Shortcut applications of the Hansen Solubility Parameter for Organic Solvent Nanofiltration

In this paper the representation of the Hansen Solubility Parameter (HSP) in a ternary diagram is explored in order to define new applications for it in the field of Organic Solvent Nanofiltration (OSN). The use of the HSP is extended to the qualitative prediction of the behaviour of solvents or solutes in OSN as well as to estimate the HSP of ceramic membranes. This is done by representing the three components of the HSP as the axes of the ternary diagram and observing the relative positions of the HSP of solvents and solutes. In general, the closer two points are in the diagram, the larger the interactions. In membrane processes a larger solvent-membrane interaction is linked to a higher flux through the membrane; thus, plotting the flux of pure solvents through a given membrane and grouping these data by flux is postulated to give an estimation of the HSP distribution of the membrane. As a result, knowing the HSP of every component in a membrane filtration system is the first step into developing an affinity driven model for OSN with the HSP as the main parameter to describe the internal interactions not only of the solvent but also of the solute and the membrane. This is demonstrated for non-swelling ceramic membranes, for different solvents and solutes, which are scattered in the HSP diagram. It was concluded that the trend of the fluxes, ranging between 47 and 300 l h−1 m−2, and rejection (−5% to −85%) match well with their position in the diagram, which opens the possibility to a more quantitative prediction of performance, and to specifically design applications based on a given membrane.