Method for regenerating deactivated palladium catalyst on line in process of preparing ethylene glycol through coal

Abstract

The invention discloses a method for regenerating a deactivated palladium catalyst on line in process of preparing ethylene glycol through coal. The whole regeneration process is performed in a conventional fixed bed reactor. The process comprises the following steps: respectively introducing water vapor to remove partial organic matters and inorganic matters attached to the surface of the catalyst at different temperatures, introducing N2 to dredge a carrier pore channel, introducing O2 to remove carbon deposit on the catalyst, oxidizing and dispersing the aggregated palladium in a reduced state, introducing H2 to reduce and re-disperse active ingredients, and regenerating the catalyst so as to basically restore the activity of the catalyst, wherein the performance of the catalyst is slightly lower than that of a fresh catalyst, and the catalyst can be continuously used for half a year. According to the regeneration method adopted by the invention, the catalyst does not need to be discharged out of the fixed bed, and the method is simple, economical and easy to operate and has significance in developing a technology of producing ethylene glycol through coal.

Description

technical field [0001] The invention relates to a regeneration method of a deactivated noble metal catalyst, in particular to an online regeneration method of a deactivated palladium catalyst in coal-to-ethylene glycol technology. Background technique [0002] Since the world's first 200,000-ton coal-to-ethylene glycol industrial demonstration plant was tested in Tongliao, Inner Mongolia, in December 2009, there has been an upsurge in the development and industrialization of coal-to-ethylene glycol technology at home and abroad. At present, my country has built And the proposed coal-to-ethylene glycol industrial plant exceeds 5 million tons. [0003] The coal-to-ethylene glycol technology is divided into two steps. The first step is carbon monoxide carbonylation coupling to synthesize oxalate. The second step is hydrogenation of oxalate to prepare ethylene glycol. , involving two catalytic reactions, respectively dehydrogenation and purification of carbon monoxide raw materi...

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Problems solved by technology

[0008] It can be seen that the above regeneration method either requires the introduction of organic matter and / or acid to fully contact the catalyst, or the treatment temperature needs to exceed 500°C, and the activation of the catalyst needs to be disassembled from the device for activation treatment, which is not environmentally friendly, and the process is cumbersome and time-consuming.

[0009] At present, there is no regeneration method after the deactivation of the palladium-containing catalyst used in the coal-to-ethylene glycol technology. Therefore, a regeneration method suitable for the deactivation of the palladium-containing catalyst used in the coal-to-ethylene glycol technology is developed, so that the entire regeneration process can It is carried out in the existing fixed-bed reactor, which can not only save the regeneration time, but also has low cost, which is of great significance for the development of coal-to-ethylene glycol technology

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