Method for processing mixtures containing m-xylene and p-xylene, and with or without o-xylene and/or ethyl benzene

摘要

Meta-xylene is separated from a C8-aromatic mixture containing para-xylene by chlorinating while dispersed in anhydrous formic acid with chlorine or an aryliodide dichloride containing a -NO2, -CN or -COOH group at 5-30 DEG C. with stirring whereby the m-xylene is selectively chlorinated and separating the unreacted hydrocarbons. The m-xylene may be recovered by hydrogenation, e.g. in the presence of nickel on alumina or platinum on charcoal and may then be subjected to isomerization to form p-xylene. Ortho-xylene if present is separated by distillation before or after the m-xylene separation.ALSO:Monochloro-meta-xylene is obtained from a C8-aromatic mixture containing para-xylene by chlorinating while dispersed in anhydrous formic acid with chlorine or an aryliodide dichloride containing a -NO2, -CN or -COOH group at 5-30 DEG C. with stirring whereby the m-xylene is selectively chlorinated and separating the unreacted hydrocarbons. An example indicates that the product is a mixture of 2-chloro-and 4-chloro-m-xylene.