Process for producing pitch raw materials

US4806228A · kind A · utility

Assignee

• Rutgerswerke Aktiengesellschaft · DE

Inventors

• Herbert Beneke · Castrop-Rauxel, DE
• Siegfried Peter · Erlangen, DE

Key dates

• Filing date: Jan 7, 1987
• Grant date: Feb 21, 1989
• Expiry date: Jan 7, 2007

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D11/0203
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for the production of pitch raw materials having improved properties comprising extracting coal-tar pitch free of solids with a mixture of a supercritical gas extracting agent and an entrainer at elevated temperatures and pressures, passing the extraction mixture to a plurality of separation steps where the supercritical gas and entrainer are removed by lowering the pressure and/or raising the temperature, recycling the mixture of extracting agent and entrainer to the extraction step and recovering the pitch fractions from the separation step, the said pitch fractions being useful for diverse purposes such as soot production, electrode bonding agents, etc.