Determination of the Henry's constant and the mass transfer rate of VOCs in solvents

Absorption of hydrophobic volatile organic compounds (VOCs): dimethylsulfide (DMS), dimethyldisulfide (DMDS) and toluene, in organic solvents: di-(2-ethyl)hexyladipate (DEHA), n-hexadecane, oleyl alcohol and PEG 400, was studied. In order to characterise the absorption capacity of various VOC/solvent systems, the Henry's constant (H) was determined. DMS was found to be the least absorbable in all the selected solvents. Amongst these solvents, DEHA was found to be the most efficient to absorb the considered VOCs. The effect of water addition to the considered solvents (emulsions) on the Henry's constants was examined and confirmed a decreasing VOC absorption for an increasing amount of water in solvent. Finally, to quantify the process rapidity, the absorption rate (N) and the overall liquid mass transfer coefficient (KLa) were measured for some selected couples VOC/solvent and revealed a superior efficiency of DEHA compared to other solvents in trapping DMS, DMDS and toluene.