Oligomer fractionation with supercritical fluids

A technical comparison of supercritical fluid fractionation and short path distillation for the processing of oligomers is presented. Through experiments and models it is shown that a supercritical fluid fractionation column can produce much sharper cuts than a single short path distillation unit. At comparable conditions the supercritical fluids ethane and CO2 gives virtually the same separation factors for alkane mixtures. The advantage of using ethane is the much lower pressures that would be required. Unlike short path distillation, supercritical fluid processing caused no discoloration of the bottoms products.