Kinetics For Electrochemical Dechlorination Of Polychlorinated Biphenyls In Continuous Stirred Tank Reactor And Plug Flow Reactor

Kinetics model was very important for the design and optimization of a certain reactor.In this study,electrocatalytic hydrodechlorination of 4,4'-dichlorobiphenyl(4,4'-DCBP)and 2-chlorobiphenyl(2-ClBP)at a palladium-modified nickel foam cathode(Pd/Ni foam)were performed in a continuous stirred tank reactor(CSTR)and a plug flow reactor(PFR)to describe and predict the dechlorination efficiencies of parent reactants and yield of intermediates.As a result,it was found that the dechlorination process follows pseudo-first-order kinetics,and two mathematical models were established based on the pseudo-first-order reaction rate constants obtained under various initial concentrations of parent reactants(C0),Pd loadings(M),current densities(J)and temperatures(T).In CSTR,the dechlorination efficiencies expression of 4,4'-DCBP(Xmod1),with Arrhenius dependency,was determined to be Xmod1=4256/[1/(C4,4'-DCBP,0 0.0103 M1.1008 J0.8163exp(-35506/RT)?)+4256]While the yield of 4-CIBP(Xmod2)can be expressed as Xmod2=4256/[l/(C4,4'-DCBP,0 0.0103 M1.1008 J0.8163 exp(-35506/RT)?)+4256]/[1+3935C4,4'-DCBP,0 0.0249 M1.3493 J0.8443 exp(-30316/RT?)In PFR,the predicting model of 2-ClBP(Xmod)was Xmod=1-exp[-1.0982?106C-CIBP,0 0.0141 M0.9307 J1.3461 exp(-34615/RT)?]Subsequently,a series of additional experiments in a wider range of operating conditions were performed to verify the accuracy of the models above.It was found that the model values are in good agreement with experimental values,with the deviation of<15.3%in CSTR,and<8.9%in PFR.These deviations were acceptable,considering the high complexity of the reaction system.