Obtenção de ésteres etílicos via transesterificação por catálise homogênea de óleo de macaúba (Acrocomia aculeata) com aquecimento por irradiação com micro-ondas

Abstract

The possible reduction of available reserves of oil, with consequent rising price and environmental impact caused by the continued use of fossil fuels have led to studies to find possible alternatives for obtaining renewable energy, which can complement the use of oil. Among these alternatives, there is the production of biofuels. In this scenario liquid biofuels derived from vegetable oils or animal, appear as promising. This paper presents the potential use of an alternative oilseed for biodiesel production: crude oil extracted from the fruit pulp of macauba palm tree; well as a methodology for homogeneous transesterification via base catalysis more efficient than the conventionally used in power plants biodiesel production: ethyl transesterification with heating by irradiation with microwaves. Accordingly test results obtained in laboratory scale are presented in two ways, first by using the conventional heating method and the second by heating by microwave irradiation. In the conventional heating process, the following parameters were evaluated: molar ratio ethanol/oil of 12:1, reaction time of 45 minutes, temperature of 30°C, variation of catalyst concentration (KOH) of 0.5, 1.0 and 1.5% w/w of oil and mechanical agitation of 200 rpm. In the process of heating by microwave radiation the following parameters were evaluated: molar ratio ethanol/oil of 12:1, variation of catalyst concentration (KOH) of 0.5, 1.0 and 1.5% w/w of oil and the change in the reaction time of 20, 40, 60, 80 and 100 s. To the conventional heating method the results indicated that the optimum conditions were content of ethyl esters of 90.18 ± 1.56% and KOH concentration of 1.5%. The method using microwave radiation showed as a best result a content of converting ethyl esters of 96.61 ± 2.32% using 1.0% of KOH and 60 seconds of reaction time. The results indicate the feasibility of using crude oil Macauba and greater process efficiency of heating by microwave radiation.