Get access

Solvent recovery targeting

Authors

  • Berit S. Ahmad,

    1. Dept. of Chemical Engineering and Energy Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139
    Current affiliation:
    1. Norsk Hydro ASP, P.O. Box 200, N-1321, Stabekk, Norway
    Search for more papers by this author
  • Paul I. Barton

    Corresponding author
    1. Dept. of Chemical Engineering and Energy Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139
    • Dept. of Chemical Engineering and Energy Laboratory, Massachusetts Institute of Technology, Cambridge, MA 02139
    Search for more papers by this author

Abstract

One of the environmental challenges faced by the pharmaceutical and specialty chemical industries is the widespread use of organic solvents. With a solvent-based chemistry, the solvent necessarily has to be separated from the product. Chemical species in waste-solvent streams typically form multicomponent azeotropic mixtures, and this often complicates separation and, hence, recovery of solvents. A design approach is presented whereby process modifications proposed by the engineer to reduce the formation of waste-solvent streams can be evaluated systematically. This approach, called solvent recovery targeting, exploits a recently developed algorithm for elucidating the separation alternatives achievable when applying batch distillation to homogeneous multicomponent mixtures. The approach places the composition of the waste-solvent mixture correctly in the relevant residue curve map and computes the maximum amount of pure material that can be recovered via batch distillation. Solvent recovery targeting is applied to two case studies derived from real industrial processes.

Get access to the full text of this article

Ancillary