Cryogenic passivation pretreatment process for nickel-based catalyst

Abstract

The invention relates to a cryogenic passivation pretreatment process for a nickel-based catalyst. The process comprises the following steps: subjecting the nickel-based catalyst to ex-situ reduction treatment by using a reducing agent to allow an active component in the nickel-based catalyst to be converted into elementary nickel from nickel oxide; when the temperature of a catalyst bed is lowered to below 300 DEG C, stopping introduction of the reducing agent, then introducing liquid carbon dioxide into a reactor, cooling the reduced catalyst and carrying out passivation treatment for 2 to 3 hours, then stopping introduction of the liquid carbon dioxide, blowing the liquid carbon dioxide in the system away by using room-temperature air; and when an outlet material does not contain the liquid carbon dioxide, completing passivation of the nickel-based catalyst. The cryogenic passivation pretreatment process for the nickel-based catalyst provided by the invention has the advantages of mild control conditions, high degree of reduction and uniform reduction; the reduced catalyst can stably exist in air and is not affected by passivation pretreatment in activity and stability at the same time; when in use, the catalyst is easy to activate, has short activation time and high shift activity, is convenient for transportation and storage, and significantly reduces working time of enterprises and adverse conditions brought by reduction of the catalyst in a device.

Description

technical field [0001] The invention relates to a catalyst reduction technology, in particular to a nickel-based catalyst cryogenic passivation pretreatment process. Background technique [0002] Nickel-based catalysts are widely used in industry, such as hydrocarbon steam reforming, methanation, hydrogenation, etc. Experiments and industrial applications have proved that only the reduction treatment of nickel-based catalysts can convert the active components in the oxidized state into elemental nickel. In order to make it have hydrogenation and dehydrogenation activity, the reduction effect of the nickel-based catalyst directly affects the performance of the catalyst. [0003] Nickel-based catalysts often adopt external pre-reduction treatment or internal reduction treatment technology, and the internal reduction treatment technology has obvious shortcomings, (a) requires special pre-reduction equipment and instruments; (b) the reduction time is long, affecting normal Star...

AI Technical Summary

Problems solved by technology

[0007] For the pre-reduction technology outside the device, only preliminary research has been carried out in China, and there are still many difficulties in realizing industrialization, and these pre-reduction methods need to establish special devices, and the investment in equipment is relatively large.