Calculating the space time for parallel reactions. m-Xylene is reacted over a ZSM-5 zeolit...

Calculating the space time for parallel reactions. m-Xylene is reacted over a ZSM-5 zeolite catalyst. The following parallel elementary reactions were found to occur in excess H2 [Ind. Eng. Chem. Res., 27, 942 (1988)] :

(a) Calculate the PFR volume to achieve 85% conversion of m-xylene in packed-bed reactor. Plot the overall selectivity and yields as a function of τ. The specific reaction rates are k1 = 0.22 s-1 and k2 = 0.71 s-1 at 673°C.

A mixture of 75% m-xylene and 25% inerts is fed to a tubular reactor at a volumetric flow rate of 200 dm3/s and a total concentration of 0.05 mol/clm3 As a first approximation, neglect any other reactions such as

the reverse reactions and isomerization to o-xylene.

(b) Suppose that E1 = 20,000 cal/mol and E2 = 10,000 cal/mol, what temperature would you recommend to maximize the formation of p-xylene in a 2000-clm3 CSTR