Simulation and Optimization of Defluorination and Desulfurization …
127
Results and Discussion
Distribution of Absorption Rate in Axial Position
The distribution laws of the absorption rate in the axial position of the filled tower
were studied when the gas flow rate and liquid flow rate were constant by using the
DN 16 mm Bauer ring. The volume mass transfer coefficient and CO 2 utilization
rate in the axial position were obtained by measuring the changes of solution pH
values at the quartering position of the filler section. It can be seen from Fig. 2 that
most of the CO 2 at position 1 is close to the top of the tower, and most of the CO 2
has been reacted at the bottom, so the solution at position 1 absorbs less CO 2 . The
volumetric mass transfer coefficient AK and CO 2 utilization ratio are relatively low,
and the mass transfer rate of CO 2 absorbed by NaOH is relatively slow. Position 2 and
position 3 belong to the middle part of the filler layer, and the volumetric mass transfer
coefficient and CO 2 utilization rate of the two places are similar, and the reaction
rate of the gas staying in the filler section is similar at these two places. Position 4
is close to the air inlet, where a large amount of CO 2 reacts with the solution, the
volumetric mass transfer coefficient and CO 2 utilization rate are relatively high, and
the mass transfer rate of CO 2 absorption by NaOH is relatively fast.
Fig. 2 Volumetric mass transfer coefficient AK and CO 2 utilization factor at axial positions. (Color
figure online)
127
Results and Discussion
Distribution of Absorption Rate in Axial Position
The distribution laws of the absorption rate in the axial position of the filled tower
were studied when the gas flow rate and liquid flow rate were constant by using the
DN 16 mm Bauer ring. The volume mass transfer coefficient and CO 2 utilization
rate in the axial position were obtained by measuring the changes of solution pH
values at the quartering position of the filler section. It can be seen from Fig. 2 that
most of the CO 2 at position 1 is close to the top of the tower, and most of the CO 2
has been reacted at the bottom, so the solution at position 1 absorbs less CO 2 . The
volumetric mass transfer coefficient AK and CO 2 utilization ratio are relatively low,
and the mass transfer rate of CO 2 absorbed by NaOH is relatively slow. Position 2 and
position 3 belong to the middle part of the filler layer, and the volumetric mass transfer
coefficient and CO 2 utilization rate of the two places are similar, and the reaction
rate of the gas staying in the filler section is similar at these two places. Position 4
is close to the air inlet, where a large amount of CO 2 reacts with the solution, the
volumetric mass transfer coefficient and CO 2 utilization rate are relatively high, and
the mass transfer rate of CO 2 absorption by NaOH is relatively fast.
Fig. 2 Volumetric mass transfer coefficient AK and CO 2 utilization factor at axial positions. (Color
figure online)