- 學位論文
旋轉填充床中氫氧化鈉吸收二氧化碳 及苛化再生反應之改善
Carbon Dioxide Capture by Sodium Hydroxide in a Rotating Packed Bed and Improvement of Causticizing Regeneration Reaction
本文將於2025/07/03開放下載。若您希望在開放下載時收到通知，可將文章加入收藏。
摘要
由於工業發展致使大量排放二氧碳，進而導致溫室效應，這是近年不可忽視的議題，現今工業上最常用的吸收二氧化碳方法為透過醇胺吸收劑進行化學吸收，其優點在於吸收容量大以及反應速率快；而缺點則是吸收劑高黏度造成操作不易、所需設備體積龐大以及再生所需能耗較大，因此，除了吸收的效率外再生成本、效率也是一項考量因素。 故本實驗利用可以於室溫再生的氫氧化鈉為吸收劑，並使用旋轉填充床高質傳特性來提升吸收二氧化碳之能力，再利用氫氧化鈣來進行吸收劑之再生，達成RPB循環吸收/再生系統。本研究首先進行再生方法的改進，找出最佳的再生條件，再調整吸收條件，使吸收程序可以良好的搭配再生程序，設計出一個最佳的反應流程。在再生階段的研究分別進行再生溫度、氫氧化鈉濃度 、氫氧化鈣添加比例、 吸收時間 、 分次再生、調整溶劑、程序強化；而吸收方面分別進行吸收溫度 、 氫氧化鈉吸收劑濃度、 調整吸收劑、 液體流量 、氫氧根離子濃度與吸收百分比關係、Na2CO3濃度、吸收次數。 研究結果顯示，通過將旋轉填充床和旋轉盤相連，我們可以實現更高效的RPB循環吸收/再生系，使用旋轉填充床進行吸收，而旋轉盤進行再生。在此系統中，選擇了1L、0.9M濃度的氫氧化鈉作為吸收劑以維持80%吸收率以上為目標，在每次吸收20分鐘後進行再生有最佳的效果，同時，研究還顯示在55度的溫度下適量添加氫氧化鈣可獲得最佳的再生反應效果。在這樣的操作條件下，再生時間可以縮短至10分鐘，並且轉化率可以達到90%。 此外，通過這項研究還發現，Na2CO3的累積對吸收二氧化碳的效果具有負面影響。當氫氧化鈉重複循環15次後，二氧化碳的吸收百分比會降至80%以下。此時引入了硫酸銅作為添加物，將Na2CO3完全轉化為鹼式碳酸銅和二氧化碳，從而實現了商業應用的可能性。 這樣的操作流程實現了吸收劑的循環利用，不僅節省了資源和成本，同時也達到了低耗能、低污染、低水耗並有效捕捉二氧化碳的目標。這項研究為實現氫氧化鈉循環吸收和再生系統的優化，為未來的碳捕獲和利用技術的發展做出了貢獻。
並列摘要
Due to industrial development in recent years, a large amount of carbon dioxide emission causes the greenhouse effect that cannot be ignored. Currently, the most commonly used method to absorb carbon dioxide is by using alkanol amine solvents as the chemical absorbent. It has the advantages of high absorption efficiency and fast reaction rate; However, it also has drawbacks, including the high viscosity of the absorbent, large equipment size and high energy consumption required for absorbent regeneration. Therefore, in this study, a Rotating Packed Bed (RPB) of high mass transfer performance was adopted to capture CO2 with sodium hydroxide in a circulating mode. Then, the Ca(OH)2 was added for the absorbent regeneration, also called causticization. The research aimed to optimize the regeneration method by identifying the optimal process conditions of both absorption and regeneration. In the regeneration, the study was focused on the parameters of temperature, NaOH concentration, Ca(OH)2 addition ratio, absorption time, two-staged regeneration, solvent aditives, and process intensification by ultrasound or centeifual force. In the absorption, temperature, NaOH concentration, absorbent additves, liquid flow rate, the relationship between absorption percentage and hydroxide ion concentration, the concentration of Na2CO3, and absorption cycles. The results showed that by connecting the rotating packed bed and rotating disc, we could achieve an efficient RPB Circulating Absorption/Regeneration System. Absorption is performed using a rotating packed bed, while regeneration is carried out using a rotating disc. In this system, we selected 1L, 0.9M concentration of sodium hydroxide as the absorbent to ensure 80% and up absorption performance, and found that the optimal regeneration was achieved by regenerate the absorbent after 20 minutes absorption. The study also revealed that the best regeneration temperature was 55oC at which 90% conversion was obtained in 10 mins. Furthermore, it was observed that the accumulation of sodium carbonate had a negative impact on CO2 absorption efficiency. After 15 cycles of sodium hydroxide circulation, the CO2 absorption percentage could not maintain above 80%. To address this issue, copper sulfate was added as it to fully convert Na2CO3 into Cu2(OH)2CO3 that could be serve as a precursor for CuO. In this study, an absorption/regeneration process incorporating RPB/SDR was presented and investigated. It could successfully capture CO2 emission and achieve the goals of low energy consumption, low pollution, low water consumption.
參考文獻
Abanades, J. C. (2002). The maximum capture efficiency of CO2 using a carbonation/calcination cycle of CaO/CaCO3. Chemical Engineering Journal, 90(3), 303-306.
Adewole, J. K., Ahmad, A. L., Ismail, S., & Leo, C. P. (2013). Current challenges in membrane separation of CO2 from natural gas: A review. International Journal of Greenhouse Gas Control, 17, 46-65.
Alper, E. (1990). Reaction mechanism and kinetics of aqueous solutions of 2-amino-2-methyl-1-propanol and carbon dioxide. Industrial & Engineering Chemistry Research, 29(8), 1725-1728.
Anwar, M. N., Fayyaz, A., Sohail, N. F., Khokhar, M. F., Baqar, M., Yasar, A., Rasool, K., Nazir, A., Raja, M. U. F., Rehan, M., Aghbashlo, M., Tabatabaei, M., & Nizami, A. S. (2020). CO2 utilization: Turning greenhouse gas into fuels and valuable products. Journal of Environmental Management, 260, 110059.
Arabi, N., Jauberthie, R., Chelghoum, N., & Molez, L. (2015). Formation of CSH in calcium hydroxide–blast furnace slag–quartz–water system in autoclaving conditions. Advances in Cement Research, 27(3), 153-162.