Recovery of Phosphoric Acid from Spent Petrochemical Catalysts |
| |
Authors: | Valentin G Greb Martin Bertau Axel Düker Andreas Geisbauer Peter Fröhlich |
| |
Affiliation: | 1. TU Bergakademie Freiberg, Institute of Chemical Technology, Leipziger Straße 29, 09599 Freiberg, Germany;2. Clariant Produkte (Deutschland) GmbH, Lenbachplatz 6, 80333 München, Germany |
| |
Abstract: | Petrochemical catalysts are widely used in the industry. For the production of cumene, zeolite-based catalysts containing phosphoric acid are applied. Over the time, coking deactivates the surface, and the catalyst has to be exchanged and disposed of. Different process approaches for recycling the phosphoric acid-containing catalysts were investigated. Related preliminary investigations have shown that calcination of the used catalyst is necessary prior to reprocessing. By digesting the catalyst with hydrofluoric acid, ~96 % phosphate was recovered. However, this process is very costly in terms of process technology. More promising is digestion by basic or acidic routes. Several options are possible here, and digestion with H3PO4 proved to be particularly suitable. Here, phosphate yields reached up to 98.8 %, with a positive balance of economic efficiency at the same time. The catalyst can be produced and recycled in the same plant with the same reagents, what constitutes a major breakthrough towards sustainability in industrial catalysis. |
| |
Keywords: | Catalysis Phosphoric acid Wet chemical leaching |
|
|