Basf Aktiengesellschaft

Friedbert Hofmann

Matthias Schwarzmann

Richard Krabetz

Robert Heinz

Volker Buehler

Ascorbic acid granules for direct tableting are prepared by the compacting method, wherein the ascorbic acid in the form of crystals or crystal fragments, of which not more than 40% by weight have a longest particle diameter of less than 50 .mu.m and not more than 15% by weight have a longest particle diameter greater than 500 .mu.m, and as a mixture with from 0.8 to 8% by weight of soluble polyvinylpyrrolidone having a water content of from 0.3 to 5% is compacted in a conventional manner, and the product is comminuted.

Preparation of ascorbic acid granules

A molded catalyst for reactions carried out under heterogeneous catalysis consists of a catalytically active material shaped into hollow cylinders, or of an inert carrier which is shaped into hollow cylinders and onto which catalytically active material is applied the external diameter of the hollow cylinders being from 3 to 20 mm, the internal diameter being from 0.1 to 0.7 times the external diameter and the length being from 0.2 times to twice the external diameter. The end faces of the hollow cylinder are curved so that the radius of curvature is from 0.4 to 5 times the external diameter. The novel catalysts are particularly useful for partial oxidation in the gas phase.

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Neuhofen, Germany

Friedbert Hofmann