Since solvents typically account for 80% of raw materials in pharmaceutical processes, efficient solvent usage is important to reduce the environmental footprint of the pharmaceutical industry. This talk will present several ways in which conceptual design can be used to optimize solvent usage during common pharmaceutical operations requiring batch distillation.

We will outline a general method to use UNIFAC models for predicting separation efficiency as a function of pressure, solvent charge method, and entrainers. These predictions can then be used to choose distillation conditions which minimize solvent usage. We will show several case studies of how conceptual design has been successfully applied at pilot plant scale of pharmaceutical processes.