Product Overview

The zeolite rotor adsorption and desorption system is specially designed for treating industrial organic exhaust gas with a high airflow rate and a low VOC concentration.

During operation, VOC molecules in the incoming exhaust gas are captured by the hydrophobic zeolite molecular sieve inside the rotating rotor. As the rotor continuously turns, the saturated adsorption section moves into the desorption zone, where hot air at approximately 180–220°C releases the adsorbed VOCs.

The desorption airflow generally accounts for only 5%–10% of the total treatment airflow. This process converts a large-volume, low-concentration exhaust stream into a small-volume, high-concentration VOC stream. The concentrated gas can then be sent to an RTO or catalytic oxidation system for further decomposition into carbon dioxide and water vapor.

After desorption, the regenerated section of the zeolite rotor passes through the cooling zone. Once cooled, it returns to the adsorption zone and begins the next cycle. The system therefore operates continuously through adsorption, desorption and cooling.

The hydrophobic zeolite material efficiently captures VOCs from the airflow, while the purified exhaust gas is discharged after meeting the applicable emission requirements.

Working Principle

Large-volume, low-concentration organic exhaust gas is first collected through an extraction hood and transported through ductwork to the pretreatment and cooling system.

The cooling system reduces the exhaust gas temperature to a range suitable for zeolite adsorption. The conditioned gas then passes through a fire damper and enters the adsorption zone of the zeolite rotor.

Hydrophobic zeolite molecular sieves capture organic compounds from the exhaust gas. After adsorption and concentration, the purified gas is drawn by an induced-draft fan and discharged through the exhaust stack.

The rotor is normally divided into multiple operating sections, commonly around 12 sectors, and rotates continuously at a controlled speed. When one section approaches adsorption saturation, it enters the desorption zone.

Hot air is introduced into the desorption zone to release the concentrated VOCs. The desorbed gas concentration can typically reach approximately 2–3 g/m³, depending on the inlet conditions and concentration ratio.

The concentrated VOC stream is then delivered to an RTO or catalytic oxidation unit for thermal treatment. After desorption, the rotor section enters the cooling zone, where process air removes residual heat before the section returns to adsorption.

Each rotor section sequentially completes adsorption, desorption and cooling, forming a continuous treatment cycle.

Process Flow

Process Stage	Description
1. Exhaust Gas Collection	Organic exhaust gas is collected through extraction hoods and transported through the duct system.
2. Pretreatment and Cooling	Dust, oil mist and other contaminants are removed, while the gas temperature is reduced to a suitable adsorption range.
3. Zeolite Adsorption	Hydrophobic zeolite molecular sieves adsorb VOCs from the large-volume, low-concentration exhaust gas.
4. Purified Gas Discharge	The treated gas is drawn through the system by the induced-draft fan and discharged through the exhaust stack.
5. Hot-Air Desorption	Hot air at approximately 180–220°C removes adsorbed VOCs from the saturated rotor section.
6. VOC Concentration	The original exhaust gas is concentrated into a smaller airflow with a higher VOC concentration.
7. Oxidation Treatment	The concentrated VOC stream enters an RTO or catalytic oxidation system and is decomposed into carbon dioxide and water vapor.
8. Rotor Cooling	The regenerated rotor section is cooled before returning to the adsorption zone.

Key Advantages

• Designed for high-air-volume, low-concentration VOC exhaust gas
• Typically concentrates VOC exhaust gas by approximately 5–20 times
• Hydrophobic zeolite rotor provides strong and selective VOC adsorption
• High-temperature regeneration supports a long service life
• VOC removal efficiency can exceed 90% under suitable operating conditions
• Significantly reduces the airflow entering the downstream oxidation system
• Lower energy consumption compared with treating the full airflow directly in an RTO
• Operating energy can be substantially reduced when oxidation heat is reused for desorption
• Non-combustible zeolite material improves system safety
• No secondary pollution when combined with complete oxidation treatment
• Compact rotor structure reduces equipment footprint
• PLC automatic control combined with manual operating functions
• Fire dampers and multiple monitoring sensors improve operating stability
• Rotor modules can be cleaned if the honeycomb channels become blocked
• Zeolite adsorption performance can be restored through high-temperature activation when necessary

Zeolite Molecular Sieve Rotor Concentration Technology

Direct combustion treatment of exhaust gas with an airflow of 50,000 CMH or more and a VOC concentration of approximately 200 mg/m³ or less may require large equipment and high operating costs.

