📋 Case Study

Heat Integration in Ethylene Oxide Absorption Column

Poor CO₂ co-absorption leading to catalyst deactivation and product loss

🏗️ Project Overview

Retrofit of EO recovery unit in Gulf Coast petrochemical plant

🎯 Challenge

Poor CO₂ co-absorption leading to catalyst deactivation and product loss

🔧 Design Approach

Added structured packing section with staged solvent cooling and inter-stage heat exchange

📐 Design Diagram

_og = 1.42 m Solvent (x_in) Gas (y_in) Gas (y_out) Solvent (x_out) Cooling Cooling CO₂ co-absorption → catalyst deactivation α = 12.8 (y_in − y_out)/(x_out − x_in) Heat Integration in EO Absorption Column

AI-generated project design illustration

📐 Key Calculations

Overall Mass Transfer Unit Height (HTUog)

H = G/(K_G·a·A)

Result: 1.42 m

Determines required packing height

Solvent Loading Ratio

α = (y_in − y_out)/(x_out − x_in)

Result: 12.8

Drives reboiler duty and regeneration energy

📊 Results

CO₂ impurity reduced from 120 ppm to <8 ppm; ethylene oxide yield increased by 3.2%

💡 Lessons Learned

• •Local HTU variation along column height invalidates single-value assumptions
• •Solvent temperature profile impacts both kinetics and equilibrium

✅ Key Takeaways

• 1Local HTU variation along column height invalidates single-value assumptions
• 2Solvent temperature profile impacts both kinetics and equilibrium