Abstract
Resulting from the trend of increasingly stringent
environmental legislation, the drive to secure environmentally
friendly absorption solvents has gained much impetus in recent
times. In order to design and operate separation processes units, it
is essential that the engineer has accurate and reliable knowledge
of the phase equilibrium behaviour of the system in question. Since
obtaining experimental data on the system can be time-consuming,
the use of thermodynamic models is often useful in obtaining
preliminary design and feasibility study information. This work
examines the suitability of biodiesel (particularly the constituents
methyl palmitate and methyl linolenate) as an absorbent solvent for
the recovery of volatile organic compounds (VOCs) from waste
process gas streams. In particular, activity coefficients were
measured in the dilute region in an attempt to predict the effects of
molecular structure and temperature on the solubility of the VOCs
in the methyl esters under study. The group contribution methods
UNIFAC and Modified UNIFAC Dortmund, set up on Microsoft
Excel spreadsheets, were used to predict the required phase
equilibrium at infinite dilution. The results obtaine