Chemical Reaction Engineering GATE-2018
Q 1: Liquid phase isomerization of o-xylene to p-xylene using a zeolite catalyst was carried out in a CSTR. Three sets of kinetic data at different temperatures and stirring speeds were obtained as shown below.
| Set A | Set B | Set C | |||||||
| Temperature (K) | 500 | 500 | 500 | 600 | 600 | 600 | 700 | 700 | 700 |
| Stirring speed (rpm) | 1000 | 2000 | 3000 | 1000 | 2000 | 3000 | 1000 | 2000 | 3000 |
| Reaction rate (mol L-1 s-1) | 0.020 | 0.025 | 0.025 | 0.037 | 0.047 | 0.047 | 0.069 | 0.078 | 0.086 |
The operating condition at which the reaction rate is not controlled by external mass transfer resistance is
Q 2: For a chemical reaction, the ratio of the rate constant at 500 K to that at 400 K is 2.5. Given R = 8.314 J mol-1 K-1, the value of activation energy (in kJ/mol) is
Q 3: In a laboratory batch setup, the reaction of P over a catalyst was studied at various temperatures. The reactions occurring are P\rightarrow2Q;\;\;P\rightarrow R . At the end of one hour of operation, the batch contains xP, xQ, and xR mole fractions of P, Q, and R components, respectively. The mole fractions of product components (xQ and xR) were found to vary linearly with temperature as given in the figure.
If the yield of Q based on reactant P consumer (YQ) at 25 ˚C was found to be 0.40, then the value of YQ at 60 ˚C is ________ (rounded off to the second decimal place.)
Q 4: A CSTR and a PFR of equal volume are connected in series as shown below to carry out a first-order, isothermal, liquid phase reaction ( A\rightarrow P )
The rate constant is 0.2 s-1. The space-time is 5 s for both reactors. The overall fractional conversion of A is ______ (rounded off to the third decimal place).
Q 5: The elementary second-order liquid phase reaction A+B\rightarrow C+D is carried out in an isothermal plug flow reactor of 2 m3 volume. The inlet volumetric flow rate is 10 m3/h. The initial concentrations of both A and B are 2 kmol/m3. The rate constant is given as 2.5 m3 kmol-1 h-1. The percentage conversion of A is _____________.
Q 6: Hydrogenation of benzene is to be carried out using Ni (density = 8910 kg/m3) as a catalyst, cast in the form of non-porous hollow cylinders, as shown below.
The reaction occurs on all the surfaces of the hollow cylinder. During an experiment, one such cylinder is suspended in the reactant stream. If the observed rate of reaction is 0.39 mol (m2 of catalyst surface)-1 min-1, then the rate of reaction in mol (kg of catalyst)-1 min-1 is _______ (rounded off to three decimal places).