PURPOSE: To provide a process whereby p-dichlorobenzene can be separated from a mixture with m-dichlorobenzene at a very high selectivity at only one elution step.
CONSTITUTION: A mixture of m- and p-dichlorobenzene is separated by treating the mixture with zeolite in the presence of a solvent combination. The solvent combination comprises at least two different solvents selected from two groups, respectively, one group comprising compds. of formula I (wherein Hal is Cl or Br; R1 is Hal or 1-4C alkyl; and R2 is R1 or H provided R1 and R2 may combine with each other to form an indan, tetralin, or naphthalene residue) excluding 4-chlorotoluene and dichlorobenzene and the other group comprising compds. of formula II (wherein R3 is 1-4C alkyl, 1-4C alkoxy, 1-4C alkylcarbonyl, or the like). The zeolite used is a pentasil zeolite contg. protons and cations of the first or second main group or of rare earth metals as exchangeable cations. A filtrate enriched with m-dichlorobenzene is taken off, and p- dichlorobenzene is recovered by the extraction from the zeolite.
HANSUUYOZEFU BUISHIYU
ROTAA PUTSUPE
MIHIYAERU PIISU
HANSUUINGORUFU PAURU
