Application of Activated Carbon Filters in VOC Removal

Volatile Organic Compounds (VOCs) refer to organic chemical substances that readily evaporate at room temperature, including formaldehyde, toluene, xylene, and TVOC. In industrial environments, VOCs may originate from coating processes, printing operations, photoresist and solvent use in semiconductor manufacturing. In general building environments, they primarily come from decorative building materials, furniture adhesives, and cleaning products. Prolonged exposure to high-concentration VOC environments can lead to headaches, respiratory irritation, and even cancer risks.

Activated carbon filters are one of the most widely used technologies for VOC removal. The principle is physical adsorption: activated carbon has an extremely large specific surface area (typically 800-1200 m²/g), and abundant micropore structures effectively capture organic molecules. Key factors affecting adsorption performance include: the carbon material's specific surface area and pore size distribution, contact time (Air Residence Time), pollutant concentration and type, and temperature-humidity conditions.

When selecting filters, the following points require attention: First, the carbon source affects pore size distribution. Coconut shell carbon has a high proportion of micropores, suitable for adsorbing small VOC molecules like formaldehyde; coal-based carbon has higher mesopores, suitable for adsorbing larger molecules like benzene compounds. Second, fill amount directly affects adsorption capacity. The V-shaped activated carbon filters from Baisheng Technology can reach a fill amount of 12-15 kg per sheet, effectively extending service life. Third, contact time must be at least 0.05-0.1 seconds or more; excessive airflow speed reduces adsorption efficiency.

Taking a printed circuit board (PCB) factory as an example, we designed a two-stage activated carbon filtration solution for its exhaust treatment system: the first stage uses granular coal-based carbon filter bed for high-concentration exhaust treatment, the second stage employs coconut shell carbon V-shaped filters for polishing. After system operation, VOC discharge concentration dropped from 120 ppm to below 8 ppm, far below the environmental standard of 60 ppm. For customers with VOC control requirements, Baisheng Technology can provide comprehensive services from airflow calculation, filter selection to system design.