Biodiesel from rapeseed oil, methanol and KOH. 2. Composition of solution of KOH in methanol as reaction partner of oil

The composition of the solutions of solid KOH in methanol has been measured by means of determinating the content of water in the equilibrium mixture. The dependence of the equilibrium reaction extent ξ 1 and the concentration equilibrium constant Kc on the ratio of the initial amounts of methanol and KOH containing 0.164 and 16.27 wt-% of water are determined and theoretically described. The concentration of CH 3 O ions can be calculated with these results. This value is very important for the course of the alkaline catalyzed methanolysis of rapeseed oil to biodiesel, because the methoxide ions are the true catalyst of such a transesterification. La composition des solutions de KOH solide dans le methanol et l'eau dans le melange a l'equilibre ont ete determines. La concentration de CH3O - est calculee. cette valeur est importante dans la methanolyse alcaline de l'huile de colza, les ions methoxide etant les catalyseurs de la transesterification.