PATENT

2872. -----[RUHRCHEMIE, A.G.] [Catalysts for Aromatization or Dehydrogenation.] German Patent Appl. --, R 687, filed Aug.20, 1943 (Cl. IV d-23 b). FIAT Reel K-30, frames 7,896-7,902; PB 73,587; TOM Reel 36, bag 3,454, item 20, 7 pp; TOM Reel 37, bag 3,451, item 36.

In making catalysts for aromatization or dehydrogenation in accordance with German Patent Appl. R 114,653, use is made of Al hydroxide, which is quickly precipitated with acids under definite concentration and temperature conditions from Na or K aluminate solution and freed directly from its alkali content up to a definite limit by washing.  It is then calcined under strictly regulated duration and temperature producing a starchy product, which is plasticized with Cr nitrate containing definite amounts of H₂O and acid under addition of regulated amounts of alkali, shaped and then strongly calcined at a definite temperature after a slow heating to an initial temperature.  There may also be used a starchy Al hydrate, which has been aobtained by precipitating the hydroxide using CO₂ from an aluminate solution containing about 5% NaOH at about 25°-35°, whereby the Na is present in excess, preferably about 80%, above the amount represented by the formula NaAlO_2.