Novel CO sulfur-tolerant shift catalyst and preparation method thereof

Abstract

The invention provides a novel CO sulfur-tolerant shift catalyst and a preparation method thereof, and a carrier of the catalyst is titanium dioxide; active ingredients comprise molybdenum and cobalt or/and nickel; and auxiliaries which refer to at least one compound of magnesium, calcium, zinc, zirconium, cerium and lanthanum also can be added in the carrier. The invention further provides the preparation method of the novel CO sulfur-tolerant shift catalyst. The catalyst has high shift activity and particularly has high low-sulfur activity and stable structure; furthermore, the catalyst has very high activity without performing prevulcanization before use, thereby simplifying the operation procedure; when the sulfur content in raw material is low (50ppm), sulfur does not need to be supplemented additionally; in addition, the catalyst further has excellent performances of anti-hydrate phase change and anti-sulfation, and can greatly expand the application range of the CO sulfur-tolerant shift catalyst.

Description

technical field [0001] The invention belongs to a catalyst and a preparation method thereof, in particular to a novel CO sulfur-tolerant shift catalyst and a preparation method. Background technique [0002] In recent years, my country's coal chemical industry has developed rapidly, and the production capacity of traditional coal chemical products represented by synthetic ammonia and methanol has expanded rapidly. [0003] All coal chemical projects use coal as raw material, and obtain hydrogen and synthesis gas through pressurized gasification and carbon monoxide shift processes. The shift processes basically use CO sulfur-tolerant shift catalysts. Therefore, the market demand for CO sulfur-tolerant shift catalysts is increasing, and the requirements for catalyst performance are becoming more and more stringent. It is very necessary to develop new catalysts. [0004] In the prior art, traditional CO sulfur-tolerant shift catalysts mainly fall into two categories: [0005]...

AI Technical Summary

Problems solved by technology

Practice has shown that this type of catalyst has shortcomings: its low-temperature activity and low-sulfur activity are poor, and it is only suitable for high pressure (3.0-10.0MPa), high water-gas ratio, high H 2 Conversion process of S concentration

However, the H in the process gas produced by low-sulfur coal gasification 2 The S content is even lower than 100ppm, so it is necessary to artificially supplement additional sulfur, otherwise the activity of the conversion catalyst will be greatly reduced due to anti-sulfurization, and normal production will be difficult to maintain

[0006] Disclosed in Chinese patent CN1096494A is a kind of sulfur-tolerant shift catalyst, and the support of this catalyst is MgO-Al 2 o 3 -TiO 2 The ternary carrier has a strong adaptability to the change of sulfur content in the process gas, allowing H in the process gas 2 The concentration of S is as low as 100ppm, but it must undergo complicated pre-sulfurization treatment before use

[0007] Chinese patent CN1089634C discloses a preparation method of a low-sulfur cobalt-molybdenum sulfur-resistant shift catalyst, which is to add an oxo acid salt to the impregnation solution of the catalyst prepared by the traditional impregnation method to change the structure of the molybdenum-sulfur compound. Improve its anti-low sulfur performance, the effect is not ideal

[0008] Another class of cobalt-molybdenum sulfur-tolerant shift catalysts is the alkali metal-promoted, Al 2 o 3 or modified Al 2 o 3 As a carrier catalyst, this type of catalyst has good low-temperature activity and high low-sulfur activity, but when used under high temperature or high water vapor partial pressure process conditions, the alkali metal in the catalyst will be lost seriously, and the activity will decline rapidly; When the dew point temperature is close (about 20°C), the catalyst has poor hydration resistance, and Al 2 o 3 It is easy to undergo hydration phase transition and irreversible deactivation, such as the catalysts described in Chinese patents CN1003979, CN87107892, and US patents US3858840 and US4153580

[0009] In summary, the above two types of CO sulfur-tolerant shift catalysts widely used in the prior art contain Al 2 o 3 Composition, start-up must go through the pre-sulfurization procedure, when the sulfur content in the raw material is low, additional sulfur must be added; under the process conditions of low temperature and close to the dew point temperature (about 20 ℃), it is easy to undergo hydration phase change and irreversible deactivation; in the process The gas contains a small amount of O 2 (0.2 ~ 0.8%) under the changing conditions, the active component or carrier will undergo sulfate reaction and lead to irreversible deactivation of the catalyst

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