Investigation of the selection of extraction solvent for extracting the n-alkane from diesel by means of solubility parameters theory

The solubility parameters (including dispersion coefficient δd, polarity δp, and hydrogen bonding δh) of extraction solvents (like ketones, chlorinated hydrocarbon, ester, alcohol, and ether) and diesel oil components (n-alkanes and aromatics) were estimated by using the group contribution method. The relationship between the solubility parameters of the solvent and the extraction efficiency of n-alkane from diesel oil was investigated. The results illustrated that the larger the difference between the solvent and n-alkane in the solubility parameters is, the higher is the extraction ratio, for the solvents except alcohols. Nonalkane content of waxpaste removed by the solvents with a dispersion contribution (fd) of higher than two-thirds was much less than that by the solvents with a lower fd.