How to Extend the Lifespan of a Catalyst in Treating Carbon Monoxide in Industrial Waste Gas?

Carbon monoxide (CO) in industrial waste gas is a typical toxic pollutant. Catalysts convert it into harmless carbon dioxide (CO₂) through catalytic oxidation, a core technology for achieving environmentally compliant emissions. Commonly used catalysts include platinum-palladium precious metal catalysts and copper-manganese oxide catalysts. Within an activity window of 200-600℃, they can efficiently catalyze the reaction of CO and oxygen, achieving a purification efficiency of over 95%. However, catalysts are prone to failure due to poisoning and carbon buildup. Extending their lifespan requires scientific management of the entire process.

Key Considerations for Industrial Waste Gas Treatment: 

Two key points must be controlled before treatment: First, waste gas pretreatment is crucial to prevent toxic substances such as sulfur and chlorine, as well as dust, from entering the catalytic system. These impurities directly damage active sites. Second, stable reaction conditions are essential. The temperature must be controlled within the active window, and the excess oxygen coefficient must be maintained at 1.2-1.5 to prevent carbon buildup or sintering. Data from a chemical company shows that without pretreatment, the catalyst lifespan is only 1.5 years, but after pretreatment, it is extended to over 3 years.

Key Methods for Extending Catalyst Lifespan:

 First, precise pretreatment is essential for hazard removal. Installing desulfurization towers, activated carbon dechlorination devices, and bag filters can reduce sulfur content to <0.1ppm and dust concentration to below 10mg/m³, reducing the risk of chemical poisoning by over 80%. Secondly, reaction parameters were optimized. An intelligent temperature control system was used to keep hotspot temperature fluctuations within ±20℃, preventing platinum particle agglomeration and sintering. Adjusting the airflow distribution reduced carbon buildup.

Regular regeneration and dynamic monitoring are equally important. Every 3-6 months, high-temperature air at 300-500℃ was introduced to oxidize carbon deposits, restoring 70% of slightly deactivated activity. Online monitoring of the outlet CO concentration (compliant value <50ppm) and bed pressure drop was conducted, and local replacement was performed promptly when the purification efficiency fell below 80%. Furthermore, a honeycomb cordierite carrier catalyst was selected, increasing mechanical strength by 40% and significantly enhancing wear resistance.

A steel plant's sintering waste gas treatment project originally used granular catalysts with a lifespan of only 2 years and a CO treatment capacity of 5000 m³/h. After optimization, a desulfurization and dust removal pretreatment system was added, using a cerium-zirconium-doped palladium-based honeycomb catalyst. Combined with intelligent temperature control and quarterly regeneration, the catalyst lifespan was extended to 4.5 years, and the treatment cost decreased from 12 yuan/thousand cubic meters to 8.5 yuan/thousand cubic meters. The outlet CO concentration remained stable below 30 ppm, meeting the GB 16297 emission standard.

In summary, through a full-chain management approach of "pretreatment and pest control + parameter optimization + regeneration monitoring," the lifespan of carbon monoxide catalysts can be significantly extended, balancing environmental benefits and economic efficiency.

Author: Hazel
Date: 2025-11-13