Experimental study on the synergetic removal of fine particles by wet flue gas desulfurization tower with a flow pattern control device

Investigation into the Dissolution Kinetics of Different MgO Desulfurizers in Flue Gas Desulfurization

The paper introduced hydrophilic functional groups on the surface of the MgO desulfurizer to improve its dispersion and hydrophilicity on the basis of reducing the particle size of the MgO desulfurizer to the nanometer level. Mechanical grinding technology was used to improve the traditional two-step method to lay the foundation for its large-scale production. The stability test showed that the ζ potential of the 5 wt % modified MgO desulfurizer was greater than 50 mV with 30 days of storage, and the sedimentation rate was not more than 7%. The dissolution reactivity and kinetics experiments showed that the decrease of particle size and the increase of hydrophilicity and dispersion were conducive to accelerating the dissolution rate of the MgO desulfurizer and reducing the apparent activation energy. Meanwhile, the good dissolution rate of the modified MgO nanofluids prepared by the improved method could reduce the liquid film mass transfer resistance and prolonged the penetration time.

Study on the Flow Characteristics of Desulfurization Ash Fine Particles in a Circulating Fluidized Bed

In view of the current status of catalytic cracking flue gas treatment, it is necessary to study the flow environment of desulfurization ash particles, which are a type of Geldart C particle, in a circulating fluidized bed (CFB) for semi-dry flue gas desulphurization using CFB technology. This study investigated the flow characteristics of desulphurization ash particles in a riser with an inner diameter of 70 mm and a height of 12.6 m, at a gas velocity of 4–7 m/s and a solids circulation rate of 15–45 kg/m2·s. The solids holdup in the axial distribution is relatively high near the bottom of the riser, and gradually decreases as the riser height increases, with a stable value from the middle to the top of the riser. In the radial distribution, the solids holdup of desulfurization ash particles is low in the center and high in the wall region. Within the above operating conditions, the solids holdup ranges from 0.008 to 0.025. The particle-based Archimedes number has a linear relationship with the solids holdup at all operating conditions.

A novel pilot-scale installation integrated of improved sieve-tray tower and wet electrostatic precipitator for paint mist removal

In order to overcome the problem of decrease of the spraying exhausts purification efficiency caused by the paint mist, the installation combining of the improved sieve-tray tower and the wet electrostatic precipitator (WEP) was used for the treatment of the pilot-scale 1,000 m³ paint waste gas. The characteristics of paint mist were investigated, showing that the size distribution of oil-based paint mist located in the range of 5.4-43.4 μm with an approximate symmetrical distribution under the pressure of 0.4 MPa. The size of paint mist less than 10 μm accounted for ~50% in quantity. It was revealed that the integrated setup was able to remove the concentration of oil-based paint mist with ~98% removal efficiency, in which the improved sieve-tray tower contributed ~94% particles removal. The soluble volatile organic pollutants (VOCs) of spraying exhaust gas were also captured by sieve-tray tower, promoting VOCs removal. At last, the feasibility of integrated setup used in paint mist removal was analyzed, including the secondary pollutants treatment. The results exhibited the setup has the potential for industrial applications.Implications: Fabricating a pilot-scale installation integrated of the improved sieve-tray tower and wet electrostatic precipitator to remove spraying exhaust gas in the furniture factory efficiently. This tech meets China's VOC emission policy.