CS264165B1 - Catalyst support for vinyl acetate production - Google Patents

Abstract

Catalyst carrier for the production of vinyl acetate based on products of carbonization of wood raw material containing 92.5 to 97.2 wt. % carbon and 4.8 to 7.5 wt. % ash of composition 5.8 to 7.3 wt. % S1O2, 8.1 to 9.6 wt. % K2CO3, 1.3 to 2.6 wt. % Na2CO3, 70.0 to 73.5 wt. % CaO, 2.4 to 3.3 wt. % MgO and 5.7 to 7.6 wt. % iron oxides. The carrier is activated with the addition of potassium salt by steam at a temperature of 850 to 1,050 °C to the required parameters of liter weight and total pore volume.

Description

BACKGROUND OF THE INVENTION The present invention relates to a catalyst for the production of vinyl acetate based on wood charring products with KOH addition and water vapor activation.

Several solutions are currently being developed that address the various properties of activated carbon and catalyst support to improve the catalytic activity of the vinyl acetate catalyst obtained. The active carbon catalyst carrier with a suitable porous structure and a suitable content of inorganic compounds is not practically elaborated in the available literature. Due to the use of an unsuitable catalyst carrier, a catalyst is prepared for the production of vinyl acetate of unsatisfactory technical-economic parameters.

The present invention overcomes these drawbacks by specifying both the composition and the appropriate porous structure of the catalyst support which, after impregnation with zinc salts (to about 10% Zn in the catalyst), provides a catalyst for producing vinyl acetate of optimal technical-economic parameters.

SUMMARY OF THE INVENTION The present invention provides a catalyst support for the production of vinyl acetate based on wood charred products, which contains 92.5 to 97.2% by weight of wood. % of carbon and 4.8 to 7.5 wt. ash composition:

5.8 to 7.3 wt. % silicon dioxide 8.1 to 9.6 wt. potassium carbonate

1.3 to 2.6 wt. % sodium carbonate 70.0 to 73.5 wt. calcium oxide

2.4 to 3.3 wt. of magnesium oxide

5.7 to 7.6 wt. iron oxide

The process for activating the catalyst support is carried out with 0.8 to 1.4 wt. of potassium in a carbonaceous mixture and with water vapor at a temperature of 850 to 1050 ° C to achieve a liter weight of 340 to 390 kg / m ³ and a total pore volume of 1.0 to 1.35 cm ³ . g ^-1 with a maximum pore in the region of the pore radius of 500 to 2 000 nm.

Among the main advantages of the vinyl acetate catalyst support according to the invention is the fact that by using less valuable wood raw material with an ash content of 5 to 7.5% by weight. with the addition of KOH as well as the presence of potassium salt and other inorganic compounds, the desired optimum concentration of the promoter elements as well as the optimum porous structure are achieved.

The detailed characteristics of the vinyl acetate catalyst support are evident from the example.

Example 1

100.0 kg charcoal of less than 0.07 mm ash content

6.7 wt. composition

6.7 «/ 0 S1O2 9.3 % K2CO3 1.7 % Na ₂ CO3 72.6 % CaO 2.8 0/0 MgO 6.8 ° / o iron oxides

66,0 kg distilled wood tar

1.5 kg of KOH 25.0 kg of water are mixed and kneaded at a temperature of 50 to 70 ° C to form a plasticized carbon blend which is formed into granules having a diameter of 3 to 5 mm.

The granules are dried and stripped of most of the volatiles by carbonization in rotary kilns at 150-550 ° C.

The carbonized granules are exposed to water vapor and heating fumes. At temperatures of 900 to 1000 ° C, the activation process takes place to form a porous structure by the action of the water vapor and CO 2 present in the fuel gas and also formed as a product of the water vapor and carbon reaction. The activation process under these conditions resulted in a total porosity of the carrier of 1.2 cm ³ . g ^_1 and a liter weight of 370 kg / m ³ .

Claims (2)

Catalyst carrier for the production of vinyl acetate based on activated charcoal, characterized in that it contains 92.5 to 97.2 wt. % of carbon and 4.8 to 7.5 wt. an ash composition of 5.8 to 7.3 wt. % silica, 8.1 to 9.6 wt. % potassium carbonate, 1.3 to 2.6 wt. % sodium carbonate, 70-73.5 wt. % calcium oxide, 2.4 to 3.3 wt. % magnesium oxide and 5.7 to 7.6 wt. iron oxide. 2. A process according to claim 1, wherein the support is treated with a potassium salt containing 0.8 to 1.4% by weight of the catalyst support. % of the potassium in the carbonaceous mixture and the carrier is selectively activated with steam at 850 to 1050 ° C to a liter weight of 340 to 390 kg / m ³ for a total pore volume of 1.0 to 1.35 cm ³ . g ^-1 , with a maximum pore in the pore radius range of 500 to 2000 nm.