碳酸鈉和碳酸鉀負載於活性碳吸收煙道氣中二氧化碳之研究

Absorption of CO2 from Flue Gas by Na2CO3 and K2CO3 Supported on Activated Carbon

蔡志凡(Chi-Fan, Tsai)

指導教授 ： 施信民

國立臺灣大學/工學院/化學工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.00552

摘要

本研究使用微分床反應器探討碳酸鉀和碳酸鈉負載於活性碳上吸收煙道氣中二氧化碳之能力，操作條件為溫度60℃、相對濕度50~90%RH、二氧化碳濃度0~50%以及二氧化硫濃度0~ 1000ppm。
在二氧化碳與二氧化硫同時存在下，碳酸鉀反應生成碳酸氫鉀以及亞硫酸氫鉀，碳酸鈉則生成碳酸氫鈉以及亞硫酸鈉。只與二氧化碳反應時，增加二氧化碳濃度對碳酸鉀/活性碳吸收劑反應影響不大，碳酸鈉/活性碳的轉化率則會上升。加入二氧化硫時，吸收劑更快到達最終轉化率；二氧化硫濃度為1000ppm時，會使得碳酸化轉化率下降，但濃度降為500ppm時，則讓碳酸化轉化率上升。吸收劑反應轉化率隨著相對濕度的提高而增加。在相同反應條件下，碳酸鉀/活性碳吸收劑比碳酸鈉/活性碳吸收劑有較高的碳酸化轉化率與較低的亞硫酸化轉化率。廢氣中的二氧化硫濃度若在500ppm以下，將不至於降低碳酸鉀和碳酸鈉吸收二氧化碳的能力。

關鍵字

活性碳 ； 碳酸鉀 ； 碳酸鈉 ； 二氧化碳 ； 二氧化硫 ； 吸收 ； 碳酸化 ； 煙道氣

並列摘要

A differential fixed-bed reactor was employed to study the removal of CO2 from flue gas using K2CO3 and Na2CO3 supported on activated carbon under low temperature (60℃) and humid (50-90%RH) conditions. CO2 concentrations ranging from 0 to 50% and SO2 from 0 to 1000ppm were used.
With the presence of CO2 and SO2, K2CO3 was converted to KHCO3 and KHSO3, and Na2CO3 to NaHCO3 and Na2SO3. When the sorbents reacted with CO2 alone, the increase in CO2 concentration had almost no effect on the conversion of K2CO3, but increased the conversion of Na2CO3. When SO2 was added, CO2 captures for both sorbents were decreased at the SO2 concentration of 1000ppm, but increased at 500ppm; the reaction of sorbents also reached the ultimate conversions more quickly than the CO2 alone case. The ultimate conversion of sorbents increased, as the relative humidity increased. Under the same reaction conditions, the extent of carbonation of K2CO3 was higher than that of Na2CO3, but the extent of sulfation of K2CO3 was lower than that of Na2CO3. The CO2 capture capacity of K2CO3 or Na2CO3 would not be reduced by the presence of SO2 in flue gas provided that the SO2 concentration is below 500ppm.

並列關鍵字

activated carbon ； K2CO3 ； Na2CO3 ； carbon dioxide ； sulfur dioxide ； absorption ； carbonation ； flue gas

參考文獻

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