Boreskov Institute of Catalysis of the Siberian Branch of Russian ...

PP-II-10CALCULATION OF INDUSTRIAL CATALYTIC REACTORS FORTHE SYNTHESIS OF NON-OZONE-DEPLETING SUBSTANCESN.G. Zubritskaya, V.G. Barabanov, I.G. Trukshin, Yu.I. BabenkoFSUE «Russian Scientific Center «Applied Chemistry», Dobrolubov ave., 14,St. Petersburg, 197198, Russia, E-mail: vg@astor.ruThe Montreal Protocol on Substances that Deplete the Ozone Layer (ODS) issued a newchallenge on the processes for non-ozone-depleting substituents (NODS) manufacture.In cooperation with other Russian institutions FSUE «Russian Scientific Center «AppliedChemistry» (RSC ACh) carried out a lot of work on changeover of industrial sector to suchnovel chemicals. This research resulted in a new family of hydrofluorocarbons producedunder Russian trademark «hladon»: HFCs 134а (CF 2 CFH 2 ), 152а (CF 2 HCH 3 ), 125(CF 3 CF 2 H), 32 (CH 2 F 2 ) etc.The applied method was that of gas-phase hydrofluorination catalyzed with chromiummagnesiumfluoride catalyst (CMFC).The major steps of the work were follows:1. Optimization of the supported catalyst composition.Our search for suitable CMFC formulations was accelerated considerably thanks to anewly developed computational method for forecasting of CMFC activity depending onactive component (АС) concentration on the catalyst surface. According to our calculationsCMFC activity hits its maximum when the support specific area is 95m 2 .g -1 and Cr (III)concentration is 9,4 %. Our tests confirmed both the calculation results and the applicabilityof the proposed mathematical model.2. Mathematic model for the process of gas-phase catalytic hydrofluorination.The kinetic principles of CMFC-catalyzed hydrofluorination of trichloroethylene and1,1,1-trifluorochloroethane in a continuously operated laboratory-scale plant were studied indetail. Our mathematical model represented the gross process through 21 stages. The relatedkinetic model described variations in both feedstock and intermediates concentrations underisothermal conditions. LSODA method was used for numerical integration of the ordinarydifferential equations system. The search for constant values was considered as the task ofregression analysis. The functional minimization was carried out using Gauss-Newtonmethod.Our tests confirmed the mathematical model adequacy.3. Design of industrial reactors.Starting with the obtained results we proposed the flow diagram for gas-phase synthesisof 1,1,2-tetrafluoroethane from trichloroethylene.The above industrial process optimization method proved to be also applicable inupdating of processes for other NODS synthesis.290