The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 02, 1989
Filed:
Mar. 13, 1987
Applicant:
Inventors:
Siegfried Peter, Uttenreuth-Weiher, DE;
Marc Seekamp, Erlangen, DE;
Herbert Beneke, Castrop-Rauxel, DE;
Jurgen Stadelhofer, Bad Soden, DE;
Assignee:
Rutgerwerke Aktiengesellschaft, Frankfurt am Main, DE;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
C07C / ; C07C / ;
U.S. Cl.
CPC ...
568761 ; 568749 ;
Abstract
Coal tar oil is separated quantitatively into neutral oil, phenols and bases by a two stage extraction with overcritical gases. Carbon dioxide is employed as an overcritical extraction agent, and propane or butane are preferably added as entrainers. The neutral oil is obtained in the first stage. Tar bases can be employed as an additional entrainer for improving the selectivity. The bases are extracted in the second stage. The method is associated with the advantage that it saves energy and that no byproducts are generated.