LQ-CF-CO Fixed Bed Zeolite Adsorption + Catalytic Oxidation (CO)

Operating Principle

The equipment uses a combination of three processes: zeolite adsorption, hot air flow desorption, and catalytic combustion to purify organic waste gas. It utilizes the characteristics of molecular sieves such as multiple micropores and a huge surface tension to adsorb organic solvents in waste gas, enabling the purified waste gas to be the first working process. After the molecular sieve adsorption is saturated, the organic solvents adsorbed on the molecular sieve are desorbed by a hot air flow and sent to the catalytic combustion bed as the second working process at a certain concentration ratio. The high-concentration organic waste gas entering the catalytic combustion bed is heated and, with the help of the catalyst and oxygen, decomposes into carbon dioxide and water.

The heat released from this decomposition is recovered by a high-efficiency heat exchanger and used to heat the high-concentration organic waste gas entering the catalytic combustion bed as the third working process. After a certain period of operation, the desorption and catalytic decomposition processes do not require additional energy heating as they reach equilibrium.

Process Flow

1. Under working conditions, the waste gas to be treated first enters the dry filter pre-treatment box to remove particulate matter, such as dust, from the waste gas to prevent this type of substance from entering the fixed bed adsorption area and causing a decrease in zeolite adsorption efficiency.  G4, F7, F9, and other materials are used for step-by-step filtration to remove dust and viscous substances based on the actual situation.

2. The pre-treated waste gas enters the fixed bed adsorption area, where VOCs in the waste gas are adsorbed and purified and then directly discharged after meeting the emission standards. After the fixed bed reaches VOCs saturation, it undergoes desorption. Fresh air is introduced by the catalytic combustion fan and heated in the heat exchanger to reach the desorption temperature before entering the saturated fixed bed to remove the saturated waste gas from the zeolite to achieve regeneration.

3. The high-concentration waste gas generated during desorption is preheated and heated by the electric heater (natural gas combustion engine) after being preheated and heated by the heat exchanger under the action of the CO system fan to reach the catalyst activity temperature (300℃), enters the catalytic bed, undergoes oxidation and decomposition reactions, and releases heat. The high-temperature gases formed by the reaction are then discharged after heat exchange with the desorption heat exchanger.

4. The heat released by the oxidation reaction will cause the gas to heat up. The high-temperature gas transfers heat to the low-temperature gas through the heat exchanger, which is used to heat the desorbed gas, thereby reducing the energy consumption required during the operation of the system. If there is still a surplus of heat, it can also be used for heating other areas of the factory.

5. To ensure compliance with emission standards, the exhaust gases, after undergoing adsorption and oxidation processes, are released through a centralized stack at a height that typically exceeds 15 meters. This height is also designed to be taller than the surrounding structures to facilitate effective dispersion of the treated emissions.

System Configuration

The zeolite fixed bed adsorption concentration device mainly consists of a waste gas pretreatment system, a zeolite fixed bed concentration adsorption system, a desorption system, a cooling and drying system, a heat exchange system, a catalytic combustion system, an emission system, an automatic electrical control system, and an online monitoring system.

Equipment Features And Advantages

1. High adsorption and desorption efficiency, strong selectivity.

2. The pressure drop produced by the zeolite fixed bed adsorption of VOCs is low, which can greatly reduce electricity consumption. The high air volume and low concentration VOC waste gas is transformed into low air volume and high concentration waste gas, and the concentration can reach 10-15 times, resulting in lower operating costs and longer service life.

3. The overall system adopts modular design, requiring less space and providing a continuous and unmanned super control mode, resulting in low maintenance costs.

Applicable Conditions

1. Improvement of non-compliant activated charcoal systems.

2. Treatment of organic materials with unknown components causing odors.

3. Situations requiring high-temperature regeneration of substances with high boiling points above 300℃.