Hydrolysis of palm oil catalyzed by macroporous cation-exchanged resin

Hydrolysis of palm oil was studied using four types of commercial H⁺-exchanged resin with acidity in the region of 5×10⁻³ eq g⁻¹ but with different pore volumes, specific surface areas, and pore diameters. The reaction was carried out in a stirred batch reactor in the liquid phase with continuous steam injection for up to 14 h. The rate of hydrolysis did not depend on total pore volume and specific surface area but did depend on pore diameter. On exchanging H⁺ with La³⁺, Co²⁺, and Na⁺, the rate of reaction decreased markedly and was dependent on the degree of exchange, demonstrating that hydrolysis was catalyzed by H⁺ sites. The activation energy for the hydrolysis of the triglycerides was estimated to be 240 kJ mol⁻¹. A procedure to estimate the rates of the different stages of hydrolysis and hence the individual rate constants of the forward and reverse reactions is described. The procedure yielded reasonable parameters for the reaction at 155°C up to 6 h of reaction time, when about 75 mol% of triglycerides was hydrolyzed.