Effect of solvents for the production of cyclopentane by extractive distillation

In view of the rapid phasing out of fluorocarbons due to their adverse ozone-depleting potential, alternative environment-friendly chemicals are being explored for blowing polyurethane, the key insulation material in refrigeration industries. Cyclopentane with required physical and thermal conductivity properties has emerged as the most appropriate alternative as it can be acquired from light petroleum hydrocarbons, which are abundant. Light naphtha is a mixture of several closely boiling hydrocarbons and hence even a narrow fractional distillation may not enrich cyclopentane for required purity and instead it results only in an azeotropic mixture. This article describes the work carried out in obtaining commercially pure cyclopentane from light naphtha through an extraction-distillation combined operation which is commonly termed as "extractive distillation." The solvent type and key operating parameters, namely, feed naphtha cut range (heart cut), solvent/feed ratio were studied and the results obtained were further correlated with simulated model prediction.