Solubilization of methanol and ethanol in palm oil stabilized by medium‐ and long‐chain alkanols

Abstract

Solubilization of methanol and ethanol in crude palm oil, re®ned, bleached and deodorized palm oil (RBD PO) and RBD palm olein (PO L ) was studied using medium-and long-chain alkanols (C 4 ±C 12 ). Ternary phase diagrams were constructed to determine the solubilization (isotropic) region. The results showed that methanol and ethanol are solubilized to a greater extent in an unsaturated palm olein than the saturated CPO and RBD PO in the presence of long-chain alkanols. The minima of the solubilization curves for dodecanol, decanol and octanol were 27%, 30% and 33% of alkanol respectively in the methanol system, whereas in the ethanol system, the minima for the same alkanols were found at 22%, 24% and 27%. The longer chain-length alkanol (dodecanol) requires a lesser amount (21% and 32%) to achieve miscibility compared with 53% and 57% for butanol in mixtures containing 70:30 and 50:50 wt ratios respectively. The kinematic viscosity of the isotropic solutions increases with the chain-length and percentage of alkanols. Solubilization using a PO L /methanol/ butanol system signi®cantly reduced the kinematic viscosity of PO L from 72.7 mm 2 s À1 to the value allowable for No 2 diesel fuel (1.9±4.1 mm 2 s À1) or about a 96% reduction from the initial kinematic viscosity of PO L .