Heating activated carbon by electromagnetic induction Original Research Article

The purpose of this study is the use of electromagnetic induction to heat activated carbon. The ultimate goal is to get an original process to regenerate adsorbants loaded with the volatile organic compounds present in air or water. The first step was to explore the possibilities of heating granular activated carbon with this technology. In order to get the best operating parameters, the methodology of experimental research was applied. The carbon had to be selected according to its origin (coconut) and its granulometry (average diameter 3.8 mm). In addition, the importance of electric power and frequency was demonstrated. The incorporation of susceptors into the carbon really improves the energy yield. Efficiency mainly depends on the granulometry of the activated carbon and the susceptors, for a given current at a frequency of 263 kHz. In the second step, the heating mechanisms, performed on a large pilot unit, followed mainly a surfacic mode (circular motion) and a volumic mode (intra-particle). A large size reactor has a positive effect on the energy yield. The suceptor is used only to obtain a volumic mode of GAC filter heating and not to improve the heating efficiency. Equations enabled us to model the electric power absorbed by the granular medium. Experimental and calculated data correlated well. In industrial applications of the induction heating, a lower frequency (from 20 to 263 kHz) can be applied. The energy efficiency is found to be in the range of 40 to 80%.