6. Moving bed is used in catalytic reactors continuously to remove and replace spent catalyst. One example is to produce xylene from toluene disproportionation. The below elementary reaction was studied over a specific catalyst, which follows second-order decay by sintering (ka = 1.6 h-). (20 marks) specific reaction rate constant k = 1000 L(kg cat*mol*h) a) What conversion can be achieved if the rector containing 50 kg catalyst with a feed rate of 3 kg/h. Toluene is fed at 0.5 mol/L and a rate of 400 mol/h. 2 Toluene Benzene + Xylene 2T B+X b) Choose and explain the flow mode of catalyst, co-current or counter-current, for the below situations, respectively. 1). An exothermic reaction with wall cooling where it is important to minimize and spread out the hot spot to avoid thermal deactivation. 2). A situation where the feed contains catalyst poisons that deactivate the catalyst by absorbing on it and where the strategy is to maintain activity throughout the bed.