Patent GB-583812-A (GB)
Title: Improvements in and relating to the refining of benzole
IPC: C07C7/14
Filed: 1943-07-29
Abstract: Crude benzole i.e., a fraction boiling at approximately 75-95 DEG C. whose aromatic content is mainly benzene, is cooled to between 0 and -100 DEG C., the solid product which is mainly benzene with possibly some cyclohexane is washed within this temperature range with a paraffinic, cycloparaffinic, or olefinic hydrocarbon of from 2 to 5 carbon atoms which is liquid at the washing temperature and has a boiling point sufficiently different from benzene to permit recovery by distillation, whereby constituents which have not solidified and cyclohexane are dissolved, leaving substantially pure benzene.  The benzole may be obtained by carbonization of coal, thermal or catalytic cracking or treatment of oils such as mineral, coal or shale oils or hydrogenation of coal and coal tar.  Suitable washing hydrocarbons are propane, isopentane, cyclopentane, propylene or mixtures of propylene and propane.  They may be added to the benzole before cooling to separate the solid or to the separated solid. After separation of the solvent from the dissolved hydrocarbons, the latter may be used as a motor fuel.  In an example, a crude benzole containing 65 per cent. aromatics, obtained by hydrogenation of coal tar, is cooled to 60 DEG C. and the filter cake washed, three times, each with one third its volume of propane.  The wash liquid, after separating solvent, is again treated.  Nitration benzene, and a by-product motor fuel are obtained.  Specification 479,957 is referred to.  The Provisional Specification refers to the use as washing liquid of a non-aromatic hydrocarbon preferably containing from 1 to 7 carbon atoms.ALSO:Crude benzole, i.e. a fraction boiling at approximately 75-95 DEG  C. whose aromatic content is mainly benzene, is cooled to between 0 DEG  and -100 DEG  C., the solid product which is mainly benzene with possibly some cyclohexane is washed within this temperature range with a paraffinic, cycloparaffinic, or olefinic hydrocarbon of from 2 to 5 carbon atoms which is liquid at the washing temperature and has a boiling point sufficiently different from benzene to permit recovery by distillation, whereby constituents which have not solidified and cyclohexane are dissolved, leaving substantially pure benzene.  The benzole may be obtained by carbonisation of coal, thermal or catalytic cracking or treatment of oils such as mineral, coal or shale oils or hydrogenation of coal and coal tar.  Suitable washing hydrocarbons are propane, isopentane, cyclopentane, propylene or mixtures of propylene and propane.  They may be added to the benzole before cooling to separate the solid or to the separated solid. After separation of the solvent from the dissolved hydrocarbons, the latter may be used as a motor fuel.  In an example, a crude benzole containing 65 per cent aromatics, obtained by hydrogenation of coal tar, is cooled to -60 DEG  C. and the filter cake washed, three times, each with one-third its volume of propane.  The wash liquid, after separating solvent, is again treated.  Nitration benzene and a by-product motor fuel are obtained.  Specification 479,957, [Group III], is referred to.  The Provisional Specification refers to the use as washing liquid of a non-aromatic hydrocarbon, preferably containing from 1 to 7 carbon atoms.