The depletion of fossil energy sources has increased the demand for renewable energy. Bioethanol, which is a type of biofuel, can be used as a gasoline mixture, resulting in cleaner combustion with higher octane values as compared to conventional fuels. For bioethanol to be used as a gasoline mixture, two purification steps are required. Difficulties in the ethanol purification process are caused by the azeotrope condition of the ethanol-water mixture. To remove water from the mixture in azeotropic conditions, advanced technology is necessary. One method for separating ethanol and water that is both economical and effective is the adsorption process. This study observed adsorbent performance during a continuous adsorption process through a fixed bed column with different ethanol influent concentrations. Synthetic zeolites 3A and 4A will be examined as potential adsorbents because they have properties that result in a high adsorption capacity, they are not easily saturated, they have high selectivity, and they are easy to regenerate. This study was carried out under the bed operation condition of atmospheric temperature and pressure (20°C and 1 atm), with a 50% v/v and 10% v/v ethanol inlet concentration, which has a 10 ml/min flow rate. The results of this study are presented with a breakthrough curve, which is used to analyze adsorption performance by determining the highest ethanol effluent concentration, the adsorption capacity, and the effective adsorption time. The zeolite 3A adsorbent, which has a larger surface area and a pore diameter that is closest in size to that of water molecules, was found to have better adsorption performance, resulting in higher ethanol purity, higher adsorption capacity, and a longer saturation time as compared with the adsorption process of zeolite 4A. © 2020, International Journal of Technology. All Rights Reserved