A VOC catalytic oxidation system is used to treat organic waste gas containing suitable volatile organic compounds. Under controlled operating conditions, a catalyst helps promote the oxidation reaction at a lower temperature than direct thermal oxidation. The process converts suitable organic compounds primarily into carbon dioxide and water.

VOC catalytic oxidation is an exhaust-gas treatment method, not a dust collection method. Before selecting equipment, the VOC composition, concentration, airflow, temperature, moisture content and possible catalyst contaminants should be evaluated.

How Does VOC Catalytic Oxidation Work?

Organic waste gas enters the catalytic oxidation system and is heated to the required reaction temperature. The gas then passes through the catalyst bed, where suitable VOC components are oxidized. A heat exchanger may be used to recover heat from the treated gas and reduce the energy required for operation.

The actual reaction temperature, energy demand and treatment performance depend on the VOC composition, inlet concentration, airflow stability and catalyst condition. Proper upstream filtration or pretreatment may be required where the exhaust contains dust, oil mist, corrosive substances or catalyst-poisoning compounds.

1. Preheating Catalytic Oxidation

Preheating catalytic oxidation is commonly considered when the inlet gas has a relatively low VOC concentration or low temperature. An electric heater, gas heater or other heat source raises the exhaust gas to the required reaction temperature before it enters the catalyst bed.

Heat recovery from the treated gas can improve overall energy efficiency. The suitable heating method should be selected according to the airflow, VOC characteristics and project requirements.

2. Self-Sustaining Catalytic Oxidation

When the organic concentration and thermal value of the exhaust gas are sufficient, heat released during oxidation may support part or all of the required reaction heat after start-up. Whether a system can operate in thermal balance must be evaluated from the actual VOC composition, concentration and airflow conditions.

Start-up heating and operating controls are still normally required to maintain stable and safe process conditions.

3. Adsorption Concentration with Catalytic Oxidation

For large airflow with low VOC concentration, an adsorption concentration process may be considered. The VOCs are first adsorbed and concentrated, then desorbed into a smaller-volume, higher-concentration gas stream for catalytic oxidation.

This configuration can reduce the size of the downstream oxidation process in suitable applications. Adsorbent selection, desorption conditions and operating controls should be designed according to the actual exhaust composition.

VOC Treatment System Selection

The correct industrial exhaust treatment equipment should be selected according to the production process and emission requirements. Important selection factors include VOC type, airflow, concentration, temperature, moisture, dust loading, operating schedule and available utility conditions.

Jiangsu Erhuan Environmental Technology Co., Ltd.