What Are the Manifestations of Catalyst Failure in Catalytic Combustion Equipment?

Catalytic combustion equipment, also known as RCO catalytic oxidation equipment, is widely adopted for industrial VOCs waste gas treatment. The catalyst serves as the core component of the whole system. When catalyst performance declines or fails, the purification efficiency of VOCs will drop sharply, which may cause the whole exhaust treatment system to fail to meet emission standards. Many factory operators cannot quickly identify catalyst failure signs in daily operation, which leads to unexpected shutdown and extra maintenance costs. This article sorts out all typical manifestations of catalytic combustion equipment catalyst failure, analyzes common root causes, and shares practical inspection and maintenance suggestions.

1. Main Manifestations of Catalytic Combustion Equipment Catalyst Failure

1.1 Reduction of VOCs removal efficiency and substandard exhaust emission

This is the most direct signal of catalyst deactivation. Under stable operating conditions, the inlet VOCs concentration remains unchanged, but the outlet VOCs concentration gradually rises. The exhaust gas after treatment may have obvious peculiar smell that cannot be eliminated. Even if operators increase heating temperature or extend retention time, the purification capacity cannot recover to the original level. This phenomenon usually means the active sites on catalyst surface are damaged or covered.

1.2 Abnormal temperature difference before and after catalyst bed

In normal working state, catalytic oxidation reaction releases heat, so the temperature after catalyst bed will be obviously higher than the inlet temperature. When catalyst loses activity, the flameless oxidation reaction of organic waste gas cannot proceed smoothly. The temperature rise across the catalyst bed decreases continuously, and the temperature difference becomes smaller or even disappears. Some users may try to raise the heater set temperature to compensate, which increases energy consumption but cannot improve purification results.

1.3 Increased operating temperature and higher power consumption

Failed catalyst requires higher startup and working temperature to maintain weak reaction. The electric heater will keep working for longer time, and the overall power consumption of the catalytic combustion equipment increases obviously. If the operating temperature exceeds the recommended range for a long time, it will further accelerate catalyst sintering and form a vicious cycle of performance deterioration.

1.4 Visual changes of catalyst carrier

After opening the catalyst chamber for inspection, operators can observe abnormal surface conditions of catalyst monolith:

• Black carbon deposits or coking cover the catalyst surface and block pore channels

• White or gray glaze layer formed by chemical contamination on catalyst surface

• Catalyst carrier cracking, peeling, powdering and shedding of active coating

• Local overheating burns on catalyst surface

1.5 Increased system pressure drop

Coking, dust accumulation and catalyst powdering will block the honeycomb channels of catalyst. The pressure drop of the catalyst bed rises gradually. The blower load increases, the air volume of waste gas delivery becomes unstable, and the overall operation of the VOCs treatment system is affected.

1.6 Unstable operation and frequent abnormal alarms

When catalyst activity is insufficient, the catalytic reaction becomes unstable. The system may trigger temperature abnormal alarms frequently. In serious cases, the equipment cannot maintain stable operation and needs repeated restart. This condition interferes with continuous production of the factory.

2. Comparison Table of Catalyst Working Status

3. Common Causes Leading to Catalyst Deactivation

1. Catalyst poisoning: Sulfur, phosphorus, silicon, halogen and heavy metal substances in waste gas cover active components and cause permanent activity loss.

2. High-temperature sintering: Long-time ultra-temperature operation leads to the sintering of active metal particles and the collapse of carrier pore structure.

3. Coking and fouling: Dust, tar and polymer organic matter block catalyst channels and cover active sites.

4. Mechanical damage: Vibration, thermal shock and improper disassembly cause carrier breakage and washcoat loss.

5. Hydrothermal aging: Long-term impact of water vapor under high temperature changes the physical structure of catalyst carrier.

4. How to Diagnose and Deal With Catalyst Failure

When multiple above-mentioned symptoms appear at the same time, users should carry out systematic inspection step by step, instead of directly replacing the catalyst blindly. First, check sensors, heating components, pipeline leakage and fan operating status to rule out equipment fault interference. After confirming that the auxiliary parts are normal, evaluate the catalyst condition and decide regeneration or replacement scheme.

Zhengzhou Puhua Technology is an environmental protection equipment manufacturer located in Henan. The company focuses on the design, research, development and production of dust control equipment, desulfurization equipment, denitrification equipment, VOCs organic waste gas treatment equipment, pneumatic conveying equipment and sewage treatment equipment. Its product portfolio includes baghouse dust collectors, RCO catalytic combustion equipment, RTO equipment, VOCs treatment equipment, desulfurization towers, denitrification equipment, photo-oxygen catalytic equipment, pulse dust collectors, mobile dust collectors, ultra-low emission equipment and sewage treatment equipment. For customers running catalytic combustion systems, Zhengzhou Puhua Technology provides technical guidance on routine catalyst inspection, system maintenance and equipment operation optimization, helping industrial users extend catalyst service life and keep exhaust gas treatment systems running steadily.

5. Routine Maintenance Suggestions to Slow Down Catalyst Deactivation

• Install pre-treatment facilities to remove particulate matter, tar and toxic substances before waste gas enters catalytic combustion equipment.

• Strictly control the operating temperature of RCO equipment to avoid long-time over-temperature operation.

• Monitor inlet gas composition regularly and avoid waste gas containing catalyst poisons entering the reaction chamber.

• Carry out periodic inspection of catalyst bed pressure drop and temperature data, record operation parameters for trend analysis.

• Follow the equipment operation manual for shutdown and startup procedures to reduce thermal shock to catalyst carrier.

Conclusion

Catalyst failure of catalytic combustion equipment will not occur suddenly. A series of measurable changes on exhaust quality, temperature, pressure drop and power consumption will appear in advance. Factory operators should master these typical manifestations, establish regular operation record mechanism, and discover hidden troubles at an early stage. Reasonable pre-treatment and standardized operation can effectively delay catalyst aging, reduce replacement frequency and control the operation cost of VOCs governance system. If you need professional technical support for RCO catalytic combustion equipment operation and maintenance, you can consult the technical team of Zhengzhou Puhua Technology for targeted suggestions.