A kind of vanadium-based SCR catalyst regenerated catalytic powder and preparation method thereof

Abstract

The invention discloses a vanadium-based SCR catalyst regenerated catalytic powder and its preparation method. The method is to first clean and pulverize the discarded vanadium-based SCR catalyst, then add a redispersant to it and stir and mix at room temperature, and then After roasting and ball milling, regenerated catalytic powder with a particle size of D50 = 2 to 20 μm can be obtained. The components of the catalytic powder include: 0.1 to 5% wt V 2 O 5 , 80~98%wt TiO 2 ,1~10%wt WO 3 . The method of the present invention adds a redispersant solution to the cleaned and pulverized waste vanadium-based SCR catalyst, so that the agglomerated vanadium, tungsten and other active components can be redispersed, which not only restores the original catalytic structure of the catalyst, but also solves the problem of The problem of sintering and agglomeration of active components also solves the problem of catalysts that cannot be regenerated due to reduced mechanical strength or brokenness. The preparation process is simple, the cycle is short, and it is easy to operate and control. It is very suitable for industrial mass recycling production.

Description

technical field [0001] The invention belongs to the technical field of regenerated catalytic powder and its preparation method, and in particular relates to a vanadium-based SCR catalyst regenerated catalytic powder and a preparation method thereof. Background technique [0002] Selective catalytic reduction (SCR) technology is an important flue gas denitrification technology, and denitrification catalyst is one of the key technologies. According to statistics, by the end of 2015, the total number of SCR implementation projects completed nationwide had reached 670 million KW, and a large number of denitrification catalysts were used in these projects, most of which were vanadium-based SCR catalysts. As we all know, the service life of vanadium-based SCR catalysts is short, and generally deactivates in about 3 years and needs to be replaced. However, because the vanadium in the deactivated vanadium-based SCR catalyst has strong biological toxicity, the disposal of the spent ...

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Problems solved by technology

However, the deactivation of vanadium-based SCR catalysts is often accompanied by severe sintering, that is, the vanadium and tungsten species in the catalyst have aggregated into clusters and crystals from a fresh state of good dispersion, and the dispersibility is severely reduced, which leads to its catalytic degradation. The activity is significantly reduced; and the accumulation of vanadium species will further lead to SO 2 Increased oxidation rate, affecting durability of regenerated catalyst

Therefore, if the catalyst that has been used for a long time and is accompanied by severe sintering is ground and added to the new catalyst prepared as part of the raw material, it will cause the newly added active components to further aggregate into the ground old catalyst during the preparation process. In the agglomeration of materials, the deterioration of performance is accelerated—that is, the agglomeration phenomenon is aggravated, so that SO 2 The oxidation rate is further increased, and the service life is further shortened

In addition, these methods need to add a large amount of expensive active components such as tungsten, vanadium, and molybdenum when preparing new regenerated catalysts, which will also lead to increased regeneration costs.

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