Supercritical extraction of long chain n-alcohols from sugar cane crude wax

We have studied the supercritical CO2 extraction of long chain alcohols from sugar cane crude wax, a by product of sugar cane production. The aim of this work has been to determine the effect on extraction yield of some operational variables such as pressure (300–350 bar), temperature (50–100 °C) and the ratio of KOH in the saponification stage (1–20%, w/w). To assess the n-alcohol composition of the supercritical extracts the fractions were analyzed by gas cromatography (GC). Response Surface Methodology was used to obtain mathematical expressions relating the yield as a function of the operational variables studied. These correlations have permitted us to determine the best extraction conditions of the experimental range analyzed (P = 350 bar, T = 100 °C, 20% KOH/crude wax).These results were compared to those obtained by the existing industrial organic solvent multiple stage refining process. The quality of the supercritical extract was considerably superior, because of its higher n-alcohols purity, 78.24% (w/w), compared to the organic solvent extraction yield, 22.00% (w/w).