The reaction is carried CH2O ⇔ CO + H2 is carried out in a 0.5 dm3 membrane reactor of 0.1 m diameter at 298 K (for which the rate constant is 1/min) and 15 psi at a flow of 10 mol/min. The feed is pure formaldehyde. The membrane only permits hydrogen to pass through it and has a diffusivity of 5x10-5 m2/s.
(a) Plot the conversion and species flow rates against the axial distance along the reactor. (b) Redo the analysis assuming the membrane is removed and the reactor operates as a simple PFR. (c) Determine the size of PFR necessary to achieve the same conversion as found in (a).
Sixty percent carbon dioxide (CO2) in a flue gas is to be removed by bubbling through a solution of sodium hydroxide (NaOH). The reaction is mass-transfer limited.
Calculate the reactor size (length and diameter) necessary to remove 99.9% of the carbon dioxide. The flow rate of the flue gas is 0.05 m3/sec and the flow rate of the sodium hydroxide is 0.001 m3/sec. The reactor must operate in the bubbly flow regime, so be sure to recommend a type of sparger to use.