Description

Following is a sample of the information contained on this CD: CROSS-REFERENCE TO RELATED APPLICATION This application relates to German Application DE 109 44 325.0, filed Sep. 28, 1998, which disclosure is incorporated herein by reference. FIELD OF THE INVENTION The invention relates to a method of producing alcohols by catalytic hydrogenation of aldehydes or ketones using an Ru carrier catalyst. The catalyst to be used in accordance with the invention is deactivated to a rather slight extent and therefore has a higher service life than Ru carrier catalysts previously used for this purpose. BACKGROUND OF THE INVENTION The conversion of aldehydes and ketones into the corresponding alcohols by catalytic hydrogenation is known. Nickel carrier catalysts or Raney nickel are frequently used as catalysts for the hydrogenation of aldehydes and ketones. A disadvantage of such catalysts is the Ni leaching, during which Ni passes in dissolved form into the liquid reaction medium. This renders the workup of the reaction mixture difficult and the leached-out Ni must be removed, e.g., burned, with other byproducts, leaving carcinogenic NiO. In order to avoid the problems cited, carrier-bound noble-metal catalysts, especially Ru catalysts, have been used. B. J. Arena (Applied Catalysis A 87 (1992) 219-229) teaches the use of Ru catalysts on aluminum oxide for the hydrogenation of glucose to sorbitol. A disadvantage of this catalyst is the short effective service life caused by deactivation. During the deactivation of Ru--Al.sub.2 O.sub.3 not only deactivating components such as iron, sulfur and gluconic acid are deposited on the catalyst but at the same time the properties of the Ru carrier and of the Al.sub.2 O.sub.3 carrier change, which manifest themselves in, among other things, an agglomeration of the Ru and a reduction of the BET surface of the Al.sub.2 O.sub.3. In order to reduce the deactivation, additional purification measures of the feed