Study of an ethylic biodiesel integrated process: Raw-materials, reaction optimization and purification methods

No studies are reported on ethylic biodiesel integrated processes, considering raw materials, reaction optimization and product purification. The present study aims to: i) select key variables for experimental optimization of ethanolysis using a virgin vegetable oil; ii) perform an optimization study using a waste oil; and iii) evaluate the effectiveness of water free purification methods. Sunflower oil ethanolysis was conducted at different temperatures (30 – 80 °C), catalyst concentrations (0.3 – 2 wt.%), reaction times (0.5 – 4 h) and ethanol: oil molar ratios (2:1 – 12:1). Optimization experiments on waste oil ethanolysis were performed at different temperatures (30 – 50 °C) and ethanol: oil molar ratios (6:1 – 12:1), during 1 h and using 1 wt.% catalyst. Quality parameters were measured according to EN 14214. A cation-exchange resin and a ceramic membrane were evaluated for water-free purification. Regarding sunflower oil ethanolysis, when successful, conversion ranged from 75.2 to 97.7 wt.%. Using both oils under optimized conditions (45 °C, 6:1 ethanol:oil molar ratio), a product with a very high purity (> 98.0 wt.%) was obtained after water washing purification. The 0.1 μm ceramic membrane was more effective than the cation-exchange resin, but it was not possible to obtain a good quality product using both methods.