Activated Carbon for Solvent Recovery

Solvent recovery activated carbon is a high-performance adsorption material specially used for recovering organic solvents from gas or liquid phase. It has a developed pore structure, high adsorption capacity and excellent desorption performance. It is widely used in chemical, pharmaceutical, printing, electronics and other industries to reduce solvent loss, reduce waste gas emissions and protect the environment.

Characteristics of solvent recovery activated carbon

1. High specific surface area and pore structure

- It has a large number of micropores and mesopores, which can effectively adsorb organic solvent molecules.

- The specific surface area is usually greater than 1000 m²/g, providing abundant adsorption sites.

2. Excellent adsorption and desorption performance

- It has good adsorption capacity for solvent molecules and fast desorption rate, which is conducive to efficient recovery of solvents.

3. High mechanical strength and wear resistance

- The activated carbon particles are not easy to break or pulverize, and are suitable for long-term recycling.

4. Strong chemical corrosion resistance

- It can resist corrosion from a variety of organic solvents and maintain structural stability.

5. Good thermal stability
- It can maintain performance under high temperature conditions and adapt to the thermal desorption process.

Adsorption principle of activated carbon for solvent recovery
1. Physical adsorption
- Activated carbon produces van der Waals force adsorption on solvent molecules through its developed micropores and mesopores.
- Solvent molecules enter the pores of activated carbon at room temperature and are fixed.
2. Desorption principle
- Under high temperature or low pressure conditions, solvent molecules are released from the pores of activated carbon to achieve solvent recovery.
- Hot air desorption, water vapor desorption or vacuum desorption are common methods.

Applicable solvent types

1. Volatile organic solvents (VOCs)
- Aromatic solvents such as toluene, xylene, styrene, and cyclohexanone.
- Alcohol solvents such as acetone, isopropanol, ethanol, and methanol.

2. Halogenated hydrocarbon solvents
- Trichloroethylene, tetrachloroethylene, dichloromethane, chloroform, etc.
3. Aliphatic hydrocarbon solvents
- n-hexane, n-heptane, isooctane, etc.
4. Other solvents
- diethyl ether, ketones, ester solvents, etc.

Solvent recovery process and the role of activated carbon

1. Adsorption recovery process
- The waste gas or waste liquid containing solvent passes through the adsorption bed equipped with activated carbon, the solvent molecules are adsorbed by the activated carbon, and the purified gas or liquid is discharged.

2. Desorption regeneration process
- The adsorption saturated activated carbon is desorbed by heating, steam or vacuum treatment, and the solvent is collected for reuse.

3. Condensation recovery process
- The desorbed solvent is cooled and recovered by the condenser, converted into liquid and reused.

Process characteristics of activated carbon for solvent recovery

1. Fixed bed adsorption device
- Suitable for solvent recovery in gas, usually using multiple adsorption towers to work alternately (adsorption, desorption, cooling) to achieve continuous operation.

2. Fluidized bed adsorption device
- Utilize the fluidization characteristics of activated carbon particles to increase the adsorption and desorption efficiency.
3. Rotary adsorption device
- Loading activated carbon on the rotor, the exhaust gas is adsorbed and desorbed through the rotor, which is one of the efficient solvent recovery technologies.

Advantages and limitations

Advantages
- High recovery efficiency: the solvent recovery rate can reach more than 90%, reducing production costs.
- Significant environmental benefits: reducing organic solvent emissions, meeting environmental protection requirements.
- Strong renewability: activated carbon can be recycled after regeneration, reducing operating costs.
Limitations
- High initial investment: high-performance activated carbon and equipment costs are high.
- Strict operating conditions: the temperature, pressure and other parameters of adsorption and desorption need to be controlled.
- Not suitable for some highly polar or high boiling point solvents: the adsorption and desorption efficiency of these solvents may be low.

Selection and use suggestions

1. Select activated carbon according to solvent characteristics
- For polar solvents or macromolecular solvents, activated carbon with specific pore size and surface functional groups should be selected.
2. Regular maintenance and regeneration
- Regularly check the adsorption saturation and desorb or replace the activated carbon in time.
3. Optimize operating conditions
- Control the adsorption temperature (usually room temperature), the desorption temperature is usually 100-150℃.
4. Prevent overheating or clogging of the adsorption bed
- Install a temperature monitoring system to avoid the risk of fire caused by excessive solvent concentration or excessive aging of activated carbon.

Summary
Solvent recovery activated carbon is an important material for resource recycling and waste gas treatment. Its high efficiency, economy and environmental protection make it a core tool in the field of industrial solvent recovery. In specific applications, appropriate activated carbon and process flow should be selected according to the type and concentration of the solvent and equipment conditions to achieve the best economic and environmental benefits.

If you need to customize solvent recovery activated carbon or optimize the recovery system design, please feel free to contact us!