CO gas-phase oxidative coupling oxalate synthesizing palladium catalyst reactivating method

Abstract

The invention discloses a CO gas-phase oxidative coupling oxalate synthesizing palladium catalyst reactivating method in coal ethylene glycol production technical synthesizing processes. The method comprises four steps of baking at high temperature CO gas-phase oxidative coupling oxalate synthesizing palladium catalyst of Pd/a-Al2O3 to remove impurities like organic matters and carbon carried by carriers, and converting palladium on the catalyst into palladium oxide; reacting the catalyst with acid to convert the palladium oxide into soluble palladium salt, and together drying and baking the reacted solution and the carriers to redistribute and load palladium products on the carriers; performing reduction treatment to obtain reactivated palladium catalyst of Pd/a-Al2O3. The reactivated catalyst can restore the quality of fresh catalyst. The CO gas-phase oxidative coupling oxalate synthesizing palladium catalyst reactivating method can effectively reactivate deactivated palladium catalyst to obtain the catalyst excellent in active indexes.

Description

technical field [0001] The invention relates to a regeneration method of a deactivated noble metal catalyst, in particular to a regeneration method after deactivation of the catalyst used in the CO gas-phase oxidative coupling synthesis process of dimethyl oxalate in the coal-to-ethylene glycol synthesis process. Background technique [0002] As of January 2016, the total production capacity of major coal-to-ethylene glycol production enterprises in my country is 2.2 million tons per year. In the next few years, multiple sets of ethylene glycol industrial devices with a capacity of more than 100 kt / a will be put into operation one after another. [0003] The coal-to-ethylene glycol technology is divided into three important processes. The first step is to remove the hydrogen from the CO in the coal synthesis gas to below 100ppm under the action of a dehydrogenation catalyst to obtain refined CO, referred to as the dehydrogenation process; the second step is Refined CO is oxi...

AI Technical Summary

Problems solved by technology

For example, the patent CN103191759A discloses a regeneration method for Pd / C catalysts. The deactivated catalyst is dried and oxidized at a temperature of 50-140°C in an air atmosphere. The disadvantage is that the lower calcination temperature cannot adsorb or The generated impurities are completely removed

Patent CN104190441A discloses an online regeneration method of deactivated palladium catalyst in the coal-to-ethylene glycol process. The deactivated catalyst is activated and regenerated in a fixed-bed reactor under high-temperature water vapor, oxygen, hydrogen and other atmospheres. The existing disadvantages Higher temperature steam treatment can easily lead to permanent deactivation of the catalyst

Patent 03122844.5 discloses a palladium catalyst regeneration method, extracting the deactivated catalyst in carbon dioxide under supercritical conditions to remove the organic impurities adsorbed on the palladium catalyst, so that the catalyst can be regenerated. The disadvantage is that harsh supercritical conditions require higher processing costs

[0006] At present, there are few reports on the regeneration method after deactivation of CO gas-phase oxidative coupling synthesis dimethyl oxalate catalyst in the coal-to-ethylene glycol synthesis process. Therefore, at the time of the rapid development of coal-to-ethylene glycol technology, a new The efficient palladium catalyst regeneration method ensures the efficient recycling of precious metals and has long-term significance for reducing the cost of the entire coal-to-ethylene glycol industrialization

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