Desenvolvimento de biomateriais adsortivos para purificação de biodiesel

Abstract

Biodiesel has been shown to be an attractive biofuel because it has simulated diesel yield and contributes less to the greenhouse effect. The most widely used biodiesel production process in the industry is transesterification, which requires a purification step in order for the biofuel to meet the specifications required for commercialization in relation to its contaminants. The literature presents papers that used alternative materials (clays, bamboo, sugarcane bagasse, rice hulls) and new materials with the objective of purifying biodiesel. However, a material that can be used on an industrial scale with low cost, removes other impurities, can be regenerated and reused is still sought. This finding motivated us to try to develop a biomaterial adsovente from chitosan that would act in the purification of biodiesel. For this study, the modification chosen was the esterification with tetraethyl orthosilicate (TEOS) through a sol-gel process, followed by partial oxidation with the periodate ion. Three bioadsorbents (CS, CSP1 and CSP2) were synthesized and characterized by FTIR, BET, TGA, SEM, X-ray, and Raman techniques. The efficiency of the adsorbents produced was investigated in the biodiesel purification of soybean oil produced by the methyl route, through the removal of glycerol, soap, acidity index, diglycerides and triglycerides. The results demonstrated the efficiency of the bioadsorbents in the removal of glycerol, soap, diglycerides and triglycerides. The adsorption isotherms showed that the increase in temperature from 25 ° C to 55 ° C favored the adsorption process and the faster removal kinetics was obtained with QSP2, which in one hour reached the concentration specified by the regulatory agencies (0, 02%). The adsorbents interact differently with soybean biodiesel and the samples treated with QSP2 were more resistant to oxidation because the adsorbent exhibited antioxidant properties. However, the chemical modifications carried out on chitosan corroborated the removal of glycerol and other impurities present in biodiesel.