Question:
An unsaturated organic (A) dissolved in a solvent is being hydrogenated by bubbling pure hydrogen through the liquid to form a product (B) in the reaction, A + H2 ?
B. The column is 10 cm in diameter and 2 meters high, and the bubbles may be assumed to rise at a constant velocity of 10 cm/s. The bubbles enter the bottom of the reactor with a diameter of 0.05 cm at a pressure of 125 kPa and exit at a pressure of 101 kPa.
The temperature is constant at 300 K. Hydrogen is transferred to the liquid with a rate limited by mass transfer (km = DH2/r) in the liquid around the bubble with DH2 = 10?5 cm2/s. There is no reaction in the bubbles. The liquid phase in the reactor may be modeled as ideally mixed. At steady-state, the concentration of hydrogen in the liquid is 1 mmol/L.
Calculate the diameter of the bubbles at the top of the reactor assuming that no coalescence occurs.