Pyrolysis Tube Furnace is a type of high-temperature equipment designed for the thermal decomposition of materials in an inert atmosphere. It is widely used in laboratories and industrial research centers for carbonization, catalyst preparation, and material synthesis. This furnace enables precise control of temperature, atmosphere, and heating rate, making it ideal for applications involving organic and inorganic material transformation.

Working Principle

The pyrolysis tube furnace operates by heating materials inside a sealed tube—usually made of quartz, alumina, or stainless steel—under a controlled gas flow such as nitrogen, argon, or hydrogen. When the sample is exposed to high temperatures (typically between 300°C and 1200°C), it undergoes thermal decomposition, breaking down complex molecules into simpler gases, liquids, and solid residues (char).

This process is fundamental in the production of biochar, activated carbon, carbon nanotubes, and in studying the thermal behavior of polymers and biomass.

Structural Features

1. Heating Elements:
   Most pyrolysis tube furnaces use silicon carbide (SiC), molybdenum disilicide (MoSi₂), or resistance wire as heating elements to ensure fast and uniform heating.
2. Tube Materials:
   The choice of tube depends on the temperature range and atmosphere. Quartz tubes are suitable for temperatures up to 1200°C, while alumina tubes can handle higher temperatures.
3. Temperature Control System:
   Equipped with PID digital controllers, these furnaces offer accurate temperature programming, multi-stage heating profiles, and precise control within ±1°C.
4. Gas Flow System:
   The inert gas inlet and outlet allow users to control the environment, ensuring oxygen-free pyrolysis and preventing unwanted oxidation.
5. Safety Features:
   Includes over-temperature protection, gas leakage detection, and automatic power-off functions for secure operation.

Applications of Pyrolysis Tube Furnace

1. Biochar and Carbon Material Production

A pyrolysis tube furnace is widely used to convert biomass into biochar under oxygen-free conditions. The resulting carbon-rich material is used for soil improvement, adsorption, and energy storage.

2. Catalyst Preparation

In chemical research, the furnace is employed to calcine and activate catalysts. The controlled heating environment ensures consistent composition and high surface area.

3. Polymer and Plastic Pyrolysis

Researchers use tube furnaces to investigate plastic recycling and polymer degradation, analyzing gas and oil yields under different temperatures.

4. Nanomaterial Synthesis

The device is essential for CVD (Chemical Vapor Deposition) or graphene growth, where precise temperature and gas control are critical for forming high-quality nanostructures.

5. Research and Quality Testing

In universities and industrial laboratories, the pyrolysis tube furnace serves for thermal stability testing, ash content analysis, and chemical reaction studies.

Advantages of Pyrolysis Tube Furnace

• Precise Temperature Control: Ensures reproducibility of experimental results.
• Uniform Heating Zone: Provides consistent thermal distribution for material uniformity.
• Flexible Design: Available in horizontal, vertical, and split configurations.
• Customizable Atmosphere: Supports vacuum, inert gas, or reactive gas environments.
• Energy Efficiency: Advanced insulation materials reduce heat loss and power consumption.

Types of Pyrolysis Tube Furnaces

1. Horizontal Pyrolysis Tube Furnace:
   Ideal for continuous feeding and gas flow control. Commonly used in biomass pyrolysis.
2. Vertical Pyrolysis Tube Furnace:
   Suitable for small samples and batch testing; offers easy temperature gradient control.
3. Split Tube Furnace:
   Designed for easy tube replacement and sample loading, particularly convenient for rapid experiments.
4. Rotary Pyrolysis Tube Furnace:
   Ensures better mixing and uniform heating, suitable for powder and granular materials.

Maintenance and Operation Tips

1. Always purge the tube with inert gas before heating to remove air.
2. Avoid thermal shock by allowing gradual heating and cooling.
3. Regularly check gas connections and seals for leaks.
4. Clean residues and replace tubes periodically to maintain performance.
5. Use proper insulation gloves and safety equipment when handling hot components.

Choosing the Right Pyrolysis Tube Furnace

When selecting a pyrolysis tube furnace, consider:

• Maximum operating temperature
• Heating zone length
• Tube diameter and material compatibility
• Atmosphere requirements (inert, vacuum, or reactive gas)
• Sample size and type
• Automation and data recording functions