Solvents for cashew nut oil extraction and environmental compatibility.

Abstract

CNLS is an important by-product of cashew nut processing industry. The industrial practices of extraction impose risks to the environment and to the human health. In the present study alternative solvents were investigated (isopropanol, ethanol and ethanol 96%) to hexane, usually employee. Hexane replacement has foundation in the principles of the “green chemistry”. There are also advantages for workers environmental health and in context of environmental management. Solvent substitution may incorporate value to the technical culture and give a greater environmental competitiveness. The experimental investigation for substitution of hexane by a solvent with larger environmental compatibility showed that the mean CNLS recovery increased with the Polarization Index (PI) of the solvents. The same occurred with regard to Vapor Heating. Results favored the use of ethanol (pure or at 96%). Also, the best extraction index as a function of the number of extraction cycles was reached the ethanol. In spite of the advantages of the alternative solvent modifications in the extraction plant are necessary, and demand a new technological profile. As a final remark ethanol possesses lower toxicity and flammability, higher biodegradation rate, and it is easy to be bought at a low cost compared to hexane. It is also a solvent with better environmental compatibility, compared to hexane.