A PHYSICOCHEMICAL METHOD TO CALCULATE TIME-DEPENDENT REACTION MIXTURES

A method is proposed to calculate multicomponent chemical reaction mix tures as a series of sequential, time-dependent thermochemical states. The procedure is based on the two general principles of physical chem istry, viz., decreasing Gibbs-energy for a natural process and the exp onential Arrhenius rate law for the overall reaction kinetics. The cal culation is performed in repeated sequences for a closed system elemen t with known heat transfer to its surroundings. The temperature of eac h sequential reactor element is determined by a Gibbs-energy minimizat ion routine (SOLGASMIX) connected to the closed system enthalpy balanc e iteration. The extent of overall reaction is limited by the Arrheniu s kinetics, while the possible side reactions may reach equilibrium. T he mass balance relations forming the subsidiary constraints of the La grange method are modified to facilitate the Gibbs-energy minimization for the intermediate ''reactor states''. The well-known reaction of t itanium (IV) chloride oxidation to titanium dioxide with such side rea ctions as chlorine dissociation and oxychloride formation is given as a calculational example.