(629ab) Behavioral Analysis of Heterogeneous Catalysts Type Zeolite (HZSM-5 and HBETA) on the Transesterification of Soybean Oil Modified with Fatty Acids

In this work we studied the transesterification of commercial soybean oil enriched with fatty acids (0.25 wt% oleic acid and 0.25 wt% linoleic acid) using HZSM-5 and HBETA zeolite as the catalysts. The purpose of this project is to analyze the behavioral and feasibility of using a solid acid catalyst such as HZSM-5 and HBETA zeolite in the transesterification of modified soybean oil, because the traditional homogeneous catalyst most commonly used (NaOH) is not recommended if the oil has a content greater than or equal to 0.5% by weight of fatty acids, since it produces an emulsion of soap and biodiesel. To carry out the reaction a stirred glass reactor was used. The charge to the reactor consisted of 50 grams of oil, using a molar ratio of methanol/oil = 14 / 1. Commercial HZSM-5 and HBETA zeolite (4 grams) with a Si0₂/Al₂O₃ molar ratio of 80 and 75 respectively (Zeolyst) was used in the study. The reactor was operated at 1 atm and  temperature of 75 ºC. The stirring speed was 1000 rpm and the reaction was carried out within 8 hours. The conversion of fatty acids to methyl esters varied from 2 to 5% at the reaction conditions. However the distribution of product of Fatty Acid Methyl Esters it was diferent  those who always obtained with homogeneous catalyst (NaOH). Saturated and Unsaturated chains of Fatty Acid Methyl Ester of more than 18 carbons were the main products obtained with this type catalysts.