超重力系統中以高濃度混合醇胺吸收二氧化碳

CO2 Capture by High Concentration of Blended Alkanolamine Solution in a Rotating Packed Bed

馬杏如(Hsing-Ju Ma)

指導教授 ： 陳昱劭

中原大學/工學院/化學工程研究所/碩士(2015年)

https://doi.org/10.6840/cycu201500561

摘要

本研究於旋轉填充床反應器，利用化學吸收法移除氣相的二氧化碳，吸收劑為醇胺溶液，包含MEA/PZ、MMEA/PZ、MMEA、MEA、MEA/AMP及AMP，藉實驗測量系統中氣體出口二氧化碳濃度，改變轉速、氣體流率、液體流率、吸收劑溫度、濃度及種類組合，討論與移除率、總括體積氣膜質傳係數及氣液相的二氧化碳吸收含量之影響與其原因。
實驗結果顯示移除率會隨液體流率及醇胺濃度提高而上升，隨氣體流率提高而下降，在600 ~ 1800 rpm移除效果隨著轉速增加而變好。在吸收劑方面，MEA與MMEA的吸收效果優於AMP，而在MEA和MMEA中加入PZ有助移除率的提升，因為與二氧化碳反應之速率PZ > MMEA > MEA > AMP。在溫度方面，MEA與MEA/PZ最好移除效果在323 K，MMEA與MMEA/PZ在333 K，而MEA/AMP在313 K。總括體積氣膜質傳係數則隨醇胺濃度增加與液體流量而提高。隨著轉速及氣體流率的變化則較為複雜，因為高轉速、高氣液體流率皆會使質傳阻力下降，但也同時降低了氣液間的接觸時間。二氧化碳吸收含量隨著液體流量與醇胺濃度增加而降低。
本研究在吸收劑組成為90 wt% MMEA+10 wt%PZ，於2400 rpm時，有最佳之二氧化碳移除率。另外，所得到質傳單元高度(HTU)值約為0.6 ~ 9.7 cm，遠比傳統填充床之值小，顯示旋轉填充床在高達100 wt%之醇胺濃度下，具有優異的處理效能。

關鍵字

捕捉二氧化碳 ； 醇胺類 ； 超重力

並列摘要

In this study, alkanolamines including monoethanolamine (MEA), piperazine (PZ), 2-amino-2-methyl-1-propanol (AMP) and 2-methyl-amino- ethanol (MMEA) with a concentration ranging from 30-100 wt% were used to capture CO2 from gas stream in a rotating packed bed. The effects of rotor speed, gas and liquid flow rates, temperature and the concentration and composition alkanolamines on CO2 removal efficiency (E) , mass transfer coefficient (KGa) and CO2 loading were investigated.
Experimental results showed that CO2 removal efficiency increased with increasing liquid flow rate, concentration of alkanolamines and rotor speed ranging between 600 and 1800rpm, but decreased with increasing gas flow rate. Compared with MEA and AMP, MMEA showed the highest removal efficiency. Additionally, adding PZ could effectively enhance the E value. However, the optimal temperature of the mixture of MEA and MMEA/PZ, MMEA and MMEZ/PZ, and MEA/AMP is 323, 333, and 313K, respectively. The mass transfer coefficient values increased with increasing liquid flow rate and concentration of alkanolamines. The effects of rotor speed and gas rate were complex because higher rotor speed and gas flow rate both reduced not only mass transfer resistance but also the contact time of gas and liquid in RPB. The CO2 loading decreased with liquid flow rate and concentration of alkanolamines.
Among the alkanolamines tested in this study, the highest CO2 removal efficiency was obtained using 90 wt% MMEA/10 wt% PZ. The HTU of RPB was 0.6~9.7 cm, which was smaller than that of a conventional packed column. This indicates that Rotating Packed Bed demonstrates the capability for CO2 capture using high-concentration alkanolamines.

並列關鍵字

CO2 Capture ； Alkanolamine ； Rotating Packed Bed

參考文獻

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