| Summary: | 碩士 === 中原大學 === 化學工程研究所 === 104 === In this study, a mixture of alkanolamine, such as MEA and MMEA, with a deep eutectic solvent (DES) of choline chloride (ChCl)/ethylene glycol (EG) used as an absorbent to capture CO2 from gas stream in a rotating packed bed. The effects of rotating speed, gas flow rate, temperature, concentration of alkanolamine and ratio of water and DES in the absorbent on CO2 removal efficiency (E), mass transfer coefficient (KGa) and CO2 loading were investigated.
Experimental results showed that CO2 removal efficiency increased with increasing temperature, concentration of alkanolamine, ratio of water in the absorbent and rotating speed ranging between 600 and 1800 rpm, but decreased with increasing gas flow rate. A decreased of ratio of water in the absorbent reduced the removal efficiency because of the increasing viscosity. The removal efficiency of MMEA is higher than that of MEA, because of the reaction rate of MMEA is higher. The mass transfer coefficient values increased with increasing rotating speed, temperature, concentration of alkanolamine and ratio of water in the absorbent. Increasing gas flow rate reduced the contact time of gas and liquid in the rotating packed bed, and thus, the mass transfer coefficient decreased with the gas flow rate. The regeneration energy of each absorbent was calculated in this study. Results showed that the regeneration energy decreased with increasing the ratio of water in the absorbent. Besides, the regeneration energy of MMEA is lower than that of MEA.
In this study, an optimum composition of absorbent of MMEA/DES/H2O (30:40:30) was obtained. Compared with 30 wt% MEA solution, the removal efficiency of the proposed absorbent was increased from 69% to 86.8% at gas flow rate of 50 L/min, liquid flow rate of 0.1 L/min, while the regeneration energy can be reduced from 3.61 GJ/ton CO2 to 2.88 GJ/ton CO2. This shows that the use of DES mixed with alkanolamine has a great potential for CO2 capture in a higee system.
|
|---|
