- 學位論文
以還原碴廢棄材料捕捉二氧化碳之研究
Carbon dioxide capture by waste material of reductive slag
摘要
本研究目的以還原碴廢棄材料捕捉二氧化碳，評估碳酸化效率、反應速率及反應機制。試驗中在不同的操作條件下，分別進行於氣液相系統及氣液固相系統。 萃取試驗結果指出，在pH值為4及固液比50 g/L 時，鈣離子最大萃取效率79.4%。氣液相系統於氣體流量1.0 L/min 及二氧化碳進流濃度100%下反應60分鐘，達最佳碳酸化效率67.6%。 此外，氣液固相碳酸化試驗結果顯示，在固液比30 g/L、氣體流量1.0 L/min、二氧化碳進流濃度20%下反應90分鐘，達最佳鈣轉化率51.3%。經動力模式模擬氣液固相碳酸化反應相當符合表面覆蓋模式，並由動力分析得知碳酸化反應速率常數隨氣體流量與二氧化碳進流濃度的增加及固液比的降低而增加。
並列摘要
The objectives of this study were to evaluate the carbonation efficiencies, reaction rate and mechanism for carbon dioxide capture by waste material of reductive slag. The experiments were carried out at gas-liquid phase system and gas-liquid-solid phase system under different operation parameters, respectively. The results of extraction tests indicated that the maximum 79.4% of calcium was extracted from slag at pH 4 and solid/liquid ratio of 50 g/L. Then, the optimum 67.6% carbonation efficiency was obtained at gas flow rate of 0.5 L/min and inflow CO2 concentration of 100% during the 60 min reaction time for gas-liquid phase system. In addition, the test results of gas-liquid-solid phase system revealed that the optimum calcium conversion was about 51.3% at the conditions of solid-liquid ratio was 30 g/L, gas flow rate was 1 L/min, and inflow CO2 concentration was 20% during the reaction time of 90 min. The result of simulation kinetic studies showed that the carbonation reaction occurred in gas-liquid-solid phase system was well fitted to the surface coverage model. Also, the reaction rate constant of carbonation was increased with the increase of gas flow rate and CO2 concentration, and with the decrease of solid-liquid ratio, respectively.