Resin Adsorption for VOCs Treatment

Volatile Organic Compounds (VOCs) are a group of organic compounds that easily vaporize at room temperature, including hydrocarbons, alcohols, ketones, and others. VOCs are common in industrial production and daily life, and they can react with oxidants in the air to form photochemical smog, posing risks to the environment and human health. As environmental regulations become stricter, industries are seeking effective VOC control and treatment solutions. Among various treatment methods, resin adsorption technology has gained popularity due to its high efficiency, selectivity, and ability to recycle VOCs.

We have developed a resin adsorption technology in VOCs treatment not only for meeting emission compliance, but also for the recovery of solvents including: alkanes, halogenated hydrocarbons, aromatic hydrocarbons, low-carbon alcohols, ketones, esters, and other organic matters.

Our adsorption technology for VOCs treatment is mainly used for non-polar and weakly polar volatile organic molecules. It adopts a specifically developed macroporous polymer adsorption resin with uniform pore size, high specific surface area and high strength. By utilizing the non-polar adsorption and intermolecular forces between the internal skeleton molecules of the resin and the volatile organic molecules, the adsorption resin performs highly selective adsorption on the non-polar and weakly polar molecular groups in the waste gas, in order to achieve the purpose of precise adsorption, recovery and gas emission compliance.

• CT-10

The typical process of VOCs emission treatment involves the following steps:

1. Gas Collection and Pre-treatment: After collecting the waste gas, it is pre-treated to remove particulates and moisture, which can impact adsorption efficiency.
2. Resin Adsorption: The pre-treated gas passes through a resin bed where VOCs are adsorbed, effectively reducing VOC concentrations, and cleaned gas is emitted from the outlet.
   • Working Principle
     The primary mechanism for resin adsorption is physical adsorption, which involves van der Waals forces, hydrogen bonding, and other intermolecular interactions to capture VOCs on the resin surface. The desorption process can then release the VOCs through heating or solvent dissolution.
   • Reaction For example, the adsorption process of toluene (C₆H₅CH₃) adsorption can be represented as:
     C₆H₅CH₃(gas) + Resin → C₆H₅CH₃(adsorbed state)
     In that:
     • C₆H₅CH₃: Represents a toluene molecule, consisting of a benzene ring (C₆H₆) and a methyl group (CH₃), commonly found in industrial waste gases
     • Resin: Provides the porous surface structure that captures toluene and other VOCs
   • Resin Regeneration: When the resin reaches adsorption saturation, it undergoes thermal or solvent desorption to release the adsorbed VOCs for recovery.
   • VOCs Recovery and Treatment: The desorbed VOCs are collected and further treated or recycled as usable chemicals or energy sources.

Industry

• Chemical Industry. Solvent recovery and separation, such as benzene, toluene, and xylene recovery.
• Printing Industry. Reduce VOC emissions from ink and solvent evaporation.
• Pharmaceutical Industry. Recovery of organic solvents like ethanol and acetone to meet emission standards and reduce costs.
• Petrochemical Industry. Recover hydrocarbons from refining processes and chemical production.
• Electronics Industry. Recycle and treat VOC emissions from electronics manufacturing and packaging.

Typical Applications

• Alkanes and Cycloalkanes. N-Hexane, Heptane, Cyclohexane
• Halogenated Hydrocarbons. Trichloroethylene, Trichloroethane, Dichloromethane, Trichloromethane (Chloroform), Chlorobenzene
• Aromatic Hydrocarbons. Benzene, Toluene, Xylene (BTX compounds)
• Alcohols. Isopropanol (IPA), Butanol
• Ketones. Acetone, Butanone (Methyl Ethyl Ketone, MEK), Methyl Isobutyl Ketone (MIBK), Cyclohexanone
• Esters. Ethyl Acetate, Butyl Acetate, Acetic Acid Esters

Current Challenges in VOCs Treatment

• Insufficient Efficiency: Traditional VOC treatment methods, such as condensation and combustion, are often ineffective for low-concentration, complex VOCs, frequently requiring multi-stage treatments that increase energy consumption.
• Resource Wastage: Many VOCs can be recycled as solvents or chemical raw materials, but traditional methods are often incapable of effective recovery, leading to waste.
• High Operational and Maintenance Costs: Some physical or chemical methods, such as catalytic combustion, are efficient but require high temperatures, making the systems complex and costly to maintain.
• Stringent Environmental Regulations: With increasingly stringent standards, industries face higher demands for VOC control equipment to meet lower emission limits.

Advantages of Resin Adsorption Technology

Resin adsorption technology offers several advantages in VOCs treatment due to its strong adsorption capacity and recyclability:

• Flexibility: multiple resin options can adapt to different industries and different systems from small equipment, skid-mounted equipment, to waste gas treatment system. Flexible cooperation to meet emission requirements.
• Strength: regular spherical particles with acid, alkali and high-temperature resistance, over 2000 regeneration cycles.
• Purity: Synthetic styrene structure that has no metal impurities, preventing catalytic polymerization or combustion of unsaturated organics in pores.
• Efficiency: Over 99.5% removal rate for non-polar and weakly polar VOCs, for emission compliance.
• Security: Good hydrophobicity. Thanks to its own water content, no need for dry adsorption, avoiding sustained heating due to adsorption exotherm.
• Sustainability: Longer life cycle, no need for overall replacement, no solid waste generation. Annual replenish around 5%.