Catalyst for ammonia decomposition, process for producing same, and method of treating ammonia

Abstract

The present invention relates to a catalyst for ammonia decomposition which is a catalyst for decomposing ammonia into nitrogen and hydrogen. The catalyst includes an active catalyst ingredient which comprises at least one transition metal selected from a group consisting of molybdenum, tungsten, vanadium, chromium, manganese, iron, cobalt, and nickel. It is preferred that (I) the active catalyst ingredient comprise at least one member selected from a group consisting of molybdenum, tungsten, and vanadium, or (II) the active catalyst ingredient comprise a nitride of at least one transition metal selected from a group consisting of molybdenum, tungsten, vanadium, chromium, manganese, iron, cobalt, and nickel, or (III) the active catalyst ingredient contain at least one iron-family metal selected from a group consisting of iron, cobalt, and nickel and further contain a metal oxide. This catalyst enables ammonia to be efficiently decomposed into nitrogen and hydrogen at a relatively low temperature and a high space velocity, whereby high-purity hydrogen is acquired.

Description

technical field [0001] The present invention relates to a catalyst for decomposing ammonia into nitrogen and hydrogen, a preparation method thereof, and an ammonia treatment method using the catalyst. Background technique [0002] Ammonia has odor, especially irritating odor, so when the content in the gas is above the odor threshold, it needs to be treated. Therefore, various ammonia treatment methods have been studied. For example, a method of oxidizing ammonia into nitrogen and water by contacting it with oxygen, a method of decomposing ammonia into nitrogen and hydrogen, and the like have been proposed. [0003] For example, Patent Document 1 discloses that when ammonia produced from a coke oven is oxidized to nitrogen and water, for example, a platinum-alumina catalyst, a manganese-alumina catalyst, a cobalt-alumina catalyst, etc. are used, and ammonia produced from a coke oven When ammonia is decomposed into nitrogen and hydrogen, for example, an ammonia treatment me...

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Problems solved by technology

[0008] However, these catalysts all have a low ammonia concentration in the process gas (specifically, 5% by volume in Patent Document 4, and 50% by volume in Patent Document 5), or low space velocity based on ammonia (specifically, Patent Document 5 4 for 642h -1 , patent document 5 is 1000h -1 , Non-Patent Document 1 is 430h -1 ) conditions, the ammonia decomposition rate was measured. Therefore, even if the ammonia decomposition rate is 100% at a relatively low temperature, it is not necessarily caused by the high performance of the catalyst.

[0009] In this way, the conventional ammonia decomposition catalysts have the problem that they cannot effectively decompose ammonia at a relatively low temperature and at a high space velocity to obtain high-purity hydrogen.

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