Niche Applications of Blowers in Industrial Waste Gas Treatment and VOCs Abatement

Introduction

Industrial waste gas treatment is the core battleground in atmospheric pollution prevention and control, and volatile organic compounds (VOCs), as key precursors to PM2.5 and ozone formation, have become a top priority in current environmental governance. Within this extensive governance framework, Blower It serves as the “industrial heart”—not only providing the power needed for exhaust gas collection and conveyance, but also offering critical support that enables various purification processes to operate efficiently. By 2025, China’s VOCs control market had already reached approximately RMB 115 billion, and by 2026, the country’s industrial exhaust gas treatment market is expected to surpass RMB 250 billion. On this multi‑hundred‑billion‑yuan growth trajectory, every technological advancement in blower technology profoundly shapes both treatment efficiency and operational costs.

I. Overview of VOCs Control Technologies and the Role of Blowers

The mainstream technological approaches for VOCs control primarily encompass four major categories: adsorption, combustion (including RTO/RCO), biological treatment, and condensation. Regardless of the specific process, blowers are indispensable core equipment.

• Adsorption method : VOCs are captured using adsorbents such as activated carbon and molecular sieves. A blower supplies a continuous, stable negative-pressure airflow to the adsorption unit, conveying the VOCs into the adsorption vessel. During desorption and regeneration, additional energy is required to deliver hot air or steam.
• Regenerative Thermal Oxidation (RTO)/Regenerative Catalytic Oxidation (RCO) : VOCs are decomposed into CO₂ and H₂O via high-temperature oxidation, with the blower supplying combustion-supporting air or recirculated air to the regenerative thermal oxidizer.
• Biological method : Microbial degradation of VOCs relies primarily on the aeration system’s blowers for energy consumption.
• Condensation method : VOCs are liquefied and recovered through cooling, while a blower is used for gas circulation and transport within the system.

The performance requirements for blowers vary significantly across different processes: RTO systems demand medium-to-high pressure and large air volumes, biological treatment methods require low pressure with high flow rates, and adsorption processes necessitate stable negative-pressure suction. This diversity of technologies has given rise to multiple specialized market segments for blowers in the VOCs abatement sector.

II. Types of Blowers and Technological Evolution

1. Traditional Roots blower

Roots blowers are positive-displacement fans that convey gas by rotating two figure‑eight‑shaped rotors within a cylinder. Their advantages include a simple, reliable design, low capital costs, and a wide pressure range. However, their drawbacks are equally significant: efficiency ranges only from 50% to 70%, noise levels can reach 85–110 dB, and there is a risk of mechanical friction and lubricant leakage. In VOCs control applications, oil‑mist emissions not only increase maintenance expenses but may also contaminate catalysts or biological cultures, thereby compromising treatment performance.

2. Centrifugal Blower

Centrifugal blowers convert kinetic energy into pressure energy by means of the high-speed rotation of an impeller. In VOCs treatment, Backward-curved impeller centrifugal fan It is the mainstream choice—achieving efficiencies of 85% or higher, with low noise levels, and suitable for medium- to high-pressure, high-flow systems. The inlet and outlet airflow directions are at a 90° angle; therefore, centrifugal fans should be prioritized over axial fans in VOCs treatment facilities. In terms of materials, for standard VOCs control applications, it is recommended to use 316L stainless steel fans paired with Ex d IIB T4 explosion-proof motors.

3. Magnetic Levitation Centrifugal Blower

This is the most rapidly advancing, high-efficiency, energy-saving technology pathway in recent years. Magnetic‑levitation blowers employ active magnetic bearings and high‑speed permanent‑magnet synchronous motors, achieving fully suspended, contactless operation of the rotor shaft. Their key advantages include:

• High efficiency and energy saving : The fan efficiency can exceed 85%, with energy consumption reduced by 30% to 40% compared to conventional Roots blowers.
• Precise regulation : Variable-frequency speed control enables stepless adjustment of airflow within the range of 45% to 100%.
• Clean and oil-free : Oil-free design, eliminating secondary contamination.
• Low noise : Operating noise can be reduced to below 80 dB.

4. Side-channel (side-blow) blower

The side-channel blower features a unique flow path with axial air intake and lateral air discharge, resulting in a compact design that reduces its footprint by up to 30% compared to centrifugal blowers of the same power rating. It delivers a total pressure efficiency exceeding 82% and operates at noise levels ≤75 dB. This model is particularly well-suited for VOC abatement applications where space is limited, such as compact RTO units or modular activated carbon adsorption systems.

