Estudo do processo de purificação de biodiesel de soja com adsorvente de baixo custo

Abstract

With the growing global awareness of environmental protection and the pollution that the use of hydrocarbon causes, biodiesel industry flourished and established. A major existing problem is the technique used in the ester phase purification, called wet purification (applying water and carrying out washings) which is a contradiction for a product less aggressive to the environment and with a sustainable appeal. This is justified because water is a scarce and non-renewable natural resource so its use creates a new problem to be solved by producers, increasing their economic and environmental costs. Due to that, the search for alternatives to this method is much needed, making dry purification (using adsorbent materials) an interesting possibility. The main objective of this work is to highlight the existing adsorbents materials and investigate the possibility of using materials considered waste and, hence, adding value to them. Thus, rice husk is the focus of this research which will investigate its natural adsorptive capacity and the possible use of acid treatment in different concentrations and reaction times to improve it. More than that, quantification of minimum mass required to reach or approach the standards required by the Brazilian National Petroleum Agency (ANP) will be made. Experiments involves the addition of a relative mass percentage of rice husk in a given mass of ester phase, with subsequent quantification of free glycerol content, free, combined and total alkalinity, specific gravity at 20 °C and kinematic viscosity at 40 °C. It was identified, therefore, that rice husk has a potential to be a low-cost adsorbent for biodiesel, with great efficiency when used without treatment and in quantities of 5 % or 10 % by weight. Also, with 5 % and treatment with 4N sulfuric acid for two hours it reached very similar reduction levels when compared with the natural rice husk. Furthermore, analyzes have shown that rice husk does not cause any meaningful change in biodiesel properties