Optimization of a 100% Product Utilization Process for LPG Separation Based on Distillation-Membrane Technology.

Area of Science:

• Chemical Engineering
• Separation Processes
• Process Optimization

Background:

• Liquefied petroleum gas (LPG) requires efficient fractionation for component recovery.
• Existing methods may not fully optimize the separation of propane, n-butane, and isobutane.
• Hybrid processes offer potential for enhanced separation efficiency.

Purpose of the Study:

• To techno-economically optimize a hybrid distillation-membrane process for complete LPG fractionation.
• To achieve high-purity recovery of propane, n-butane, and isobutane.
• To identify optimal membrane configurations and parameters for economic viability.

Main Methods:

• Process simulation and sensitivity analysis were employed.
• A two-stage membrane system with MFI zeolite hollow-fiber membranes was designed.
• Key membrane parameters (area, permeance, separation factor) were systematically optimized.

Main Results:

• A two-stage membrane process with partial residue-side reflux showed superior economic performance (31.58 USD/h operating cost).
• Optimal parameters included a membrane area of 800 m², n-butane permeance of 0.9 kg·m⁻²·h⁻¹, and a separation factor of 40.
• The optimized process achieved high n-alkane recovery while minimizing energy and capital costs.

Conclusions:

• The optimized hybrid distillation-membrane process is highly efficient for LPG fractionation.
• This approach offers an economically viable strategy for the complete utilization of LPG components.
• The study demonstrates the effectiveness of integrating distillation and membrane separation for complex hydrocarbon mixtures.