CN108543535B

CN108543535B - Catalyst and method for denitration of coal combustion high-temperature flue gas

Info

Publication number: CN108543535B
Application number: CN201810456494.2A
Authority: CN
Inventors: 王研
Original assignee: Individual
Current assignee: Shandong Jinyuan Environmental Protection Technology Co., Ltd.
Priority date: 2018-05-14
Filing date: 2018-05-14
Publication date: 2021-09-07
Anticipated expiration: 2038-05-14
Also published as: CN108543535A

Abstract

The invention provides a catalyst and a method for denitration of coal combustion high-temperature flue gas, wherein the catalyst comprises the following components: a carrier; and the active substance comprises a composite oxide loaded on the carrier, wherein the active substance accounts for 1-5% of the mass of the catalyst. By adopting the technical scheme of the invention, when the catalyst is placed in the flue of the boiler, the catalyst is prepared from gamma-Al₂O₃As a carrier, the mechanical strength of the catalyst can be further enhanced, and the service life of the catalyst can be prolonged.

Description

Catalyst and method for denitration of coal combustion high-temperature flue gas

Technical Field

The invention relates to the technical field of flue gas denitration, in particular to a catalyst and a method for high-temperature flue gas denitration by coal combustion.

Background

At present, the reducing agent for catalytic denitration mainly comprises NH₃,CH₄And H₂When using NH₃When used as a reducing agent, NH is generated due to strong corrosivity of pipelines and equipment and high required reaction temperature₃The escape phenomenon is inevitable and excessive NH exists₃Secondary environmental pollution and industrial NH₃The preparation also needs to consume a large amount of energy; with CH₄In the presence of CH as reducing agent₄Activation is difficult, the reaction temperature is too high (600-; with H₂When used as a reducing agent, although the reaction temperature is relatively low (<300 ℃ C.), but H₂Is inconvenient in source, transportation and storage, and the flue gas contains an excessive amount of O₂Has a great inhibition effect on the reaction. In addition H₂Is inflammable and explosive, and is dangerous to operate, so that industrialization is difficult to realize.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art or the related art.

To this end, one aspect of the present invention is to provide a catalyst.

In another aspect of the invention, a method for denitration of coal combustion high-temperature flue gas is provided.

In view of the above, the technical solution of the first aspect of the present invention provides a catalyst, including: a carrier; and the active substance comprises a composite oxide loaded on the carrier, wherein the active substance accounts for 1-5% of the mass of the catalyst.

Further, the carrier is gamma-Al₂O₃。

Further, the composite oxide is an iron-cerium composite oxide, and the proportion of the iron-cerium composite oxide is 1: 9-9: 1.

The technical scheme of the second aspect of the invention provides a method for denitration of coal combustion high-temperature flue gas, which comprises the following steps: the catalyst in the technical scheme of the first aspect is placed in a flue at the tail part of a boiler, and CO gas is introduced.

One or more technical solutions provided in the embodiments of the present application have at least the following technical effects or advantages:

1. when the catalyst is put into the flue of a boiler, the mechanical strength of the catalyst can be further enhanced and the service life of the catalyst can be prolonged because the catalyst takes gamma-Al 2O3 as a carrier.

CO is used as a reducing agent, is easy to activate and can reduce NOx. The CO source is wide, the CO can be directly obtained from the flue gas, the generation is easy, the escape phenomenon of the CO does not need to be considered, the secondary pollution of the environment is not caused, and the environmental benefit is good.

3. The method takes the flue as a reactor, has simple equipment, does not need subsequent process equipment, has low investment, low energy consumption and good denitration effect, and has the advantages of simple equipment, low energy consumption and high denitration conversion rate. After the redundant CO gas is removed in the subsequent process, the secondary pollution is not caused, and the method has good environmental benefit.

Additional aspects and advantages of the invention will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the invention.

