Study On Flow Characteristics And Desulfurization Performance In A Rotating Packed Bed With Polyethylene Packing

Rotating packed bed (RPB) is typical chemicak process intensification equipment. The liquid will be rened into fluid element (such as membrane, silk, drops and pieces) by the large shear force generated RPB, which will greatly increase the phase contact area, and finally enhance the separation and reaction process.The RPB packing should have the characteristics of corrosion resistance and low pressure drop. So, the RPB can meet the requirement of long term operation in industry. In this paper, the polyethylene packing was used as current RPB packing and this study focused on pressure drop, liquid folw characteristic and desulfurization effect by ammonia-based solution. The detail research and results are as follows:1. Flow characteristics study of RPB with Polyethylene PackingThe effect of liquid flow rate, gas flow rate and rotational speed on the pressure drop was investigated in a counter current rotating packed bed by air-water system. The gas pressure drop increased with the rotational speedreducing or air flow rate increasing in dry and wet RPB, and the liquid flow rate had almost no effect on pressure drop in the wet counter current RPB. For the same situation, the pressure drop in the wet RPB was lower than the the pressure drop in the dry RPB. The pressure drop for structured packing was lower, when compared with the pressure drop with polyethylene packing under the same operating conditions.Compared with experimental data of polyethylene packing, the predicted data obtained from above correlation was in small deviation of ±10%, respectively.Through high speed photography technology, the mean droplet diameter was decreased with the increasing of bed size and rotational speed of RPB, which was 0.25-1.10 mm2. Study on desulfurization performance by ammonia-based wet methodEffects of operating parameters, such as the rotational speed, liquid flow rate, gas flow rate, liquid-gas ratio, inlet concentration of SO2, the alkalinity of absorbent and gas-liquid content model on the removal efficiency of SO2 were examinedin counter current RPB with structured packing and polyethylene packing by using (NH4)2SO3-NH4HSO3 mixture solution as the absorbent. With the increasing of rotational speed, liquid flow rate or alkalinity, the SO2 removal efficiency increased. With the reducing of gas flow rate, SO2 inlet concentration, liquid-gas rate, the SO2 removal efficiency was also increased. The SO2 removal efficiency of structured packing and polyethylene packing was above 95% and 97%, respectively. Based upon mass balance, the gas-side overall mass transfer coefficient (Kya) was available and obtained. Compared with experimental data of polyethylene packing, the predicted Kya obtained from above correlation was in small deviation of ±5%.