Silica Catalyst Supports for Hydration of Ethylene to Ethanol

2,500 grams of amorphous silica powder having an average particle size in the range of 10 to 50 millimicrons is dry blended with 125 grams of water-soluble starch in a Muller mixer for approximately 15 minutes. 5,700 grams of water is added to the mixture and mixed for an additional 20 minutes forming damp lumps of material of up to 2 inches in diameter. These lumps contain approximately 60-70% moisture. The lumps are dried at approximately 110.degree. C. for approximately 16 hours to reduce the moisture content to below 15% water and preferably below 5% water. The dried lumps of silica and binder are granulated to pass a 12 mesh Tyler screen and dry blended with approximately 3 weight percent graphite lubricant, e.g., Asbury No. 92 graphite. The density of this combined granulated product is approximately 0.24 gram per cubic centimeter. The mixture of granulated silica-binder and graphite is compacted to a density of approximately 0.30 gram per cubic centimeter. The compacted silica-binder and graphite is then granulated to pass a 12 mesh Tyler screen, and is tableted in a conventional tableting machine to a density of greater than 0.8 gram per cubic centimeter and preferably approximately 0.85 gram per cubic centimeter. Generally, the length to diameter ratio of the tablets is from 0.8 to 1.0. Typical tablets made utilizing conventional tableting apparatus may have the following properties:

The tablets are then charged to an electric furnace and calcined at a temperature of 1200.degree. F. for a period of 5 hours. The calcinated silica support will have the following typical properties:

540 grams of water and 12 grams of a 5% aqueous solution of polyvinyl alcohol are mixed and added to 300 grams of amorphous silica powder having an average particle size in the range of 10 to 50 millimicrons, and mixed in a Muller-type mixer for a sufficient time to obtain a homogeneous mixture, e.g., about 20 minutes. Sufficient additional water may be added to achieve a mixture having 80 to 90% water. The mixture is dried at 110.degree. C. for about 16 hours to reduce the moisture content of the mixture to less than 5%. The dried mixture of silica and binder is granulated to pass a 12 mesh Tyler screen and dry blended e.g., Asbury No. 92 graphite. This mixture may be precompacted or fed directly to a tableting machine to achieve a tablet density prior to calcining of about 0.88 gram per cubic centimeter. Typical tablets made utilizing conventional tableting apparatus may have the following properties:

The tablets are then charged to an electric furnace and calcined at a temperature of 1200.degree. F. for approximately 3 hours. The calcined silica support will have the following typical properties:

A mixture of 2265 grams of a 5% aqueous polyvinyl alcohol solution and 2,000 grams of Ludox L.S. (colloidal silica) and 400 grams of water is added to 2,500 grams of amorphous powder silica having an average particle size in the range of 10-50 millimicrons in a Muller mixer and mixed for approximately 30 minutes. The mixture is then extruded using conventional extrusion equipment. The extrudate should be somewhat brittle having the capacity of being snapped off when 3 to 4 inches long. The extrudate material is then dried in a circulating oven at 110.degree. C. for approximately 16 hours to reduce the percentage of water of the extrudate to below 5%. The dry extrudate is then calcined in an electric oven at approximately 1200.degree. F. for approximately 5 hours. The calcined silica support will have the following typical properties:

While there has been shown and described what has been considered to be the preferred embodiments of the present invention, it will be obvious to those of skill in the art that various changes and modifications may be made therein without departing from the invention.