A zeolite rotor concentrator converts this large-volume, low-concentration exhaust gas into a smaller-volume, higher-concentration gas stream. Depending on the working conditions, the concentration ratio can typically reach approximately 15–20 times.

This concentration process reduces the treatment airflow entering the RTO or RCO system, improves oxidation efficiency and lowers both equipment investment and fuel consumption.

The zeolite rotor system operates continuously through adsorption, desorption, concentration and oxidation. The adsorption module is normally manufactured from ceramic fiber, hydrophobic zeolite molecular sieves and inorganic binders.

These materials are formed into a honeycomb structure using a wet-forming process and assembled into a large circular rotor according to the required airflow and pollutant characteristics.

A complete zeolite rotor concentration system generally consists of the following sections:

• Exhaust gas pretreatment system
• Zeolite molecular sieve rotor adsorption system
• Hot-air desorption system
• Cooling and drying system
• Automatic control system
• RTO or RCO downstream oxidation system

Technical Features

Item	Typical Description
Suitable Exhaust Gas	High airflow and low VOC concentration
Adsorbent	Hydrophobic zeolite molecular sieve
Desorption Temperature	Approximately 180–220°C, adjustable according to VOC properties
Desorption Airflow	Approximately 5%–10% of the total treatment airflow
Typical Concentration Ratio	Approximately 5–20 times
VOC Removal Efficiency	Generally above 90% under suitable design and operating conditions
Downstream Treatment	RTO or RCO oxidation system
Rotor Operation	Continuous adsorption, desorption and cooling
Control Method	PLC automatic control with manual operating mode
Safety Configuration	Fire damper, temperature sensors and system interlocks
Customization	Designed according to airflow, VOC composition, concentration, temperature and humidity

Factors Affecting Adsorption Efficiency

1. Rotor Speed

Rotor speed directly affects adsorption, desorption and cooling performance.

If the rotor rotates too quickly, the saturated zeolite section may not remain in the desorption zone long enough to release all adsorbed VOCs. Residual VOC molecules continue occupying the adsorption sites, reducing the removal efficiency when the section returns to the adsorption zone.

If the rotor rotates too slowly, the residence time in the adsorption zone may become excessive, increasing the saturated area and also reducing treatment efficiency.

The optimum rotor speed must therefore be adjusted according to inlet VOC concentration, gas temperature, humidity, desorption temperature and concentration ratio.

For example, under test conditions with an inlet IPA concentration of 200 ppm, an inlet temperature of 25°C, a desorption temperature of 220°C, an inlet humidity of 11 g/kg and a concentration ratio of 13, an optimum rotor speed of approximately 3.3 revolutions per hour was obtained.

2. Concentration Ratio

A lower concentration ratio generally provides higher adsorption efficiency but increases the airflow handled by the downstream oxidation system, which may result in greater fuel consumption.

A higher concentration ratio reduces the downstream airflow but may lower the adsorption efficiency of the rotor.

The concentration ratio should therefore be adjusted to balance VOC removal efficiency, oxidation stability and energy consumption.

3. Desorption Temperature

A suitable desorption temperature provides enough heat to remove VOCs from the zeolite surface and restore adsorption capacity.

However, excessively high desorption temperatures may leave too much residual heat inside the rotor. When the hot rotor section returns to adsorption, the elevated temperature may reduce adsorption performance.

During equipment testing, adsorption efficiency at a desorption temperature of 240°C was lower than at 210°C. This indicated that excessive residual heat inside the zeolite rotor was unfavorable for subsequent adsorption.

The desorption temperature should therefore be selected according to the boiling point, thermal stability and desorption characteristics of the target VOCs.

High-Performance Hydrophobic Zeolite

The system uses hydrophobic molecular sieves with excellent adsorption capacity. This material provides stable treatment performance for a wide range of VOC compounds and changing operating conditions.

Because the zeolite molecular sieve is non-combustible and highly heat-resistant, it can be regenerated at relatively high temperatures. This makes it suitable for some high-boiling-point VOCs that are difficult to treat using adsorption materials with lower regeneration temperature limits.

Hydrophobic zeolite can also effectively treat VOCs with a tendency toward thermal polymerization, including styrene and cyclohexanone, when the system is properly designed and operated.

The concentration rotor is manufactured through high-temperature sintering and consists primarily of inorganic materials. If the honeycomb channels become blocked, the rotor can be cleaned. Depending on its condition, the molecular sieve rotor can also be regenerated through high-temperature activation.

