Modification of CaO materials to produce lamellar structure and its application as sorbent to high temperature CO2 capture procedure

出處 核研所 作者 郭奐廷 余慶聰 年份 2014
報告類型 國際期刊 分類 新/再生能源 |再生能源 資料時間 2017年12月

本研究利用改質氧化鈣製備碳捕捉材料,並比較醋酸鈣、氯化鈣等前驅物合成捕碳劑之CO2捕獲效果。醋酸鈣所獲得的材料表面積最大,而氯化鈣所獲得的材料的表面積較小。改質前CaO具有低表面積與較差的高溫捕碳穩定性,利用具有層狀結構之鈣鋁碳酸鹽進行CaO改質可顯著提升其捕捉特性。改質後CaO表面具有此層狀結構,經高溫煅燒形成多孔鈣鋁氧化物,因此促進材料的CO2捕獲性能。利用熱重分析儀測試捕碳性能,以醋酸鈣為前驅物所獲得的材料表現最佳,改質氧化鈣表現也相當優異,此二者捕碳性能皆優於氯化鈣衍生材料。其中以改質CaO獲得最佳結果,在750°C通入100% CO2條件,以TGA測試具有51.37 wt%的初始CO2捕捉量,40次吸脫附循環穩定性由50%提升至96.14%。本研究證實了以氧化鈣為前驅物合成碳捕捉材料並應用於高溫CO2捕獲反應的可行性。 In this study, a method of fabricating CO2 sorbents is developed, including calcium acetate (CA) and calcium chloride (CC) derived materials, and CaO modified (CM) sorbents. The nature of these sorbents was characterized by Brunauer-Emmett-Teller (BET) surface area analyzer and powder X-ray diffraction (XRD). BET analysis showed that the surface area of CA was higher than that of CC. The original CaO material exhibited disadvantages for CO2 capture performance at elevated temperature conditions, including low surface area and poor long-term stability. However, these defects can be significantly eased via modification of CaO to produce calcium aluminate carbonates with lamellar structure. XRD patterns indicated that fresh CM had a lamella structure, which became a porous calcium alumina mixed oxide after calcination and thus improved CO2 capture performance of sorbents. In TGA tests, both CA and CM displayed superior CO2 capture capacity compared to CC. Among them, CM is the best candidate for CO2 capture, demonstrating 51.37 wt% of capacity with high recovery of 96.14% maintained for 40 cycles at 100% CO2 and 750 °C conditions. The results confirm the potential for using low-cost CaO as a high-temperature CO2 sorbent.