As part of a biorefining effort, butanediols are being produced by fermentation. The problem is that the isomers are all mixed up. Furthermore, 1,3-propanediol comprises roughly 30mol% of the mixture on a dry basis (i.e., water has been removed). The problem is to assess the prospects for azeotrope formation and avoidance. The following steps should shed some light on the problem.

(a) Plot log₁₀(P^sat) versus 1000/T(K) in the range of T°C = [100,400] for 1,3-propanediol, 1,3-butanediol, and 1,4-butanediol on the same axes. Are there Bancroft points?

(b) Compile a table of γ^∞_i for each component in each solvent based on the SSCED model. Which combinations show the greatest tendency to form azeotropes?