Process for reactivating silver catalysts used in the manufacture of ethylene oxide by direct oxidation
AssigneeHoechst Aktiengesellschaft
InventorsSiegfried Rebsdat, Sigmund Mayer, Josef Alfranseder
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Abstract
The efficiency of silver carrier catalysts having reduced activity for the manufacture of ethylene oxide by reacting ethylene with oxygen or air is improved by impregnating the used catalyst with a solution containing cesium and/or rubidium compounds, an aliphatic alcohol and at most 10% by weight of water. After impregnation the alcohol and optionally the water are evaporated. The cesium and/or rubidium content of the impregnating solution and the number of impregnations are adjusted to obtain on the carrier a cesium and/or rubidium concentration of from 1 to 1,000 ppm.
Claims9
Process for reactivating used silver carrier catalysts for the manufacture of ethylene oxide by reacting ethylene with molecular oxygen or air, which comprises adjusting on the catalyst a concentration of cesium, rubidium or of both of from 1 to 1,000 ppm by impregnating the said catalyst with a solution of cesium, rubidium or of both compounds selected from the group consisting of salts and hydroxides in an aliphatic alcohol having from 1 to 6 carbon atoms and containing at most 10% by weight of water and evaporating the alcohol and any water present. ppm by impregnating the said catalyst with a solution of cesium, rubidium or of both compounds selected from the group consisting of salts and hydroxides in an aliphatic alcohol having from 1 to 6 carbon atoms and containing at most 10% by weight of water and evaporating the alcohol and any water present.
Process for improving the efficiency of used silver catalysts for the manufacture of ethylene oxide by reacting ethylene with molecular oxygen or air, which comprises adjusting on the catalyst a concentration of cesium, rubidium or of both of from 1 to 1,000 ppm by
- 1. 0.2 to 5% by weight of water
- 2. 0.05 to 0.4% by weight of cesium or rubidium nitrate and
- 3. an aliphatic alcohol having from 1 to 3 carbon atoms, and evaporating the alcohol at a temperature of from 70.degree. to 120.degree. C.
Dependencies are inferred from the claim text.