📋 Case Study
Supercritical Fluid Extraction (SFE) Process Design for Caffeine Recovery
Low selectivity and high CO₂ consumption due to poor phase behavior prediction
🏗️ Project Overview
Pharmaceutical-grade caffeine extraction from spent coffee grounds in Colombia
🎯 Challenge
Low selectivity and high CO₂ consumption due to poor phase behavior prediction
🔧 Design Approach
Peng-Robinson + van der Waals mixing rules calibrated to experimental solubility data
📐 Design Diagram
AI-generated project design illustration
📐 Key Calculations
Solubility Enhancement Factor
y_CO₂·P / P_sat
Result: 127×
Quantifies supercritical advantage over liquid solvent
Critical Mixture Pressure
P_c_mix = Σx_i·P_c_i + k_ij·x_i·x_j
Result: 8.9 MPa
Defines minimum operating pressure
📊 Results
Selectivity increased from 4.2× to 19.7×, CO₂ usage reduced by 63%, purity >99.95 wt% achieved💡 Lessons Learned
- •Binary interaction parameters (k_ij) must be regressed from ternary (CO₂–caffeine–water) data
- •Joule–Thomson cooling effects required explicit enthalpy path modeling
✅ Key Takeaways
- 1Binary interaction parameters (k_ij) must be regressed from ternary (CO₂–caffeine–water) data
- 2Joule–Thomson cooling effects required explicit enthalpy path modeling