5. Flameproof Ring Blower

For exhaust gas treatment applications involving flammable and explosive VOCs such as benzene and methanol, explosion-proof ring blowers ensure safe operation through designs including an explosion-proof enclosure, an antistatic impeller, and an explosion-proof motor. In VOC control systems for painting workshops, they can achieve a waste gas collection efficiency of 95% or higher.

III. In-depth Analysis of Core Process Scenarios

(1) RTO/RCO Systems: The Core Driving Force Behind Combustion Air and Recirculation Air

RTO (Regenerative Thermal Oxidation) is currently the mainstream technology for treating large‑volume, medium‑to‑low‑concentration VOCs. In an RTO system, the blower performs two primary functions: first, it supplies combustion air to the combustion chamber to ensure complete oxidation of VOCs; second, it provides recirculating air to maintain efficient heat transfer within the heat‑storage media.

In an RTO system, fan selection must give priority to the following considerations: Matching Total Pressure and Airflow 、 Explosion-proof performance and also Reliability under high-temperature operating conditions . Since VOC concentrations may exceed 25% of the lower explosive limit (LEL), the fan must be equipped with a comprehensive explosion-proof configuration. The motor is typically of the flameproof type, and the fan housing must undergo spark‑free treatment.

Technology Trends Magnetic‑levitation centrifugal blowers are rapidly replacing traditional Roots blowers in RTO/RCO systems. Their variable‑frequency speed‑control capability precisely matches the airflow fluctuations caused by the periodic reversing cycles of RTO furnaces, while their intelligent control system dynamically optimizes energy consumption in response to changes in exhaust gas concentration. For example, in a VOCs abatement project at a chemical industrial park, replacing a Roots blower with a magnetic‑levitation centrifugal blower improved overall energy efficiency by more than 35% and reduced noise levels from above 95 dB to below 80 dB.

(2) Activated Carbon Adsorption/Desorption System: Negative-Pressure Collection and Regeneration Conveyance

Activated carbon adsorption is suitable for the treatment of medium- and low-concentration VOCs and for solvent recovery. The blower plays a dual role in this process:

• Adsorption stage : Provides a continuous and stable negative pressure to collect fugitive VOC emissions from the workshop and convey them to an activated carbon adsorption unit. For uncontrolled emissions in industries such as coating and printing, the collection efficiency can exceed 95%.
• Desorption and Regeneration Stage : Provides the driving force for conveying hot air or steam, desorbing VOCs from the saturated activated carbon and directing them to the downstream condensation or combustion unit.

Key Considerations for Selection : VOCs treatment facilities should use centrifugal fans and must not employ axial fans. The main fan parameters include airflow rate (m³/h), static pressure (Pa), rotational speed, power consumption, and noise levels. For exhaust gases containing corrosive components (such as chlorobenzene and hydrogen sulfide), stainless steel (304/316L) must be selected, with a temperature resistance of up to 400°C.

(3) Biofilter/Bio-trickling filter systems: the core equipment for aeration and oxygen supply

The biological method uses microorganisms to degrade VOCs—treated as “food”—into CO₂ and H₂O, offering advantages such as operation at ambient temperature and pressure, no need for fuels or catalysts, and simple maintenance. The primary energy consumption stems from the blowers in the aeration system.

The requirements for blowers in biological treatment are High airflow, low pressure, continuous and stable operation Magnetic‑levitation blowers offer distinct advantages in this application, thanks to their precise oxygen‑supply control and low‑maintenance design. In VOCs‑biological treatment units at wastewater‑treatment plants within chemical parks, the adoption of magnetic‑levitation blowers can reduce aeration‑system energy consumption by 42%. Intelligent control strategies dynamically adjust blower operating frequencies in real time based on fluctuations in pollutant concentrations, enabling “precise collection and demand‑driven delivery.”

(4) Synergistic Sulfur and Nitrogen Oxide Removal: Gas Transport in Multiple Scenarios

In industrial flue-gas treatment, desulfurization and denitrification systems are closely linked to VOC control—many chemical and petrochemical plants must simultaneously treat SO₂, NOx, and VOCs in their exhaust gases. Blowers are used in the following application scenarios:

• Desulfurization system : Supplies air to the absorption tower to oxidize calcium sulfite into gypsum.
• SCR denitrification system : Conveys diluted air and ensures uniform mixing of ammonia solution/urea with flue gas.

The oil-free, clean-gas characteristics of magnetic‑levitation blowers are particularly critical here, as they help prevent catalyst poisoning and product contamination. At a chemical plant in Yunnan, replacing four 250 kW Roots blowers with two 300 kW magnetic‑levitation blowers resulted in average daily energy savings of approximately 2,641 kWh, achieving an energy‑saving rate of 51% and reducing noise levels from 120 dB to below 80 dB.

