CS240277B1 - Process for preparing a fural hydrogenation catalyst - Google Patents

Abstract

The aim of the invention was a method for preparing a catalyst for the hydrogenation of fural, consisting of a layer of metallic copper on the surface of silicon dioxide, which would allow the production of a catalyst with higher activity. The aim was achieved by preparing the catalyst by reacting water glass with copper formate or acetate and subsequently reducing the resulting copper silicate.

Description

(54) A process for preparing a catalyst for hydrogenation of fural

2

SUMMARY OF THE INVENTION It is an object of the present invention to provide a catalyst for the hydrogenation of a fural, consisting of a metallic copper layer on a silica surface, to produce a catalyst having a higher activity.

The objective was achieved by preparing a catalyst by reacting waterglass with cuprous formate or acetate and subsequently reducing the resulting cupric silicates.

The invention relates to a process for the preparation of a catalyst. a copper metal layer on a silica surface which is used to catalyze some hydrogenation reactions, e.g., hydrogenation, furanyl, furfuryl alcohol. , j ·

So far, this catalyst is prepared by first reacting a waterglass with sulfate, most often copper nitrate, according to the reaction.

Cu (NO 3) 2 + Na 2 SiCl 2 - * CuSiCl 2 - Na 2 NaNO 3

The copper silicate thus formed is reduced after washing with water and drying at temperatures of about 280 DEG C. in reducing furnaces.

CuSiO3 + Hz Cu + SiO2 + H2O

The disadvantages of the present state of the art are that the precipitation of cupric silicate requires the control of the pH of the reaction mixture, where a small amount of water glass precipitation solution may decide at the end of the precipitation between pH 6 and pH 11.

When water glass is overdosed, the pH of the reaction mixture becomes alkaline, excess sodium silicate envelops the surface of the silicate, which has negative consequences in further processing and any acidification will no longer help.

A further disadvantage is that the catalyst prepared in this way has a low activity, is coarse, which implies that it has a small surface area. Another disadvantage is that it is easily bridged during handling.

These disadvantages are overcome by a process for preparing a catalyst for the hydrogenation of fural, consisting of a layer of metallic copper on the silica surface, by reacting waterglass with copper salt and reducing the resulting copper silicate at 250-300 ° C according to the invention. For example, formic acid or copper acetate may be added to an aqueous medium, a dosage of copper or copper acetate, up to a range of β to 6.5.

The advantages of the process according to the invention are that when the copper silicate is precipitated by the reaction of water glass with cuprous formate or acetate, the reaction mixture is clear, only after reaching pH 6 a copper silicate precipitate is formed, and the reaction can be terminated without glass.

The precipitated copper silicate is dried more quickly and drying is less energy intensive. During drying, copper silicate disintegrates into fine, shiny crystals, is free-flowing and therefore does not bridge.

The main advantage of the catalyst prepared by the process of the invention is its activity of up to 40 to 50% / higher.

He did.

A solution of 25 kg of Cu (HCOO) 2 in 130 l of water is slowly added to 73 kg of 50 ° Be waterglass with stirring until a cyan-blue copper silicate precipitate forms in the reaction mixture and the pH of the reaction mixture is in the range of 6, 0 to 6.5. After filtration and drying, 20.5 kg of copper silicate is obtained, which is further reduced in a reduction furnace at 250 ° C.

Example 2

A solution of 27 kg of copper acetate in 130 l of water is slowly added to 73 .mu.g of 50 ° Be water glass. The resulting azure-blue copper silicate precipitate is filtered off, dried and then reduced in a conventional manner in a reducing oven at 250 ° C.

Claims (1)

Subject Process for preparing a catalyst for hydrogenation of fural, by reacting waterglass with cupric salt and reducing the resulting cupric silicate at a temperature of 290 to 300 ° C, characterized in that cupric silicate is prepared by reacting waterglass with cupric or cupric acetate in an aqueous medium by dosing formate or acetate % copper in water glass until a pH in the range of 6 to 6.5 is reached.