Bachelor Assignments

Separation of benzoic acids by extractive distillation

BSc-project description

Coach: Lisette Sprakel

Separation of benzoic acids by extractive distillation

Separation of carboxylic acids can be performed by distillation and/or extractive distillation. Especially in the case of similar boiling points, the process of extractive distillation is a promising alternative because of the increase of relative volatility. Two acids with similar boiling points are benzoic acid and o-toluic acid. These acids have similar boiling points but there is a difference in pKa value of 0.3.

This BSc project focuses on the separation of benzoic acid and o-toluic acid by extractive distillation. Previous work on separation of two other acids with similar boiling point showed that a difference in pKa enables separation with a basic solvent in extractive distillation.

This project will result in more understanding of affinities, optimal binding strengths and affinity agent regeneration. An important point of interest is the optimal binding strength concerning both extraction and regeneration of the solvent and the possibility of scaling the solvents.

The main elements of this BSc project are:

  1. Literature study on extractive distillation of organic acids and separation of benzoic acids.
  2. Obtain binary VLE data for the benzoic acid mixtures, using an ebulliometer.
  3. Use for example trioctylamine as a solvent and obtain ternary VLE data for the benzoic acid system when an additional solvent is used
  4. Investigate the recovery of the solvent. Determine binary VLE data of one of the benzoic acids with the solvent.