Article

Measurements and modeling of heat generation in a trickling biofilter for biodegradation of a low concentration volatile organic compound (VOC)

Institute of Engineering Thermophysics, Chongqing University, Chongqing 400044, PR China; Academy of Bioengineering, Chongqing University, Chongqing 400044, PR China
Chemical Engineering Journal DOI:10.1016/j.cej.2007.09.043

ABSTRACT The experimental and theoretical heat generation behavior of a trickling biofilter treating toluene is discussed. The experimental results show that the temperature of the packed bed has a significant effect on the purification performance of the trickling biofilter and that an optimal operation temperature exists between 30 and 40 °C. During the gas–liquid co-current flow, the temperature in the packed bed gradually rises along the direction of the gas and liquid flow due to the exothermic biodegradation of toluene. The temperature rise between the inlet and outlet of the trickling biofilter increases with an increase in the gas flow rate and inlet toluene concentration. In addition, a larger liquid flow rate leads to a smaller temperature rise. The heat generation process occurring in the trickling biofilter is modeled by representing the packed bed as an equivalent set of parallel capillary tubes covered by the biofilm. The temperature profile in the packed bed during the liquid–gas co-current flow is analyzed by simultaneously solving the problem of gas–liquid two-phase flow and heat and mass transfer through the liquid film and biofilm. It is shown that the model agrees well with the experimental data, predicting the variations of the temperature rise between the inlet and outlet of trickling biofilter with the increasing gas and liquid flow rates.

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Keywords

experimental data
 
gas flow rate
 
gas–liquid co-current flow
 
gas–liquid two-phase flow
 
increasing gas
 
inlet toluene concentration
 
larger liquid flow rate
 
liquid film
 
liquid flow
 
liquid flow rates
 
liquid–gas co-current flow
 
mass transfer
 
optimal operation temperature
 
parallel capillary tubes
 
purification performance
 
smaller temperature rise
 
temperature profile
 
theoretical heat generation behavior
 
trickling biofilter
 
trickling biofilter increases
 

Qiang Liao