Detailed Description

So that the manner in which the above recited aspects, features and advantages of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. It should be noted that the embodiments and features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, however, the present invention may be practiced in other ways than those specifically described herein, and therefore the scope of the present invention is not limited by the specific embodiments disclosed below.

Example 1:

a catalyst according to an embodiment of the invention comprises: a carrier; the active substance comprises a composite oxide loaded on a carrier, wherein the active substance accounts for 1-5% of the mass of the catalyst.

The catalyst contains a carrier, active substances with catalytic action in the catalyst are loaded on the carrier, the structure of the catalyst is more stable and reliable, and when the catalyst is placed in a chimney, the carrier can further improve the mechanical strength of the catalyst. The catalyst is matched with a reducing agent, so that NOx can be effectively reduced.

Further, the carrier is gamma-Al₂O₃。

γ-Al₂O₃As the carrier, the mechanical strength of the catalyst can be further improved.

Further, the composite oxide is an iron-cerium composite oxide, the ratio of the iron-cerium composite oxide is 1: 9-9: 1, and the iron-cerium composite oxide is used as an active substance with a catalytic effect, so that the denitration efficiency is further improved.

Example 2:

the method for denitration of coal-fired high-temperature flue gas provided by the embodiment of the invention comprises the following steps: the catalyst of example 1 was placed in the boiler tail flue and CO gas was introduced.

Introducing blast furnace gas with CO gas as main component into a boiler flue to mix with coal-fired flue gas, consuming oxygen in the flue gas, passing the mixed gas through an iron-cerium composite oxide catalyst, and utilizing the catalysis of the iron-cerium composite oxide to perform reduction reaction on the adsorbed NOx and the CO so as to reduce the NOx into harmless N₂. The redundant CO gas is catalyzed and oxidized by iron-cerium composite oxide, and partial air is introduced to oxidize the redundant CO gas into CO₂A gas.

At the temperature of 600-800 ℃, the mixed gas contains NO, CO and N₂The simulated flue gas of (2) was introduced into a catalyst sample of iron cerium composite oxide (Fe: Ce ═ 1:9) at a rate of 500ml/min, and the denitration efficiency was measured, and the results are shown in table 1.

TABLE 1

As can be seen from Table 1, the catalyst is placed in the flue at the tail of the boiler, and CO gas is introduced, so that the catalyst has good catalytic activity in the temperature range of 600-800 ℃, and the denitration conversion rate in the boiler can reach more than 80%. The method takes the flue as the reactor, has simple equipment, does not need subsequent process equipment, and has less investment, low energy consumption and good denitration effect. After the redundant CO gas is removed in the subsequent process, the secondary pollution to the environment can not be caused, and the method has good environmental benefit.

The technical scheme of the invention is explained above, and the mechanical strength of the catalyst is further enhanced and the service life of the catalyst is prolonged through the technical scheme of the invention; CO is used as a reducing agent, is easy to activate and can reduce NOx. The CO source is wide, the CO can be directly obtained from the flue gas, the generation is easy, the escape phenomenon of the CO does not need to be considered, after the redundant CO gas is removed in the subsequent process, the secondary pollution to the environment is not caused, and the environmental benefit is good.

In the description herein, the description of the terms "one embodiment," "some embodiments," "specific embodiments," etc., means that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A coal combustion high-temperature flue gas denitration catalyst suitable for a temperature range of 700-800 ℃ is characterized by comprising the following components:

a carrier, wherein the carrier is gamma-Al₂O₃；

An active material comprising a composite oxide supported on the carrier,

wherein the active substance accounts for 1-5% of the catalyst by mass percent;

the composite oxide is an iron-cerium composite oxide, and the proportion range of the iron-cerium composite oxide is 1: 9-9: 1.

2. A method for denitration of coal combustion high-temperature flue gas is characterized by comprising the following steps:

the catalyst of claim 1 is placed in a boiler tail flue, CO gas is introduced, and the temperature of coal combustion high-temperature flue gas in the boiler tail flue is 700-800 ℃.