*Answers to problems with an asterisk are at the back of the book.
D1.* A gas permeation system with a cellulose acetate membrane will be used to purify a carbon dioxide-methane stream. The permeabilities are given in Example 17-2. The effective membrane thickness tms = 1.0 μm (a micron = 1.0 × 10−6 meter). Operation is at 35°C. pH = 12 atm and pL = 0.2 atm (a vacuum). The feed is 15 mol% carbon dioxide. Assume ideal gases.
a. *A single-stage, well-mixed membrane separator will be used. Operate with a cut, θ = Fp/Fin = 0.32. Find yp, yout, and flux of carbon dioxide. If we feed 1 kmol/h of feed, calculate the membrane area needed, Fp and Fout.
b. Design the two-step gas permeation system shown in the figure on the following page. ...