OP-II-3

OP-II-14OPTIMIZED OPERATING STRATEGY FOR INDUSTRIAL ETHYLENEOXIDE REACTORGomes V.G. 1 and Ngian K. 21 School of Chemical and Biomolecular Engineering, University of Sydney,NSW 2006, Australia, vincent.gomes@sydney.edu.au2 Huntsman Corporation Australia, Botany Rd, Sydney, AustraliaINTRODUCTIONThis work is focused on evaluating the effects of catalyst promoter and processvariables for selective oxidation of ethylene to ethylene oxide in an industrial fixedbedreactor. The multiple chemical reactions involved in the synthesis of ethyleneoxide are highly exothermic, thereby making reactor conversion, selectivity andtemperature control for the unit rather challenging. The objective is to identify andtest the critical variables to maximize the productivity of ethylene oxide product in anexisting full-scale production facility without compromising personnel safety, planthazard and equipment integrity. Our analysis was conducted by applying dynamicsimulation models to investigate and optimize the performance of the reactor.MODELLINGWe developed the governing dynamic models of the reactor with the inclusion ofmultiple reactions by deriving the species balances for the catalytic process undernon-isothermal conditions. The kinetic parameters for the model were obtained fromliterature data for our catalyst [1-3]. The sets of nonlinear kinetic rates of theepoxidation of ethylene (and other side reactions that affect the process) to ethyleneoxide over the silver catalyst are strongly coupled with heat and mass transport, andthe governing equations. The model incorporates both catalyst deactivation and theeffect of the promoter or moderating agent: 1,2-dichloroethene (DCE). The modelpredictions were validated against plant data obtained from an operating industrialethylene oxide reactor over the plant operating period of three years.RESULTS AND DISCUSSIONSOur model predictions were found to compare well with experimental data. Themodel was subsequently used to analyse process sensitivity and optimization of theoperating conditions. The catalyst temperature was found to have major effects onthe reactor performance, catalyst aging and plant safety. The inlet temperature of oil124