Applicable Industries

• Container painting and coating lines
• Automotive spray-painting workshops
• Aircraft coating and maintenance facilities
• Shipbuilding and marine coating operations
• Furniture painting and finishing lines
• Electronic product coating processes
• Metal product spraying and coating
• Gravure printing workshops
• Flexographic printing lines
• Packaging material printing
• Paint and coating manufacturing
• Semiconductor and integrated circuit manufacturing
• LCD panel manufacturing
• Resin production
• Rubber and tire manufacturing

Typical VOC Applications

Industry	Typical VOC Sources
Spray Painting	Paint solvents, coating vapors, benzene-series compounds, ketones and esters
Printing	Ink solvents, toluene, ethyl acetate, alcohols and mixed VOCs
Electronics	Cleaning solvents, photoresist gases and process VOCs
Semiconductor and LCD	Low-concentration process solvents in high-volume ventilation air
Resin and Rubber	Styrene, cyclohexanone and other organic process emissions
Furniture Manufacturing	Paint, coating, adhesive and drying exhaust gas

Safety and Automatic Control

• PLC-controlled automatic adsorption, desorption and cooling cycles
• Manual operating mode for commissioning and maintenance
• Fire dampers installed in the exhaust gas system
• Multiple temperature monitoring points
• Fan and valve interlock control
• Over-temperature alarm and emergency shutdown protection
• Automatic adjustment of rotor speed and desorption conditions
• Optional VOC concentration and pressure monitoring

Why Choose ES Air Zeolite Rotor Concentrator?

• Customized design for actual VOC composition and airflow conditions
• Efficient concentration of large-volume, low-concentration exhaust gas
• Reduced size and operating load of the downstream oxidation system
• Hydrophobic and non-combustible zeolite molecular sieve material
• Continuous adsorption, desorption and cooling operation
• Heat recovery helps reduce operating energy consumption
• Suitable for a wide range of industrial VOCs
• Compact equipment layout with a relatively small footprint
• Automatic control and multiple safety protection measures

Frequently Asked Questions

What is a zeolite rotor concentrator?

A zeolite rotor concentrator is an industrial VOC treatment system that adsorbs organic compounds from large-volume, low-concentration exhaust gas and transfers them into a smaller-volume, higher-concentration gas stream for oxidation treatment.

What working conditions are suitable for this system?

The system is particularly suitable for high-air-volume, low-concentration VOC exhaust gas generated by painting, printing, electronics, semiconductor, resin and rubber production processes.

What is the typical VOC concentration ratio?

Depending on the exhaust gas characteristics and system configuration, the concentration ratio is generally approximately 5–20 times.

Why is an RTO or RCO installed after the rotor?

The zeolite rotor concentrates VOCs but does not completely destroy them. The concentrated gas must enter an RTO or RCO system, where the organic compounds are oxidized into carbon dioxide and water vapor.

Can the rotor treat high-boiling-point VOCs?

Hydrophobic zeolite can be regenerated at relatively high temperatures and may be suitable for some high-boiling-point VOCs. The feasibility depends on the compound properties, desorption temperature and system design.

Can the zeolite rotor be cleaned?

Yes. If dust or contaminants block the honeycomb channels, the rotor can be cleaned according to the manufacturer’s maintenance procedure. Thermal activation may also be used to restore adsorption performance under suitable conditions.

Can ES Air customize the system?

Yes. ES Air can design the system according to exhaust gas volume, VOC concentration, chemical composition, temperature, humidity, concentration ratio, emission requirements and available installation space.

Customized VOC Concentration and Oxidation Solutions

ES Air provides customized zeolite rotor concentration systems integrated with RTO or RCO oxidation equipment for industrial VOC treatment.

System selection should be based on the exhaust gas composition, airflow, VOC concentration, temperature, humidity, dust and oil mist content, emission pattern and required removal efficiency.

Contact ES Air for working-condition evaluation, process design, equipment selection and customized VOC treatment solutions.

SEO Brief: The ES Air Zeolite Rotor Adsorption and Desorption System concentrates high-volume, low-concentration industrial VOC exhaust gas into a smaller high-concentration stream for RTO or RCO oxidation. Featuring hydrophobic zeolite adsorption, hot-air desorption, cooling regeneration and PLC automatic control, it is suitable for spray painting, printing, electronics, semiconductor, resin, rubber and furniture manufacturing applications.