The activated carbon rotary kiln is a key piece of equipment used in the high-temperature carbonization and activation stages of activated carbon production. Through continuous mechanized operations, it converts carbon-containing raw materials such as coal and wood into highly adsorbent activated carbon products. Its core function is to achieve pyrolysis of the material under high-temperature conditions. It is widely used in environmental protection, chemical engineering, food processing, gold extraction, and other fields for water purification, decolorization, and purification, as well as waste gas treatment.

Activated carbon is a porous carbon material with a highly developed surface area and excellent adsorption performance. It is widely used in environmental protection, chemical processing, metallurgy, food, pharmaceuticals, and renewable energy. In the manufacturing process, the rotary kiln plays a central role as the main thermal treatment equipment.

The Rotary Kiln for Activated Carbon Production is specifically designed for carbonization and activation of raw materials such as wood, coconut shell, palm shell, coal, and biomass residues. It enables continuous heating, carbonization, and activation, ensuring the desired pore structure and adsorption capacity of activated carbon. Therefore, it has become the core equipment in modern activated carbon production lines.

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Structure of Activated Carbon Rotary Kiln

A typical activated carbon rotary kiln consists of the following major components:

1. Kiln Shell
   • Cylindrical steel structure lined with refractory bricks or ceramic fiber.
   • Supported by rollers and driven by girth gear to rotate slowly.
2. Driving Device
   • Consists of motor, reducer, and gear transmission.
   • Provides stable low-speed rotation, adjustable through frequency control to suit various raw materials.
3. Burner System
   • Can use coal gas, natural gas, heavy oil, or electric heating as energy sources.
   • Delivers heat uniformly inside the kiln through specialized burners.
4. Feeding and Discharging System
   • Continuous feeding devices at the kiln inlet.
   • Cooling unit or cooler installed at the outlet to rapidly reduce activated carbon temperature.
5. Sealing and Dust Removal System
   • Sealed kiln head and tail to prevent air leakage.
   • Equipped with bag filter or wet scrubber to ensure emission compliance.

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Working Principle of Rotary Kiln for Activated Carbon Production

The operation of an activated carbon rotary kiln involves two main stages:

1. Carbonization Stage

• Raw materials (coconut shell, wood chips, coal, palm shell, etc.) are heated to 400–700°C under oxygen-deficient or inert conditions.
• Volatile matter is released, and the initial carbonized material with a basic pore structure is formed.

2. Activation Stage

• The carbonized material is subjected to 800–1000°C with steam or carbon dioxide.
• Key reactions include:
  • C + H2O → CO + H2
  • C + CO2 → 2CO
• These reactions etch the carbon surface, developing abundant micropores and mesopores, significantly increasing surface area.

The slow rotation of the activated carbon rotary kiln ensures uniform heat distribution and sufficient contact with activation gases, resulting in high-quality activated carbon.

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Advantages of Activated Carbon Rotary Kiln

1. Continuous Production

• Compared with batch carbonization furnaces, rotary kilns achieve large-scale continuous operation.
• Suitable for industrial plants with annual output exceeding thousands of tons.

2. High Efficiency and Output

• Customizable kiln diameter (1.5–3.5m) and length (20–50m).
• Controllable residence time ensures sufficient activation and high yield.

3. Stable Product Quality

• Uniform temperature distribution ensures consistent carbonization and activation.
• Activated carbon surface area can reach 800–1500 m²/g, meeting industrial standards.

4. Energy Saving and Eco-Friendly

• Waste heat recovery system reduces fuel consumption by 15–20%.
• Equipped with dust collectors and gas treatment systems to meet environmental standards.

5. Wide Applicability

• Suitable for coconut shell, palm shell, bamboo, sawdust, coal, petroleum coke, and more.
• Produces powder activated carbon, granular activated carbon, and pellet activated carbon.

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Applications of Activated Carbon Rotary Kiln

1. Water Treatment
   • Drinking water purification
   • Wastewater treatment
   • Industrial effluent decolorization and adsorption
2. Air Purification
   • Industrial exhaust gas treatment
   • Indoor air purification
   • Automotive emission control
3. Chemical Industry
   • Catalyst support
   • Solvent recovery
   • Gas purification
4. Food and Pharmaceutical
   • Pharmaceutical decolorization
   • Food processing purification
   • Beverage and alcohol filtration
5. New Energy Sector
   • Lithium battery electrode materials
   • Supercapacitor carbon materials
   • Hydrogen storage and methane adsorption

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Process Flow of Activated Carbon Production Rotary Kiln

1. Raw Material Preparation
   • Coconut shell, sawdust, palm shell, or coal undergoes crushing, screening, and drying.
2. Carbonization
   • Material enters rotary kiln under oxygen-limited conditions, forming char.
3. Activation
   • Char reacts with steam/CO2 at high temperature, forming porous structure.
4. Cooling and Discharging
   • Activated carbon is cooled rapidly to avoid spontaneous combustion.
5. Screening and Packaging
   • Final products are graded into powdered, granular, or pellet forms, then packed.

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Comparison with Other Furnaces

Furnace Type	Features	Application Scope	Disadvantages
Rotary Kiln	Continuous, high output, stable quality	Large-scale industrial production	Higher investment cost
Vertical Kiln	Compact, high thermal efficiency	Medium-scale production	Limited automation, less flexibility
Batch Carbonization Furnace	Low cost, simple design	Small-scale, household or pilot use	Low yield, unstable quality