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Palladium carbon catalyst for hydrogenation and refining of crude terephthalic acid

A crude terephthalic acid, hydrogenation and refining technology, applied in the direction of metal/metal oxide/metal hydroxide catalyst, physical/chemical process catalyst, carboxylate preparation, etc., can solve the problem of easy loss of palladium and low catalyst activity and other problems, to achieve the effect of low palladium loss rate, high activity and good technical effect

Active Publication Date: 2015-04-08
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0004] The technical problem to be solved by the present invention is that the palladium-carbon catalyst existing in the prior art is easy to lose palladium during use, causing the problem of low catalyst activity, and a new catalyst for crude terephthalic acid hydrotreating is provided, the catalyst It is used in the hydrofining reaction of crude terephthalic acid, which has the characteristics of reducing the loss of active component metal palladium and high catalyst activity.

Method used

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  • Palladium carbon catalyst for hydrogenation and refining of crude terephthalic acid
  • Palladium carbon catalyst for hydrogenation and refining of crude terephthalic acid
  • Palladium carbon catalyst for hydrogenation and refining of crude terephthalic acid

Examples

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Effect test

Embodiment 1

[0025] Weigh 50 grams of 4-8 mesh, flaky coconut shell activated carbon, with a specific surface of 1100m 2 / g, the pore volume is 0.52ml / g. After removing the dust adsorbed on the surface and the loose parts on the surface, pickle with 0.5N nitric acid in a washing tank at a washing temperature of 80°C for 1 hour, and then wash with deionized water until neutral. and dried at 120° C. for 2 hours. Weigh 1.25 grams of palladium-containing 20% ​​chloropalladium acid solution, adjust the pH value of the solution to 5.5 with 10% sodium carbonate, then add 5 grams of acetic acid-sodium acetate buffer solution with a pH of 5.5, add deionized water to the amount of the solution It is advisable to just immerse the activated carbon carrier. The catalyst active component solution is impregnated with the carrier, aged for 24 hours, then reduced with sodium formate solution, then washed with pure water until there is no chloride ion and dried to obtain a catalyst product. Catalyst anal...

Embodiment 2～8

[0027] Except that the drying temperature, the type of buffer solution, the amount of precursor and the pH value are different, the others are the same as [Example 1]. The specific conditions are shown in Table 1. Catalyst analysis data and catalyst activity evaluation data are shown in Table 2.

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Abstract

The invention relates to a palladium carbon catalyst for hydrogenation and refining of crude terephthalic acid, which mainly solves the problem of the prior art that the activity of the catalyst is low due to easiness in loss of palladium in the use process of the palladium carbon catalyst. Aiming at well solving the problem, the palladium carbon catalyst adopts the technical scheme that the formed active carbon is used as a carrier, wherein the content of the palladium in percentage by mass is 0.30% to 0.80%, 60% to 75% of palladium is distributed on a 0.2-2.0mu.m surface layer, less than 10% of palladium is distributed on a 0-0.20mu.m surface layer, and the balance palladium is distributed on a 20-180mu.m inner surface. The method can be used for the industrial production of the hydrogenation and refining of the crude terephthalic acid.

Description

technical field [0001] The invention relates to a catalyst used for hydrogenation refining of crude terephthalic acid. Background technique [0002] The supported palladium / carbon catalyst is suitable for the purification of crude terephthalic acid. After the impurities such as p-carboxybenzaldehyde (4-CBA for short) in crude terephthalic acid are hydrogenated into other compounds, the method of crystallization is subsequently adopted. to separate and purify. Since the palladium / carbon catalyst adopts a single active component, the distribution of metal palladium on the carrier has a great influence on the performance of the catalyst. [0003] Since the reaction process of terephthalic acid hydrofining is a first-order reaction, the reaction speed is fast, and it is difficult for the reactants to penetrate into the interior of the catalyst particle for reaction during the reaction process, which makes the active metal inside the particle due to steric hindrance. The molecu...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): B01J23/44B01J35/10C07C63/26C07C51/487
Inventor 肖忠斌畅延青朱小丽
Owner CHINA PETROLEUM & CHEM CORP