Two-Stage Chemical Absorption-Biological Reduction System for NO Removal: Model Development and Footprint Estimation

Abstract

The two-stage chemical absorption-biological reduction (CABR) system, comprised of an absorption column and a bioreactor, is regarded as a promising option for NO removal from the middle-and small-sized boilers. In this work, a steadystate rate-based model was developed for the two-stage CABR system. The developed model was validated by the data obtained from a laboratory two-stage CABR setup and then used for the estimation of the footprints for treating a 5 × 10 4 m 3 h −1 flue gas from a 14 MW coal-fired steam boiler. For a baseline case (L/G = 10 L m −3 , C in,NO = 350 ppm, C in,O 2 = 6% (v/v)), the designed absorption column size was 3.60 × 8.75 m (d × h), while the bioreduction column was set at 3.60 × 8.50 m (d × h). Furthermore, sensitive analysis including the influence of gas concentrations, packing properties, and microorganism activities was investigated to optimize the design and operation of two-stage CABR process. Under optimized conditions, the footprint of the bioreactor can be downsized by 22.74%. It is believed that this work can provide fundamental data for the industrial application of the two-stage CABR system in the middle-and small-sized boilers.

Two-Stage Chemical Absorption–Biological Reduction System for NO Removal: System Start-up and Optimal Operation Mode

“…Given its features of having a low operation temperature and low carbon emission, CABR has been deeply studied in recent years, including microorganism strain breeding, − reactor design, − bioreduction mechanism, and limiting factors analyses. , Furthermore, modeling studies on the mass transfer and reaction kinetics have been explained, − which provided advantages and information for building an efficient lab-scale denitrification system.…”

Molecular oxygen activation enhancement by BiOBr0.5I0.5/BiOI utilizing the synergistic effect of solid solution and heterojunctions for photocatalytic NO removal

“…Moreover, long-term inhalation of NO can damage the respiratory tract of humans and cause serious diseases. In recent decades, the concentration of NO in the atmosphere increased considerably because of the rapid development of the modern industrial civilization.The situation is of concern and requires effective methods to remove NO or oxidize it to final harmless or non-hazardous products [3][4][5]. The products of NO oxidation are NO3or NO2, which are commonly converted into useful industrial materials.…”