Thermal treatment of petroleum contaminated soils by a fluidized bed desorber

Abstract

A novel type of fluidized bed desorber was developed for the remediation of petroleum-contaminated soils at low temperature with high efficiency. The performance of the fluidized bed desorber was experimentally investigated in two different operation modes. Results of continuous operation of fluidized bed indicated that the effect of the mass ratio of the fluidizing gas flow rate to the feed rate of contaminated soil was not significant at temperatures above 300 degrees C as long as proper fluidization was ensured. Periodic fluidization mode was tested aiming at reduction of off-gas volume. Effects of cycle time and split fraction on desorption efficiency were investigated. Within the range of experimental conditions, desorption efficiency decreased with increase of cycle time and split due to defluidization in the bed. With suitable choice of cycle time and split, periodic fluidization of the desorber enabled considerable reduction of off-gas volume without compromising desorption efficiency.