SÍNTESE DE BIODIESEL POR TRANSESTERIFICAÇÃO ENZIMÁTICA DO ÓLEO DE BABAÇU COM ETANOL EMPREGANDO A LIPASE IMOBILIZADA NOVOZYM 435 COMO CATALISADOR.

Abstract

In this work we have studied the biodiesel production through the transesterification (alcoholise) of babassu oil with ethanol using the immobilized enzyme commercial Novozym 435 (a lipase derivative) as catalyst. To achieve this purpose we have planned a factorial design to evaluate the influence of following factors in the reaction medium: temperature, time of reaction, enzyme concentration and oil/etanol molar ratio. Though the utilization of this statistic tool we expected to identify which factor had the main influence in the reaction yield and ester concentration in the final product. We also have studied the enzyme derivative recycling and prio r treatment by its immersion in vegetable oil and pure biodiesel before several batches of reaction. The control of quality of the departure babassu oil was made thru the following analyses: acid value, iodine index, humidity and viscosity. The quality of the final product was monitored thru the physical-chemical analyses established in the resolution number 42 from the “Agência Nacional do Petróleo, Gás natural e Biocombustíveis (ANP)”. The results have unveiled that the catalyst concentration, temperature and oil/alcohol molar ratio have the main influence in the reaction yield, by the other hand, the factor period of time doesn’t have significant influence on it. The highest reaction yields has laid in the range of 85 to 88.6 % and the proposed mathematical model to estimate reaction yield can explain 87.8% of the observed data variation. Almost all the biodiesel samples had an ester concentration above 96 % and catalyst concentration and the temperature were the main effects upon this response. The data correlation obtained thru the mathematic model can explain 88.5 % the experimental data variation. The recycling tests have shown that it is viable to use them until up to 8 cycles of reaction without considerable loss of activity and the prior enzyme treatment before reaction had good results in terms of oil conversion reaching up to 96.5 % ester concentration, even though we had utilized a period of time smaller than the one used in the optimization step. The biodiesel produced quality control has shown that the samples were inside specifications established in the current law.