Info

0910 0915 0920 0925 0 930 0935 0 940 0945 0950 0955 0960 0965 0970 0975 0980 0985 0 990 0995 10 Mol fraction alcohol in liquid Fig. 8-15.

For the atmos-

0910 0915 0920 0925 0 930 0935 0 940 0945 0950 0955 0960 0965 0970 0975 0980 0985 0 990 0995 10 Mol fraction alcohol in liquid Fig. 8-15.

The low-pressure tower requires a still and 65 theoretical plates. The atmospheric pressure tower needs a still plus 120 theoretical plates. In view of the high heat consumption and the large number of plates required, other methods of producing absolute alcohol are more economical. Pressures above atmospheric would be advantageous for tower 2 and result in fewer theoretical plates.

Nomenclature

6', c' = constants in Margules equation D = distillate rate, mols per unit time O = overflow rate, mols per unit time P = vapor pressure

R « net molal withdrawal rate from section other than Vn and On+i S » steam rate, mols per unit time

T » temperature

V = vapor rate, mols per unit time W ™ bottoms rate, mols per unit time x « mol fraction in liquid y « mol fraction in vapor 7 « activity coefficient w = total pressure

References

1. Beebee, Coulter, Lindsay, and Baker, Ind. Eng. Chem., 34,1501 (1942).

2. " International Critical Tables," Vol. Ill, p. 322, McGraw-Hill Book Company, Inc., New York, 1928.

4. Lewis and Carey, Ind. Eng. Chem., 24, 882 (1932).

5 Sims, Sc.D. thesis in chemical engineering, M.I.T., 1933.

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