25 428 10 4 01 1057 for montz ah a 0850482563

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Unformatted text preview: ite small. mV (c) From Eq. (7.52), HOG = HG + H L , where we must use the slope, m, of the equilibrium L curve instead of a K-value because the equilibrium curve is curved. At the top of the column: Near a mole fraction, xD , of 0.9, m = (0.9780 - 0.9359)/0.10 = 0.42 Estimate HL from Eq. (6-132), using the following properties and parameters: NOR PAC Montz CL 1.080 1.165 3 3 hL , m /m 0.0162 0.0241 0.947 0.930 , m3/m3 uL, ft/s 0.00898 0.00591 2 3 a, m /m 86.8 300 ah, m2/m3 52.9 93 1/ 3 Analysis: (c) at the top of the column (continued) Exercise 7.52 (continued) Need an estimate of the diffusivity of methanol in water at high concentrations of methanol. From Example 3.7, the diffusivity of methanol in water at a mole fraction of 0.8 and 25oC is 1.5 x 10-5 cm2/s. Use Eq. (3-39) to correct this for temperature to 170oF or 350 K and viscosity. For methanol, viscosity at 25oC (298 K) = 0.55 cP and at 350 K, viscosity = 0.32 cP. Therefore, 350 0.55 DMeOH = 150 10-5 . = 3.0 10-5 cm2/s 298 0.32 From Eq. (6-132), for NOR PACK, using SI (i...
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This note was uploaded on 09/08/2008 for the course CHE 244 taught by Professor Selebi during the Spring '06 term at Lehigh University .

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