📋 Case Study

Recycled PET Flakes Purification for Food Contact — Indorama PET Recycling, Rotterdam

Residual acetaldehyde and organic contaminants exceeding EU migration limits; chlorine-based wash causing equipment corrosion and AOX discharge

🏗️ Project Overview

Validation of supercritical CO₂ cleaning for post-consumer PET flake decontamination

🎯 Challenge

Residual acetaldehyde and organic contaminants exceeding EU migration limits; chlorine-based wash causing equipment corrosion and AOX discharge

🔧 Design Approach

Replaced aqueous alkaline wash with scCO₂ extraction (15 MPa, 65°C); integrated inline FTIR for contaminant verification; added melt filtration with ceramic sintered media

📐 Design Diagram

AI-generated project design illustration

📐 Key Calculations

AOX Elimination Rate

(Influent AOX − Effluent AOX) / Influent AOX × 100

Result: 100%

Eliminates wastewater toxicity reporting

scCO₂ Energy Intensity

kWh/kg flake

Result: 0.42

Benchmark against conventional steam-stripping (1.8 kWh/kg)

📊 Results

Achieved EFSA food-contact compliance; zero AOX discharge; 22% lower OPEX vs legacy process

💡 Lessons Learned

• •scCO₂ parameters require precise tuning per polymer batch heterogeneity
• •Inline spectroscopy reduces QA cycle time from 48h to <15min

✅ Key Takeaways

• 1scCO₂ parameters require precise tuning per polymer batch heterogeneity
• 2Inline spectroscopy reduces QA cycle time from 48h to <15min