate. For future studies, it was however suggested that, other parameters such as molecular sieve column diameter, temperature and ethanol retention time within the column to be investigated on how they can affect the adsorption of ethanol-water mixture of 96% (w/w) along the column. Also, the use of online sampling and Gas Chromatography analytical method was suggested in order to compare with the results obtained in this study.