Benzene adsorption and hot purge regeneration in activated carbon beds

Experimental and theoretical studies were performed on adsorption of benzen e from nitrogen gas stream and thermal regeneration by hot nitrogen purge, in fixed beds charged with activated carbon. System temperature and effluen t concentration data were collected during adsorption-regeneration runs. A mathematical model was developed to simulate temperature and concentration data of adsorption and regeneration. The model developed was based on non-e quilibrium, non-isothermal and non-adiabatic conditions. Three heat transfe r resistances were considered in interfaces of gas-solid, gas-wall, and wal l-atmosphere. A linear driving force mass transfer model with a variable lu mped-resistances coefficient was found to provide an acceptable fit to the experimental data. Experimental and modelling results were used to study th e effects of adiabatic and non-adiabatic operations, contact time, gas velo city, regeneration temperature and initial bed loading on the regeneration efficiency. Besides, the specific energy requirement and purge gas consumpt ion were evaluated to discuss the process efficiency. (C) 2000 Elsevier Sci ence Ltd. All rights reserved.