Conversion of methanol to light olefins on SAPO-34: kinetic modeling and reactor design

Conversion of Methanol to Light Olefins on SAPO-34: Kinetic Modeling and Reactor Design. (December 2003) Saeed M. Al Wahabi, B.S., King Saud University; M.S., King Saud University Co-Chairs of Advisory Committee: Dr. Gibert F. Froment Dr. Rayford G. Anthony In this work, the reaction scheme of the MTO process was written in terms of elementary steps and generated by means of a computer algorithm characterizing the various species by vectors and Boolean relation matrices. The number of rate parameters is very large. To reduce this number the rate parameters related to the steps on the acid sites of the catalyst were modeled in terms of transition state theory and statistical thermodynamics. Use was made of the single event concept to account for the effect of structure of reactant and activated complex on the frequency factor of the rate coefficient of an elementary step. The Evans-Polanyi relation was also utilized to account for the effect of the structure on the change in enthalpy. The structure was determined by means of quantum chemical software. The number of rate parameters of the complete reaction scheme to be determined from experimental data is thus reduced from 726 to 30. Their values were obtained from the experimental data of Abraha by means of a genetic algorithm involving the Levenberg-Marquardt algorithm and combined with sequential quadratic programming.