以石灰石製備鈣基複合材料之特性分析與中溫二氧化碳捕獲研究

Abstract

本研究選用天然礦物石灰石作為前驅物，以製備具有優異捕獲效能之中溫之二氧化碳捕獲劑。本研究主要分三大部分，第一部分：將醋酸酸化後之石灰石粉體以不同比例之金屬離子進行結構及捕碳效能改質，並以XRD及SEM觀察其相變化及粉體形貌之轉變。爾後，將於450°C進行二氧化碳捕獲，最佳之樣品乃具有最高63.3wt%之捕獲量，但經20個循環迴圈後其捕獲維持率則為36%。 第二部份的研究，則進一步利用第一部份研製之捕獲劑，煅燒後以修飾劑修飾。經由TGA測試二氧化碳捕獲結果指出修飾後之捕獲劑，首個循環迴圈捕獲量高達58.5wt%，而經20個循環後其循環迴圈捕獲量維持率仍具67%，此結果顯示經修飾劑改質之捕獲劑乃具有提升捕獲穩定性之顯著效能。 本研究之最後探討，則將前述研製之捕獲劑，應用於固定床反應器。除此之外，亦將產生捕獲效能劣化之捕獲劑粉體進行兩種不同之粉體再生程序，並觀察其對於二氧化碳捕獲之影響。

In this study, we chose limestone as the source of CaO-based CO2 sorbent, which is a promising material for CO2 capture at medium temperature. In the first part of this study, we added different amount of metal ion into acetified limestone to investigate the phase and morphology change by XRD and SEM. The highest CO2 capacity is 63.3wt% at 450°C. In the second part, we developed a promoted sorbent by adding promoter into the calcined powder. The TGA results indicated that the 1st-cycle capacity of promoted sorbent was 58.5wt%. After 20 carbonation-calcination cycles the CO2 capacity can retain 67% of its initial capacity, higher than 36% of the sorbent without modification. The last part of this study was to examine the CO2 sorption capacity of the sorbent in the fixed-bed reactor. Furthermore, we investigated two kinds of regeneration method to reactivate the spent sorbent.