Monday, April 30, 2007

Evaluation of cashew apple juice for the production of fuel ethanol

Álvaro Daniel Teles Pinheiro1, Maria Valderez Ponte Rocha2, and Luciana R. B. Goncalves1. (1) Chemical Engineering, Universidade Federal do Ceará, Campus do Pici, Bloco 709, Fortaleza, Brazil, (2) Chemical Engineering, Universidade Federal do Rio Grande do Norte, Av. Sen. Salgado Filho 3000, Natal, Brazil

The role of ethanol as a less pollutant fuel or as additive to internal combustion gasoline engines has been generally recognized. Brazil, due to a project called “Proálcool”, has become the world largest ethanol producer via fermentation of sugarcane. However, in the northeast of Brazil, the volume of ethanol produced does not represent an important amount compared to the national production. So, the optimization of alternative low-cost processes is imperative. In the state of Ceará, the cashew agro industry has an outstanding role in the local economy. However, only 12% of the total peduncle, the part of the tree that connects it to the cashew nut, is processed and it does not play an important role to the economy of the state. Furthermore, the majority of the cashew apple production spoils in the soil. Those facts, together with its rich composition (reducing sugars, fibers, vitamins and minerals salts), turns cashew apple juice (CAJ) into an interesting and inexpensive (R$1,00/Kg) culture medium. Therefore, the aim of this work is to investigate the potential use of this raw material for the production of fuel ethanol. A commercial strain of Saccharomyces cerevisiae was selected and the experiments were conducted in a batch bioreactor. The process was monitored by measuring glucose, fructose and ethanol concentrations by HPLC, as well as biomass concentration.