A distillation column is a core mass-transfer device used in chemical separation. It leverages differences in the volatility (boiling points) of components within a mixture, employing repeated partial vaporization and partial condensation—occurring throughout the column—to achieve the high-purity separation of liquid mixtures. Distillation columns are widely utilized across sectors such as petrochemicals, fine chemicals, pharmaceuticals, food processing, and environmental solvent recovery. They enable continuous, large-scale, high-purity separation processes, with separation efficiencies reaching over 99%.

The liquid mixture to be separated is preheated and fed into the distillation column through an inlet located in the middle section. A reboiler at the bottom of the column heats the liquid, causing partial vaporization, and the resulting vapor rises through the column. At the top, a condenser converts the rising vapor back into a liquid; a portion of this condensate is returned to the top of the column as reflux, flowing downward. As the rising vapor and the descending reflux come into countercurrent contact—either on trays or across the surface of packing material—repeated heat and mass transfer occur: the more volatile components (light components) preferentially transfer into the vapor phase, while the less volatile components (heavy components) preferentially transfer into the liquid phase. With a sufficient number of theoretical stages, a high-purity light-component product is obtained at the top of the column, and a high-purity heavy-component product is recovered from the bottom, thereby achieving the continuous distillation separation of the mixture.

Separation of liquid mixtures: Separation of binary or multi-component systems with a boiling point difference of ≥5°C
Solvent recovery: Recovery and purification of organic solvents such as methanol, ethanol, acetone, toluene, and ethyl acetate
Fine chemicals: Fractional distillation and purification of intermediates, monomers, fragrances, and pharmaceutical raw materials
Petrochemicals: Crude oil fractionation, light hydrocarbon separation, and aromatics separation
Food and pharmaceuticals: Alcohol distillation, purification of natural extracts, and recovery of pharmaceutical-grade solvents
Operating pressure: Atmospheric, reduced (vacuum), or elevated pressure
Operating temperature: Determined by the specific material system; typically ≤300°C

1. Common Materials
1) Carbon Steel
Advantages: Low cost; suitable for handling non-corrosive materials and media with mild corrosivity.
Disadvantages: Not suitable for handling strong acids, strong bases, or highly corrosive substances.
2) Stainless Steel (304, 316L)
Advantages: Good corrosion resistance; 316L, in particular, is suitable for more aggressive acidic or alkaline media.
Disadvantages: High material cost.
3) Plastic-Lined (e.g., PTFE-lined)
Advantages: Excellent corrosion resistance; suitable for environments involving strong acids and bases.
Disadvantages: Limited mechanical strength.

2. Suitability of Materials for Different Operating Conditions
For ambient-temperature, non-corrosive materials (e.g., ethanol distillation): Carbon steel is an economical and practical choice.
For environments involving weak acids, weak bases, or moisture (e.g., distillation of acidic substances): 304 stainless steel.
For high-temperature and highly corrosive environments (e.g., media containing strong acids or chlorides): 316L stainless steel.

Continuous distillation/separation and solvent recovery systems for industries such as petrochemical plants, fine chemical plants, pharmaceutical plants, pesticide plants, fragrance/flavor manufacturing plants, food processing plants, new energy material plants, electronic chemical plants, and waste solvent recovery centers.

High Separation Efficiency: Features high-performance packing or tray designs with an ample number of theoretical stages, enabling product purity of over 99.5%.
Continuous Operation: Supports 24-hour continuous feeding and discharge, ensuring high production efficiency.
Controllable Energy Consumption: Optimized reflux ratio design, combined with heat recovery in reboilers and condensers, reduces operational energy consumption.
Wide Range of Materials: Available in various materials—such as Q235 carbon steel, SS304, SS316L, titanium, and PTFE-lined steel—to accommodate corrosive substances.
Comprehensive Structural Options: Offers both tray columns (sieve, valve, or bubble-cap trays) and packed columns (structured or random packing), selected based on the specific process system.
Stable Operation: Equipped with automated controls for liquid level, temperature, pressure, and reflux ratio, offering high operational flexibility and consistent performance.
Compliance and Safety: Designed and manufactured in accordance with pressure vessel standards; includes essential safety accessories such as safety valves and rupture discs.