1、 Product Introduction of Organic Waste Gas Catalytic Combustion Device

Organic waste gas catalytic combustion technology refers to the rapid oxidation of hydrocarbons in organic waste gas into water and carbon dioxide at low temperatures under the action of catalysts, achieving the goal of treatment. The catalytic combustion exhaust gas treatment method for treating industrial organic waste gas was a technology that emerged in the late 1940s. Since the development of the world's first organic waste gas catalytic combustion device by the United States in 1949, this technology has been widely used in industries such as painting, rubber processing, plastic processing, resin processing, leather processing, food industry, and casting, as well as in the purification of automobile exhaust gas. China began using catalytic combustion treatment in 1973 to treat organic waste gases emitted from enameled wire drying furnaces, and subsequently conducted research in insulation materials, printing industry, and other fields, which led to the widespread application of catalytic combustion equipment.

2、 Introduction to Catalytic Combustion Exhaust Gas Treatment Equipment Technology

Catalytic combustion technology refers to a waste gas treatment method that thoroughly oxidizes and decomposes combustible components in exhaust gas under the action of a catalyst at lower temperatures, thereby purifying the gas. Catalytic combustion exhaust gas treatment is a typical gas-solid phase catalytic reaction, which essentially involves the participation of reactive oxygen species in deep oxidation. In the process of catalytic combustion, the role of the catalyst is to reduce the activation energy of the reaction and enrich the reactant molecules on the surface of the catalyst to increase the reaction rate. With the help of catalysts, organic waste gas can undergo flameless combustion at lower ignition temperatures and undergo oxidation decomposition into CO2 and H2O, while releasing a large amount of heat.

Process flowchart for catalytic combustion treatment of organic waste gas

According to the preheating and enrichment methods of organic waste gas, the catalytic combustion process can be divided into three types:

1. Preheating type.

Preheating is the basic process form of catalytic combustion, and its basic principle is shown in Figure 1. When the temperature of organic waste gas is below 100 ℃ and the concentration is also low, the heat cannot be self-sufficient, so it needs to be heated in the preheating chamber before entering the reactor. Usually, gas or electric heating is used to raise the temperature of the exhaust gas to the ignition temperature required for catalytic reactions; The purified gas after combustion undergoes heat exchange with untreated exhaust gas in a heat exchanger to recover some heat.

2. Self thermal equilibrium type.

Organic waste gas has a high temperature and organic content, usually only requiring the installation of an electric heater in the catalytic combustion reactor for use during ignition. The heat generated by partially purifying the gas is recovered through a heat exchanger, and thermal balance can be maintained under normal operation without the need for additional heat. The process is shown in Figure 2

3. Adsorption catalytic combustion.

When the flow rate of organic waste gas is high, the concentration is low, the temperature is low, and a large amount of fuel is required for catalytic combustion, adsorption can be used to adsorb the organic waste gas onto the adsorbent and concentrate it. Then, hot air blowing can be used to desorb the organic waste gas into high concentration organic waste gas (which can be concentrated more than 10 times) before catalytic combustion. Normal operation can be maintained without the need for additional heat sources. The process flow is shown in Figure 3.

The selection of catalytic combustion treatment process for organic waste gas mainly depends on:

1. The heat released during the combustion process, which refers to the type and concentration of combustibles in the exhaust gas;

2. The ignition temperature refers to the properties of organic components and catalyst activity;

3. Heat recovery rate, etc. When the recovered heat exceeds the required preheating heat, it can achieve self heat balance operation without the need for external heat sources, which is economical.

Catalytic combustion is an exothermic reaction, and the amount of heat released depends on the type and content of organic matter. It is an economical operating method to maintain the continuous catalytic combustion process by relying on the reaction heat of exhaust gas combustion. Whether the normal reaction of the self heating maintenance system can be maintained depends on the heat released during the combustion process, the ignition temperature of the catalyst, the heat recovery rate, the initial temperature of the exhaust gas, and other conditions. The corresponding ignition temperatures of the catalyst are 200 ℃, 250 ℃, and 300 ℃; The initial temperatures of the exhaust gas are 30 ℃ and 150 ℃, respectively. The higher the initial temperature of the exhaust gas, the higher the concentration of organic matter in the exhaust gas, and the greater the possibility of achieving self heating operation. The residual amount of organic matter in industrial organic waste gas of about 5000mg/m3 is common. As long as the heat exchange efficiency of the heat exchanger can reach 50% -60%, the heat exchanger can be used to recover the combustion reaction heat to maintain the continuous catalytic combustion.

Advantages of catalytic combustion exhaust gas treatment technology:

1. Low ignition temperature, saving energy

Compared with direct combustion, catalytic combustion of organic waste gas has significant characteristics of low ignition temperature and low energy consumption. In some cases, catalytic combustion does not require external heating once it reaches the ignition temperature.

2. Wide applicability

Catalytic combustion can treat almost all hydrocarbon organic waste gases and odorous gases. For low concentration, multi-component, and non recyclable waste gases emitted from industries such as organic chemicals, coatings, and insulation materials, the adsorption catalytic combustion method has a better treatment effect.

3. High processing efficiency, no secondary pollution

The purification rate of organic waste gas treated by catalytic combustion method is high, and the final products are harmless CO2 and H2O (heteroatom organic compounds and other combustion products). Due to the low combustion temperature, it can significantly reduce the generation of NOX, so it will not cause secondary pollution. However, its disadvantage is that the process conditions are strictly required, and it is not allowed for the exhaust gas to contain dust particles and droplets that affect the life and treatment efficiency of the catalyst, nor is it allowed for substances that can poison the catalyst to prevent catalyst poisoning. Therefore, when using catalytic combustion technology to treat organic exhaust gas, pre-treatment of the exhaust gas is necessary.

Spray organic waste gas is treated by pre-treatment equipment and enters the activated carbon adsorption bed+organic waste gas catalytic combustion treatment device process diagram

Process flowchart of organic waste gas treatment

Characteristics of integrated equipment for activated carbon adsorption desorption catalytic combustion treatment:

(1) The equipment is compact and can be made to integrate activated carbon adsorption, desorption, and control, with a small footprint;
(2) High adsorption purification efficiency;
(3) The catalyst used is a specialized catalyst produced by our company, with a long service life;
(4) The detachment process runs automatically, the equipment is easy to operate, and the management is convenient;
(5) This device is only suitable for situations where organic waste gas is generated intermittently.
(6) Using a thin layer of activated carbon fiber (ACF) as the adsorption unit results in high adsorption efficiency and low airflow resistance.
(7) Fast regeneration speed and low regeneration energy consumption.
(8) Adopting PLC fully automatic control and unmanned operation.
(9) The adsorption cycle of the adsorber is fast, safe, and efficient.

3、 Scope of adaptation of organic waste gas catalytic combustion device

The organic waste gas catalytic combustion device is applied in the treatment of organic waste gas in industries such as paint, rubber processing, plastic processing, resin processing, leather processing, food industry, and casting. Currently, the drying waste gas of enameled wire, coating drying organic waste gas, and ink waste gas are widely used.

4、 Model and parameters of catalytic combustion treatment equipment

5、 Engineering case of organic waste gas catalytic combustion device