Hydrochlorination of oleic acid: Kinetics and Henry's constant

Abstract The addition reaction of gaseous hydrogen chloride to oleic acid (hydrochlorination) was investigated. Oleic acid was placed in an autoclave chamber, into which gaseous hydrogen chloride was fed, and the reaction was carried out under batch and semiflow conditions. The hydrochlorination of oleic acid by hydrogen cloride is a gas‐liquid reaction involving the initial absorption of hydrogen chloride into a quiescent liquid, accompanied by a reaction of the dissolved gas with the liquid to form chlorostearic acid. The course of the reaction was monitored by withdrawing oil samples at 30‐min intervals and determining the iodine value, acid value, and chlorine content. The kinetics of hydrochlorination was studied at constant pressure (40 atm). The experimental data were fitted to an irreversible pseudo zero‐order rate equation with the reaction constant k=2.293×10−7 mol/cm3·s. The solubility of HCl (Henry's constant) in chlorostearic acid was estimated from two types of batch experiments, including a single and double feed of HCl. The mean Henry's constant value for physical absorption was 3218 atm cm3/mol in the pressure range of 11.2–16 atm and at a temperature of 21°C. Similar batch experiments were performed in oleic acid, and the results supported the Henry's constant value determined for chlorostearic acid.