Kinetic Study of Potassium Malonate Synthesis from Potassium Acetate, Carbonate and Carbon Monoxide under Pressure

Abstract

Synthesis of potassium malonate from potassiym acetate, carbonate and, carbon monoxide has been studied kinetically under pressure in a molten potassium formate solution.
The initial rate of malonate formation is of the first order with respect to carbon monoxide pressure and mole ratio of acetate/carbonate in the charge.
Potassium carbonate reacted with carbon monoxide under malonate producing conditions to give a complex, which was decomposed in water into potassium formate and bicarbonate. The addition of malonate and formate, the reactyion products, into the system had no effect on the malonate formation.
Based on these results following mechanism has been proposed: potassiym carbonate reacts firs with carbon monoxide to form a complex as an intermediate, with which acetate converts into dipotassium malonate and potassium formate.
The rate equation and equilibrium constant given by apparent equilibrium constant of the complex formation and rate constants have been determined at 265, 280 and 300C to be respectively. The overall activation energy and apparent heat of complex formation are found to be 26.1 kcal and 19.6kcal, respectively.