5. Williams proposed a Sherwood type correlation for the mass transfer coefficient in packed bed reactors as: Sh=2+0.6(Re)0.45(Sc)0.33 where Sh=DhDdp,Re=vudp,Sc=Dv,hD is the mass transfer coefficient, D the diffusion coefficient (m2s1),dp the diameter of the catalyst particle (m),u the fluid velocity (ms1) and v the kinematic viscosity (m2s1). A catalyst bed contains spherical particles of 2cm diameter suspended in a large body of fluid. The reactant is present in dilute concentration and the reaction is considered to take place instantly at the external surface of the catalyst. The bulk concentration of the reactant is 1.6M and the liquid velocity is 0.5ms1. The kinematic viscosity is 0.65106m2s1 and the diffusion coefficient of the reactant is 11010m2s1. UESTION 5 CONTINUES ON THE NEXT PAGE TURN OVER PAGE 4 of 9 UESTION 5 CONTINUES (a) Assuming the Williams correlation is valid, calculate the expected magnitude of the external mass transfer limitation coefficient stating units. [3 marks] (b) Determine the mass flux of reactant A stating units. [3 marks] (c) Determine the reaction rate of the catalysed chemical reaction, expressing your units as rate per catalyst particle (mols [catalyst particle] ]1s1 ). [4 marks] (d) The intention of the company is to scale up this process to a fluidised bed reactor. Why would the company wish to do this and would this be a viable option? Justify your