Toluene mass transfer characterization in a biotrickling filter

作者：Lebrero Raquel; Estrada Jose M; Munoz Raul; Quijano Guillermo^*

来源：Biochemical Engineering Journal, 2012, 60: 44-49.

DOI：10.1016/j.bej.2011.09.017

• Biological off-gas treatment
• Biotrickling filter
• Mass transfer modeling
• Toluene
• Volatile organic compounds

Biotrickling filters (BTFs) devoted to air pollution control often present mass transfer limitations for hydrophobic volatile organic compounds (VOCs). Under such limiting conditions, BTF design and scale-up should be based on mass transfer data. A general and simple model was developed to characterize the VOC transfer by means of the overall mass transfer coefficient (K(L)a). The K(L)a values were obtained by fitting the model to experimental data of toluene absorption obtained at empty bed residence times (EBRT) from 7 to 50 s. The model fitted well the experimental data (r(2) = 0.97) and the resulting K(L)a values ranged from 35 to 113 h(-1). These values are similar to those reported in the literature for BTF despite the lower liquid recycling velocity here used (0.6 m h(-1)). A critical gas-to-liquid flow rate ratio (Q(G)/Q(L)) of 200, above which K(L)a was poorly increased, was observed. In addition, the individual film coefficients were estimated from the Van Krevelen and Hoftijzer correlations, which revealed that the main resistance for toluene mass transfer was in the liquid film regardless of the EBRT used. Finally, the high mass transfer potential of BTFs was confirmed by estimating the mass transfer capacity under varied operating conditions.

• 出版日期2012-1-15