OP-II-3

PP-II-15THE WAYS OF RISE THE PRODUCTIVITY OF ETHYLENEOXYCHLORINATION REACTORSFlid M.Scientific Research Engineering Centre “Syntez”, Moscow, Russia.E-mail: mflid@yandex.ruThe main trend in the activities of leading producers of vinyl chloride is theintensification of existing manufactures that would increase the productmanufacturing in 1,5-2 times by increasing the unit capacity of reactor units.The main problem of the rise in the productivity of industrial reactors of ethyleneoxidative chlorination (oxychlorination) is the lack of balance between the kineticproductivity of catalysts and heat removal. A high value of heat of ethyleneoxychlorination (238 kJ/mol) necessitates the use of an array of fixed-bed catalyticreactors where each reactor contains catalysts with different compositions andactivities. The process temperature is 280–300°C. The processes of ethyleneoxychlorination in the fluidized bed of the catalyst (usually the systemsCuCl 2 /-γ Al 2 O 3 ) require lower (210–230°C) temperatures.Heat is removed by evaporating 10–15% of the boiling water in the cooling coilsimmersed in the catalyst bed.The productivity of low-temperature catalysts that provide at least 99%conversion of HCl is 1100–1400 g/(l Cat h). The real amount of the catalyst chargedinto the industrial reactor is 3–3.5 times greater than the minimum amount. This isusually associated with the impossibility of placing cooling devices in the limitedvolume of the catalyst bed. The intensification of heat removal and an increase in thereactor productivity is possible only if the temperature gradient Δt between thecoolant and the catalyst bed is increased.When low temperature catalysts are used, Δt is 40–45°C. An increase in thetemperature of the process to 235–240°C leads to a decrease in the selectivity of theprocess and formation of chloroorganic by-products and the products of deepoxidation (CO and CO 2 ).Paradoxically, the productivity of industrial fluidized-bed catalytic reactors can beincreased by using catalysts with a lower activity. A decrease in the activity ofalumina-based catalysts is usually achieved by adding alkali or alkali earth metal(Me) chlorides, most frequently K and Mg. These additives in an atomic ratio Me/Cu358