Filtration of soot/ash water slurries and improved partial oxidation process for hydrocarbon feedstocks

US5628911A · kind A · utility

Assignee

• NORSK HYDRO ASA · NO

Inventors

• Wolfgang Kowallik · Itzehoe, DE
• Hans Jurgen Maaz · Brunsbüttel, DE
• Thomas Schmitz · Wesseling, DE

Key dates

• Filing date: Aug 4, 1995
• Grant date: May 13, 1997
• Expiry date: Aug 4, 2015

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/129
• WIPO field: Basic materials chemistry
• WIPO sector: Chemistry

Abstract

An improved partial oxidation, gasification process using low grade hydrocarbon feedstock involving the steps of gasification, waste heat recovery and carbon removal under formation of a soot water slurry containing the unburned carbon and ash. The soot water slurry is filtered to form a filtercake of carbon and ash, which cake is removed from the process. A direct once-through, partial oxidation process is thereby established, avoiding the recycle of unburned carbon and ash. The method also comprises filtration of the soot-ash slurries containing 0.5-3% unburned carbon and 0.1-2% ash having appreciable amounts of Fe, Ni and V. The slurry is cooled to a temperature below 80.degree. C. and filtered while confined between movable closed belts maintaining a constant pressure against the shrinking mass of carbon/ash particles until the moisture content is reduced to below 80% by weight. Flocculating agents are added to the soot slurry before filtration, one in the form of a cationic and the other in the form of an anionic flocculation agent. A flaky, or granular filtercake suitable for further processing is obtained.