Thermal Polyaspartate Anion, a derivative biopolymer of aspartic acid, was used to remove water residues of both diesel and jet liquid hydrocarbons fuels. In this work a novel and simple method for improving the properties of fuel is reported. Different masses of TPA polymer have been mixed with a constant volume of fuel and the humidity concentration, the heat of combustion, the flash point as well the cetane index were measured according to the ASTM standard protocols. For the evaluation of the effect of the polymer additive in the physicochemical properties of the fuel, a number of ASTM standard measurements were followed. In addition, Fourier transform infrared spectroscopy (FTIR), temperature-modulated differential scanning calorimetiy (TM-DSC) and thermogravimetric analysis (TGA) were used in order to evaluate the interactions between water and polymer. The removal of the humidity/water is requisite in fuel technology because of the numerous problems related to the presence of water, such as: corrosion of engine parts, pipelines and storage reservoirs, ice formation at very low temperatures and turbidity growth due to impurities. Water removal improved the physicochemical properties of both studied fuels, diesel and jet, up to 463 j/g and 1040 j/g for the heat of combustion, 28.2% and 71.4% for the total acid number and up to 39.4% and 25.7% for humidity, for diesel fuel and jet fuel respectively. Overall, the proposed method can be used in a simple fuel cleaning process using a metal mesh vessel of Thermal Polyaspartate Anion (WA) polymer. The polymer can be replaced and re-generated as often needed. (C) 2012 Elsevier Ltd. All rights reserved.