Process for preparing debenzolized tar and low-benzene centrifuged tar sludge
AssigneeAristech Chemical Corporation
InventorsJohn Stipanovich, Jr., David Q. Wible
Life of this patent
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Abstract
Crude coal tar is distilled in the form produced in a coke plant. The distillation tower contains a rectification section to retain naphthalene with the other components heavier than benzene. The benzene is removed overhead.
Claims6
Method of making a coal tar having less than about 100 ppm of benzene comprising (a) distilling said tar, said distillation characterized by (i) retaining naphthalenes in the tar, (ii) refluxing the light components thereof, (iii) reboiling the heavier components thereof, and (iv) removing benzene therefrom, and (b) recovering a tar having a benzene content less than about 100 ppm.
Method of making a substantially debenzolated coal tar and a low benzene fuel tar comprising distilling a coal tar containing at least about 0.1 wt. % benzene to remove benzene therefrom and obtain a debenzolated coal tar having no more than about 100 ppm benzene, passing said debenzolated coal tar to a centrifuge, centrifuging said debenzolated coal tar to separate said debenzolated coal tar into a clear friction relatively free of coal particles and a sludge containing at least 60% of the coal and coke particles in said debenzolated coal tar, and recovering a debenzolated sludge, useful as a fuel, containing no more than 100 ppm benzene and no less than about 30 wt. % of material insoluble in quinoline.
Dependencies are inferred from the claim text.