Improvements in the process for the manufacture of high-percentage and pure solid hydrocarbons from tars

摘要

In distilling tars, as described in the parent Specification, the fractions which contain solid ingredients are cooled to obtain these ingredients as crystals which are separated by draining or by centrifugal means. The separated solids are again distilled and the vapours passed through a fractionating column, the reflux from which passes back to the still. The vapours passing from the top of the column are collected in narrow fractions. In this way, naphthalene, acenaphthene, fluorene, diphenylene oxide, phenanthrene, anthracene, fluoranthrene and pyrene may be obtained. The distillation may be carried out under ordinary or reduced pressure.