Question 1 An ammonia synthesis catalyst fixed bed consists of monodisperse (single-size) spherical particles 1 mm in radius. The effective diffusivity of nitrogen in the particles is De = 10-?m/s. The feed partial pressures are 1 bar N2 and 3 bar H2. The conversion is very low in the reactor, so that N2 concentration can be assumed constant outside the particles. The reactor temperature is 600 K. At this temperature the nitrogen turnover frequency on the metal catalyst surface is 0.05 molecules/site--s-1. The catalyst particles have a density 7 g/cm and contain a metal surface area 30 m/g. The reaction is first order with respect to nitrogen. Each surface metal atom occupies 10.0 2 surface area. (a) Calculate the Thiele modulus Os. (b) Calculate the effectiveness factor n. (c) Calculate he reaction rate of nitrogen per unit volume of reactor R (mol Nz/ms) if the bed packing density is fp = 0.6. (d) A microreactor 10 mm in radius is loaded with 10 g of catalyst particles. Determine the range of inlet total flowrate required (mol/s) for a stoichiometric Nz/H2 mixture at 4 bar total pressure, if the nitrogen conversion at the outlet should be less than 0.02. (e) The effective diffusivity can be assumed to be given by De = D. 9T15 where I is the temperature in K. The activation energy for the reaction is 65 kJ/mol in the temperature range 450 750 K. Make an Arrhenius plot In(R), where R is the rate per volume of reactor, versus 1/T for this temperature range and comment on the apparent activation energies that would be extracted from this plot