Volatile organic compound adsorption in a gas-solid fluidized bed

Area of Science:

• Chemical Engineering
• Adsorption Science
• Fluidization Technology

Background:

• Fluidization is crucial for processes like catalysis, drying, and combustion.
• Understanding adsorption dynamics in different reactor types is key for process optimization.
• Zeolite ZSM-5 and activated carbon are common adsorbents with distinct properties.

Purpose of the Study:

• To compare dynamic adsorption characteristics and rates in bubbling fluidized beds and fixed beds.
• To investigate the influence of bed type, particle size, and intraparticle mass transfer on adsorption.
• To compare the adsorption performance of ZSM-5 zeolite and activated carbon for methanol and isobutane.

Main Methods:

• Experimental comparison of adsorption in bubbling fluidized beds and fixed beds at identical gas flow rates, residence times, and bed heights.
• Adsorption experiments using ZSM-5 zeolite and activated carbon with methanol and isobutane.
• Fourier Transform Infrared (FTIR) spectroscopy for gas concentration quantification.

Main Results:

• Bubbling fluidized beds exhibited higher adsorption rates than fixed beds under identical conditions.
• Intraparticle mass transfer was the dominant factor influencing adsorption rates.
• Adsorption capacity of ZSM-5 zeolite was similar in both bed types; activated carbon showed higher capacity for isobutane than zeolite but at a lower rate.

Conclusions:

• Fluidization enhances adsorption rates, primarily due to improved intraparticle mass transfer.
• Bed type significantly impacts adsorption rate, but not necessarily adsorption capacity for zeolites.
• Activated carbon demonstrates superior adsorption capacity for isobutane compared to ZSM-5 zeolite.