Determination of Hansen solubility parameters for sugarcane oil. Use of ethanol in sugarcane wax refining

Abstract

Currently, the refining of sugarcane wax is carried out with 95% v/v ethanol as solvent. This process has a high rate of ethanol consumption thus, the main objective of this work was to corroborate the feasibility of 95% v/v ethanol as a solvent in the refining of sugarcane wax. The suitability of its performance over other organic solvents was evaluated through the relative energy difference (RED) determined from Hansen solubility parameters (HSPs) of sugarcane oil, which were calculated using HSPiP software. HSPs turned out to be δD = 16.24 MPa½, δP = 3.21 MPa½ and δH = 10.34 MPa½, similar to those reported for pine resin and castor oil. The best solvent was 1-decanol. 95% v/v ethanol turned out to be a bad solvent. Absolute ethanol had a RED value of 0.993, which made it a better candidate since it could reduce consumption rates, and constituted an eco-friendly solvent produced in Cuba for the refining process.

Obtaining a Fraction of Sugarcane Wax Rich in Policosanol by Using Ethanol as Solvent: Results Interpretation through Hansen’s Solubility Theory

“…The temperature effect and other thermodynamic considerations explain why ethanol at low temperature is a good solvent for the wax–oil fraction 16 and is considered a bad solvent for the wax fraction evaluated at 25 °C. 23 On increasing the temperature, it becomes a good solvent.…”

“…For an evaluation of the factors that affect the solubility of sugarcane wax and its components in ethanol, it is necessary to consider HSPs and the influence of temperature on them. Hansen’s solubility parameters theory is explained in the literature and several authors mentioned above ,− have detailed its application. Solute–solvent miscibles are those that are close in a tridimensional space of HSPs.…”

“…Usually, either the refining or the fractionation process of sugarcane wax requires the identification of appropriate solvents for the separation of these fractions, so recent studies have been directed toward the determination of the Hansen solubility parameters (HSPs) of sugarcane wax fractions to identify the best solvents related to each of them. 16 …”

“…Hernández et al 16 report the use of ethanol as a good solvent for sugarcane oil extraction because it is inside the Hansen solubility sphere, 17 as was determined experimentally for this wax fraction. The results obtained by several authors 18 − 22 considering the feasibility of the use of ethanol for vegetable oil extraction, as well as the miscibility of some of them with ethanol, also ratified its use in the extraction of these compounds.…”

“…Usually, either the refining or the fractionation process of sugarcane wax requires the identification of appropriate solvents for the separation of these fractions, so recent studies have been directed toward the determination of the Hansen solubility parameters (HSPs) of sugarcane wax fractions to identify the best solvents related to each of them. 16 The separation of sugarcane wax fractions is directly related to their commercial use. Although sugarcane wax has several uses in both food and cosmetic industries, its consumption as raw material for the extraction of a mixture of higher fatty alcohols, called policosanol, where octacosanol is the principal component, remains the main market interest, given its pharmacologic and nutraceutical value.…”