Adsorption Thermodynamics for Process Simulation.

Area of Science:

• Thermodynamics
• Chemical Engineering
• Materials Science

Background:

• Adsorption is a vital separation technology in industry, yet rigorous thermodynamic modeling of multicomponent systems remains a challenge.
• Current models like extended Langmuir and adsorbed solution theory have limitations, forcing reliance on expensive pilot studies for process development.

Purpose of the Study:

• To highlight the need for advanced adsorption thermodynamic models and critique existing ones.
• To present generalized Langmuir and Brunauer-Emmett-Teller isotherms for accurate multicomponent adsorption equilibrium prediction.

Main Methods:

• Derived an activity coefficient model to account for adsorbate-adsorbent interactions.
• Generalized classical isotherms by replacing concentrations with activities for multicomponent systems.
• Extended models to both monolayer and multilayer adsorption scenarios.

Main Results:

• Developed generalized Langmuir and Brunauer-Emmett-Teller isotherms requiring minimal, physically meaningful parameters.
• These models effectively address adsorbent surface heterogeneity, enthalpy, nonideality, and multilayer adsorption.
• Demonstrated capability to predict adsorption azeotrope formation.

Conclusions:

• The generalized models offer a more rigorous and accurate approach to thermodynamic modeling of adsorption equilibrium.
• High-quality, comprehensive adsorption data are crucial for reliable model parameter determination and process optimization.
• These advances can significantly reduce the need for extensive pilot studies in developing adsorption units.