When working with Plasticizer DOP (Dioctyl Phthalate), proper cleaning of the IBC containers after unloading is essential. DOP is a viscous and oily plasticizer with low volatility and high adhesion, which makes it difficult to remove using water alone.
If the container is not cleaned thoroughly, residual DOP can contaminate future batches or reduce product purity. Below is a proven industrial cleaning procedure for DOP IBC tanks.
1. Step One: Drain and Pre-Treatment
After unloading Plasticizer DOP, drain all remaining liquid completely. Use an absorbent cloth or scraper to remove visible residues from the bottom and inner walls of the IBC.
If a large amount of residue remains, add a small amount of solvent oil and gently heat the container to 50–60 °C, allowing the DOP to dissolve before draining.
2. Step Two: Solvent Cleaning
Use a strong organic solvent to dissolve and wash away the oily film of DOP.
Recommended solvents:
- No. 2 Solvent Oil (Naphtha)
- Xylene / Toluene
Procedure:
- Add approximately 5-10% of the IBC volume of solvent.
- Seal the lid and shake the container for 5–10 minutes.
- Drain the solvent completely.
- Repeat the process if oil traces remain.
These solvents have excellent dissolving power and are widely used in the plasticizer industry to remove DOP residues effectively.
3. Step Three: Alkali Washing (Oil Film Removal)
To remove any remaining DOP film, prepare an alkaline cleaning solution:
- 5–10 % Sodium Hydroxide (NaOH) in water
- Add a small amount of surfactant or industrial detergent for better results
Instructions:
- Heat the solution to about 50 °C (122 °F).
- Pour into the IBC container and soak or agitate for 15–30 minutes.
- Drain the alkali solution and rinse 3–5 times with clean water until the rinse water reaches neutral pH (~7).
4. Step Four: Drying
After washing, completely dry the container:
- Leave the IBC open in a well-ventilated area, or
- Use warm air (50–60 °C) for faster drying.
Ensure no odor or oily residue remains before refilling the IBC.
5. Safety and Environmental Precautions
- Perform all cleaning steps in a well-ventilated area away from flames.
- Wear chemical-resistant gloves, goggles, and a mask when handling solvents or alkali.
- Collect and dispose of waste solvent and alkali water according to environmental regulations.
Conclusion
Cleaning IBC containers after unloading Plasticizer DOP requires both solvent and alkali washing to achieve complete residue removal.
Using No. 2 Solvent Oil (Naphtha) or Xylene / Toluene followed by 5–10 % NaOH washing at 50 °C ensures that the container is free from DOP residues, maintaining product quality and safety.
Properly cleaned IBCs contribute to efficient, sustainable, and contamination-free DOP plasticizer operations.