| Summary: | 碩士 === 中原大學 === 化學工程研究所 === 104 === In this study, using chemical absorption of CO2 was carried out in rotating packed bed using ethanolamine (MEA) and 2-methylethanolamine (MMEA) solution. Effect of rotor speed, gas flow rate, CO2 loading and alkanolamine concentration on CO2 removal efficiency (E) and mass transfer coefficient (KGa) was investigated and the regeneration energy was calculated.
Experimental result showed that, when lean loading was 0 mol/mol, CO2 removal efficiency increased with rotor speed and alkanolamine concentration, but decreased with gas flow rate. When lean loading was higher than 0.15 mol/mol, a reduction of the removal efficiency of the absorbent with an alkanolamine concentration of 80 and 100 wt% was observed because the viscosity was significantly increased. The removal efficiency of MEA and MMEA was similar when lean loading was 0 mol/mol, and the removal efficiency of MMEA became higher for the lean loading higher than 0.15 mol/mol.
The regeneration energy decreased with increased alkanolamine concentration. Besides, the regeneration energy of MMEA was lower than those of MEA. Compared with a conventional packed bed, the KGa was 15 times higher in an RPB because of the higher gas-liquid interfacial area.
Based on the absorption efficiency and regeneration energy required, an optimum absorbent of 60 wt% MMEA was proposed as lean loading was higher than 0.15 mol/mol. Compared with 40 wt% MEA solution, a 7.3% enhancement of removal efficiency and a 17.8% reduction of regeneration energy were achieved by using 60 wt% MMEA solution at a gas rate of 10 L/min, rotor speed of 2400 rpm and lean loading of 0.15 mol/mol. The enhancement of removal efficiency can be further increased to 50% at a lean loading of 0.25 mol/mol. This indicates that using high concentration of MMEA solution has great potential for CO2 capture in an RPB.
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