Catalyst of reaction for removing oxynitrides by methane and preparation method thereof

Abstract

The invention provides a catalyst for oxynitride removing reaction by using methane, as well as a preparation method thereof. The catalyst is characterized in that a carrier of the catalyst is an H-Beta / Mordenite double-micropore molecular sieve; an active ingredient is cobalt; the weight percentage of the cobalt is between 0.5 and 10 percent; and the weight percentage of H-Beta / Mordenite is between 90 and 99.5 percent. The preparation method for the catalyst adopts an ion exchange method, which is to put H-Beta / Mordenite double-micropore molecular sieve powder into cobalt acetate solution with the concentration of between 0.005 and 0.03mol / L to react for 24 hours at 90 DEG C, wash, filter, dry and roast the powder to obtain the catalyst. The catalyst can allow the conversion rate of oxynitride to reach over 90 percent, has no inactivation phenomenon after maintaining activity for 72 hours, is wide in the operation interval (between 400 and 650 DEG C) of reaction temperature, and shows good performances of resisting water and sulfur at the same time.

Description

technical field [0001] The invention relates to a catalyst for removing nitrogen oxides and a preparation method thereof, in particular to a catalyst for removing nitrogen oxides from methane under oxygen-enriched conditions and a preparation method thereof. Background technique [0002] Nitrogen oxides cause great harm to the ecological environment and human health, and the removal of nitrogen oxides has attracted great attention from all over the world. Existing NH 3 Selective catalytic reduction of nitrogen oxides has been successfully applied to the removal of nitrogen oxides from stationary sources. But NH as a reducing agent 3 There are problems with storage, transportation, pipeline blockage and corrosion, and high operating costs. Therefore, using low-carbon hydrocarbons as reducing agents to eliminate nitrogen oxides is more and more popular. Since methane is abundant, cheap and readily available, and exists in the tail gas of almost every fuel, selective cataly...

AI Technical Summary

Problems solved by technology

U.S. Patent US5149512 reports that the Co-ZSM-5 catalyst prepared by the ion exchange method has the best activity, but the highest conversion rate of nitrogen oxides is only 34%; another U.S. Patent US5260043 improves Co-ZSM by adding rare earth metals and precious metals, etc. -5 catalyst activity, but the effect is not obvious, and the preparation method is relatively complicated

Chinese patent CN1408477A improves the activity of Co-ZSM-5 catalyst by adding cheap zinc, but the highest conversion rate of nitrogen oxides on the Zn-Co-ZSM-5 catalyst after adding zinc promoter is only 57%

[0003] The disadvantages of the above-mentioned existing catalysts are that the catalyst activity is low, and the active temperature range is narrow, and the stability and water resistance and sulfur resistance are poor.