News Center

Industry News

Company News

Home page

Types and characteristics of catalysts in Lantian Aoyu catalytic combustion equipment

2021-11-27

visits：

What material is the catalyst of catalytic combustion equipment? Catalyst is the center of catalytic combustion method. A good catalyst must have high catalytic activity, good thermal stability, high strength and long life.
In a chemical reaction process of catalytic combustion equipment, the addition of catalyst can not change the original chemical balance, only the change is the speed of chemical reaction, and before and after the reaction, the nature of the catalyst itself does not change. So how does the catalyst speed up the reaction if the catalyst does not change before and after the reaction, does the catalyst participate in the reaction? In fact, the catalyst itself participates in the reaction. It is because of its participation that the reaction changes the original path, reduces the activation energy of the reaction, and then speeds up the reaction speed. For example, the reaction has a catalytic activity temperature, which is called the catalyst ignition temperature for catalytic combustion. It is necessary to make the temperature of the waste gas and the bed reach the ignition temperature for catalytic combustion. Preheating equipment must be set. But for the exhaust gas itself high temperature occasions, such as enameled-wire, insulation materials, baking paint and other drying exhaust, the temperature can reach more than 300℃, there is no need to set preheating equipment.

Metal-supported catalysts for catalytic combustion are generally made of metal into a wire mesh or strip, and then the active components are deposited on it. The advantages of metal-supported catalyst are good thermal conductivity, high mechanical strength, and small specific surface area. Ceramic carrier structure has two categories: granular and honeycomb, ceramic materials are generally silica-aluminum oxide. The advantages of granular carrier are large specific surface area, while the disadvantages are large pressure drop and the friction loss of active components caused by the conflict between carriers. Honeycomb carrier is the ideal carrier type, has a high specific surface, lower pressure drop than the pellet columnar, high mechanical strength, wear resistance, heat shock resistance.

With the extension of time during the use of catalyst, the activity will gradually decline until deactivation. There are three main types of catalyst deactivation:

(1) Complete deactivation of catalyst. Catalysts are inactivated by both fast - and slow-acting poisons. Rapid effect poisons mainly include phosphorus, arsenic, etc., slow effect poisons include lead, zinc, etc. In general, the deactivation of the catalyst is due to the combination of the poison with the active component or melting into an alloy. For fast-acting poisons, even in trace amounts, catalytic combustion equipment can deactivate catalysts quickly. At below 500℃, slow-acting poisons alloyed the active substance much more slowly.

(2) catalytic response. Halogen and sulfur compounds readily bind to the active intermediate, but this binding is relatively relaxed, reversible, and temporary. When such substances are removed from the exhaust gas, the catalyst activity can recover.

(3) Deposition covers the active intermediate. The presence of unsaturated compounds leads to the deposition of carbon, in addition to ceramic dust, ferric oxide and other particulate matter blocking the active intermediate, and then affect the adsorption and desorption capacity of the catalyst, resulting in the decline of catalyst activity.

催化燃烧设备

Next -

Factors influencing the treatment effect of catalytic combustion equipment

Back