453270 Advances in the Use of a Bio-Physicochemical Model to Characterize, Optimize the Chemical Absorption-Biological Reduction Integrated System for NO Removal

Monday, November 14, 2016: 10:05 AM
Union Square 14 (Hilton San Francisco Union Square)
Jingkai Zhao, Meifang Li and Wei Li, Institute of Industrial Ecology and Environment, College of Chemical and Biological Engineering, Zhejiang University, Hangzhou, China

One promising technology for NOx removal from flue gas is the chemical absorption-biological reduction (CABR) integrated process, in which NO is absorbed by aqueous solution of Fe(II)EDTA and the absorption product, Fe(II)EDTA-NO, is reduced biologically. At the same time, Fe(II)EDTA, oxidized by O2 in flue gas, could be regenerated in a function of iron-reducing bacteria.

A kinetic model based on mass transfer coupled with chemical reaction and bioreduction was developed to simulate and predict the NOx removal by the CABR system in a bio-trickling filter. The developed model was validated by the experimental results (the average relative deviation kept within 5.72%) under different operating conditions, e.g. NO/O2 concentration, gas/liquid flow rate, and subsequently was used to predict the system performance. NO distribution at different inlet concentrations in the gas phase along the bio-trickling filter was also modeled and predicted.

Furthermore, the liquid flow rate and total iron concentration were optimized for >90% NO removal efficiency, which were 38.8 L h-1 and 10 mM under the typical operating condition (2 L min-1 gas stream containing 3% (v/v) oxygen and 500 ppm NO) respectively. Sensitivity analysis found that the performance of the CABR process was controlled by the bioreduction activity of Fe(III)EDTA, and the least activity has been achieved. This work could help us with the scale-up design and operation of the CABR process in the industrial application.

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See more of this Session: Fundamentals of Environmental Kinetics and Reaction Engineering
See more of this Group/Topical: Environmental Division