APPLICATION OF FACTORIAL PLANNING AND RESPONSE SURFACE METHODOLOGY IN THE PRODUCTION OF BIODIESEL FROM COTTONSEED OIL (Gossipium hisutum L.)

R. H. R. de Carvalho, M. M. Conceição, A. G. Souza, E. M. B. D. Sousa

Abstract


In this work the synthesis of biodiesel from cottonseed oil (Gossipium hisutum L.) via the methyl route was carried out using a homogeneous commercial catalyst, Na-Methylat®. By means of a 23 experimental planning methodology, it was possible to assess the influence of some parameters in the process, such as oil/alcohol molar ratio, % of catalyst and temperature. The best operation conditions that must be used in actual processes, typically a 1:8 oil/alcohol molar ratio, 40 °C and 1% of catalyst, were determined by gas chromatography, reaching 96.79 % in conversion, therefore above the level established by European regulations (96.50 %). The analysis of regression showed that the only significant effect, at a confidence level of 95 %, was the changeable temperature. The biodiesel samples were analyzed by infra-red spectroscopy, identifying strong methyl ester bands that correspond to the C=O axial deformation. Physicochemical analysis indicated conformity with the specifications of Brazilian Agency of Petroleum, Gas and Biofuels, which, together with the thermal and rheological analyses, demonstrated that the biodiesel produced from cottonseed oil can be used as an advantageous alternative in substitution of diesel.

Keywords


biodiesel; factorial planning; surface response; commercial catalyst; Na-methylat®

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DOI: http://dx.doi.org/10.5419/bjpg2010-0011