PART C.

The catalytic isomerization of n-butane to isobutane is carried out in an industrial packed bed reactor with solid catalyst particles at 460C and 3 bar with an initial n-butane concentration of 49.2molm3. Pure n-butane with a molar feed of 5000molh1n-butane is fed to the reactor and the rate law is given by: rnbutane=0.2Cnbutane2 Where rnbutane units is molkg1h1 Cnbutane unit is mol m3 a. Calculate the amount of catalyst ( kg ) needed if the amount of n-butane at the outlet of the reactor is 30molm3. Show your full working. Assume isothermal and isobaric operation with no external or internal mass transfer effect. [7 marks] b. Independent from question 2(a), it was decided to use 1000kg of catalyst. The catalyst deactivates by sintering (second order decay). The value of the decay constant at 460C is known to be 3 day 1. Calculate how many days this catalyst can be used, if the highest accepted amount of n-butane at the outlet of the reactor is 30molm3. Show your full working. Assume isothermal and isobaric operation with no external or internal mass transfer effect. [10 marks] c. Independent from question 2(a) and 2(b), assume isothermal operation, with no external or internal mass transfer effect and no catalyst deactivation. Calculate the amount of catalyst (kg) needed if the amount of n-butane at the outlet of the reactor is 30molm3 and the effect of pressure drop is taken into account with a pressure drop parameter =0.0085kg1. Show your full working