Removal of Carbon Dioxide by Absorption in a Cross-flow Rotating Packed Bed
Special Symposium - Environmental Protection & Sustainability
Environmental Protection & Sustainability (EPS - Poster)
Keywords: Rotating Packed Bed, High Gravity, Carbon Dioxide, Cross-flow, Absorption
A rotating packed bed (RPB) for enhancing gas-liquid mass transfer is to contact liquid and gas in a centrifugal field by rotating a doughnut-shaped packing element. It can provide a thinner liquid film and small droplet to increase gas-liquid contact area owing to high centrifugal acceleration. It has a low tendency of flooding, high process capacity, small spatial requirement, high efficiency, low energy consumption, and low operating and capital costs. A countercurrent-flow RPB has been demonstrated to be a high-efficiency gas-liquid contactor in distillation, absorption, stripping, deaeration and reactive precipitation.
A cross-flow RPB was investigated for its applicability in carbon dioxide absorption. The test systems involved the absorption of carbon dioxide by sodium hydroxide, MEA and AMP solution. The cross-flow RPB has an inner radius of 2.4 cm, an outer radius of 4.4 cm and an axial height of 12.0 cm. Wire mesh was used as packings. Rotor speeds ranged from 400 to 1800 rpm. The overall volumetric gas-side mass transfer coefficient increased with rotor speed, gas flow rate, liquid flow rate and NaOH concentration, however, decreased with carbon dioxide concentration. MEA aqueous solution was superior to NaOH aand AMP aqueous solutions at the same absorbent concentration for carbon dioxide absorption.
The obtained results demonstrated that a cross-flow RPB could achieve mass transfer efficiencies equivalent to countercurrent-flow RPB. Consequently, a cross-flow RPB without flooding point would be applicable in the removal of carbon dioxide from the gas stream with higher flow rate by absorption with great potential.
Presented Monday 17, 13:30 to 15:00, in session Environmental Protection & Sustainability (EPS - Poster) S-7P.