IV. Selection Guide: From Technical Specifications to Full Lifecycle Considerations

1. Fan Type Selection

2. Explosion Protection and Safety

VOCs are predominantly flammable and explosive substances, so explosion-proof safety must be the top priority when selecting fans. In typical VOCs treatment applications, the following are selected: Ex d IIB T4 Flameproof motors can meet the requirements; for highly hazardous gases such as hydrogen and acetylene, an upgrade to… is required. Ex d IICT6 The impeller and the main shaft shall be made of conductive materials (such as stainless steel), with a grounding resistance not exceeding 4 Ω.

3. Material and Corrosion Protection

The corrosivity of the exhaust gas components is a key criterion in equipment selection.

• Carbon steel : Non-corrosive, ambient-temperature exhaust gas; a corrosion-resistant coating is required.
• Stainless steel (304/316L) : Resistant to acids, alkalis, and salt spray, with a temperature resistance of up to 400°C, making it the preferred choice for VOCs treatment.
• Fiberglass Reinforced Plastic (FRP) : Resistant to strong acids; maximum operating temperature 80°C.
• PP/PVDF : Highly corrosive environments (such as electroplating acid mist)

4. Intelligent Control and Energy Efficiency

Variable-frequency drive (VFD) control has become the standard configuration for VOC‑control blowers. By adjusting the rotational speed to keep the blower operating in its high‑efficiency range, the “over‑sizing” phenomenon is avoided, resulting in overall energy savings of 20% to 40%. Even more advanced… Intelligent Interconnected Control System By integrating an airflow sensor, a VOCs concentration analyzer, and a variable-frequency drive control cabinet, the system achieves coordinated optimization between the fan and the combustion system. The “High-Efficiency, Low‑Consumption Exhaust Gas Collection and Distribution Technology” developed by the Tsinghua Suzhou Environmental Innovation Research Institute employs high‑precision sensing probes—monitoring hydrogen sulfide, airflow, pipeline pressure, and other parameters—along with fan operating data to establish an adaptive, adjustable intelligent control strategy for the fan.

V. Industry Trends and Future Outlook

1. The market size continues to expand.

The global environmental‑friendly fan market reached approximately US$18.6 billion in 2025 and is projected to surpass US$34 billion by 2030, with a compound annual growth rate of 12.8%. In China, the environmental‑friendly fan industry is expected to generate an output value of roughly RMB 68 billion in 2025. As a specialized segment, exhaust‑gas treatment fans are forecast to account for a global market size of about US$4.117 billion in 2025.

2. High-efficiency, energy-saving technologies are accelerating their penetration.

Magnetic‑levitation and air‑bearing centrifugal blowers are reshaping the industry landscape. Compared with conventional roots blowers, magnetic‑levitation blowers deliver 30%–50% energy savings, reduce noise by 20–30 dB, and require virtually no maintenance. Although the upfront capital cost is higher, their total lifecycle cost advantages are substantial—typically recouping the initial investment differential through electricity‑cost savings within 2 to 3 years.

3. Intelligence and digitalization have become standard features.

The shift from providing standalone equipment to offering system‑level solutions that integrate “equipment + intelligent control + cloud platform” has become the industry’s prevailing trend. Digital capabilities such as multi‑parameter feedback control, predictive maintenance, and remote operations and maintenance are increasingly emerging as core competitive advantages for blower manufacturers.

4. Policy-driven support continues to be strengthened.

The Environmental Protection Tax Law of the People’s Republic of China has expanded the scope of VOC taxation, with potential coverage extending to more than 300 VOC pollutants in the future. The Ministry of Ecology and Environment has so far supported over 100 “Green Island” VOC‑related projects, providing approximately RMB 880 million in funding. Driven by the dual carbon goals, the coordinated advancement of VOC control and energy conservation–carbon reduction will create broader market opportunities for high‑efficiency blower technologies.

Conclusion

The application of blowers in industrial exhaust gas treatment and VOCs abatement has long transcended their traditional role as mere air‑supply devices, instead becoming deeply integrated into the core stages of diverse treatment processes such as adsorption, combustion, and biological degradation. From Roots to centrifugal designs, and from magnetic‑levitation to air‑bearing technologies, each technological advancement is redefining the industry’s energy‑efficiency limits and operational paradigms. For environmental engineering firms and end users alike, a thorough understanding of the characteristics and application boundaries of different blower technologies—coupled with informed equipment selection and intelligent operation and maintenance—is essential to striking an optimal balance between increasingly stringent environmental regulations and steadily rising energy costs. This is not merely a technical challenge in equipment selection; it is a strategic imperative in the era of green, low‑carbon transformation.