In order to demonstrate this technology and develop engineering data for the design of a full-scale system, the Process Energetics Program has constructed a microwave regeneration pilot plant. This pilot plant features a moving bed desorber to regenerate polymeric adsorbents and recover the desorbed solvent (ketones). The microwave applicator for the desorber module consists of a 6" glass pipe inside of a multimode microwave cavity operating at 2450 MHz. As the adsorbent moves through the oven a counter-current nitrogen stream strips the VOCs from the hot adsorbent and transports the vapor to the solvent recovery module.
This continuous system is designed to mate with a fluidized-bed adsorber module and will process approximately 100 lbm/h of saturated adsorbent. The results at this frequency would scale directly to a 1.5' diameter column at industrial microwave frequencies (915 MHz). Initial test results suggest that the bed is regenerated uniformly and completely and with a minimum amount of stripping gas so that the solvent can be recovered by condensation at near-ambient temperatures.
Pilot Column Specifications:
Adsorption System
Laboratory Microwave Regeneration Pilot Plant
(Solvent Recovery System and Moving Bed Desorber)
Laboratory Adsorption System
(Fixed Bed Adsorber and Vapor Production System)
Microwave Regeneration Desorber Column Inlet
Microwave Heating Zone w/ Dowex Optipore Adsorbent
Microwave Regeneration Desorber Column Outlet
Adsorbent Sampling Port