Additional Homework Problems

CDP12-DB

The hydrogenation of 2-butyne-1,4-diol to butenediol is to be carried out in a slurry reactor using a palladium-based catalyst. The reaction is first-order in hydrogen and in diol. The initial concentration of diol is 2.5 kmol/m3. Pure hydrogen is bubbled through the reactor at a pressure of 35 atm at 35°C. The equilibrium hydrogen solubility at these conditions is 0.01 kmol/m3, and the specific reaction rate is 0.048 m6/kgkmols. The catalyst charge is 0.1 kg/m3 with a particle size of 0.01 cm and pellet density of 1500 kg/m3.

  1. Calculate the percent of the overall resistance contributed by each of the transport steps.

  2. Plot conversion as a function of time up to 95%.

  3. How could the reaction time be reduced?

Additional Information:

diffusivity = 10-9 m2/s for H2 in organics

kbab = 0.3s-1

kc = 0.005 cm/s for H2 in organics

kc = 0.009 cm/s for 2-butyne-1,4-diol in butenediol

pellet density = 1.6 g/cm3 pellet porosity = 0.45

[3rd Ed. P12-21]