現今溫室氣體排放增加，造成全球平均溫度也逐年增加，各地氣候異常頻傳，減少大氣中的溫室氣體─二氧化碳含量是近年來相當重要且極需解決的議題，目前二氧化碳封存被認為是能有效減少溫室氣體的方法之一。二氧化碳封存是將二氧化碳灌入到耗竭油氣田、深層鹽水層和煤層等地方，藉由岩體將二氧化碳吸附，保存在岩層中，以降低大氣中的二氧化碳量。台灣各地有許多廢棄的煤礦坑與含煤層，可以評估做為二氧化碳封存的目標區。本實驗目的是了解煤的材料特性對二氧化碳吸脫附能力的影響，預期可應用於煤層封存二氧化碳的參考。本研究採集6個台灣煤樣進行實驗，本實驗主要分為三部分，一是將煤樣粉碎至60 mesh，放置烘箱內(50℃)一天後，將煤樣放入儲煤瓶抽真空並逐步增加壓力至800psi，逐步減少壓力，觀察煤樣吸脫附和壓力改變之關係，再將二氧化吸附實驗所得的數據帶入 Langmuir Isotherms ，計算出煤樣Langmuir Volume Parameter（煤樣最大吸附氣體儲存能力），二是煤樣敲碎過篩，再加入黏合劑倒入圓形鋼模，經脫模拋光後，用反射光顯微鏡測量鏡煤素反射率(Ro%)並計算煤素質比例，三為求數據的多樣性，加入蕭健宏(2013) 20個台灣煤樣特性數據，將煤的Langmuir Volume參數和材料特性去做比對，找出這些因子之間的相關性。研究結果，二氧化碳吸附能力與煤級呈曲線關係，與鏡煤素含量呈正比，與礦物質含量呈反比。在因素分析中，綜合所有煤樣特性分析下，由於特性之間互相影響，故實際能分析可用數據為19個，而分析結果為VL、PL、平均孔徑、水分與氣體吸脫附能力之相關性較佳。;Greenhouse gas emission contributes to global warming and abnormal weather conditions. In recent years, how to reduce carbon dioxide quantity in the atmosphere is an important environmental issue. Geological sequestration of CO2 is considered to be an effective way of reducing greenhouse gas in the atmosphere. Possible sequestration sites include depleted oil reservoir, saline aquifer and unmineable coal seam. The purpose of this study is to evaluate the effects of coal characteristics upon the ad/desorption of CO2. A total of six coal samples were collected, and the experiment was divided into three parts (1) Coal samples were crushed to < 250μm, and then placed in a drying oven at 50 ℃ for a day, put coal samples into a sample vessel and gradually increase the pressure to 800psi, and then progressively reduce the pressure. Adsorbed and desorbrd CO2 under various pressure were recorded. The CO2 ad/desorption data were then analyzed by Langmuir Isotherms to calculate Langmuir Volume Parameter (maximum adsorption coal gas storage capacity, VL); (2) Coal samples were made into pellts to measure their vitrinite reflectance and maceral composition under reflected light microscope; (3) Combined with coal data from Shaw (2012), Lamgmuir Volume parameters can be correlated among various factors. The results showed that adsorption of CO2 exhibits a curved relationship with coal rank, positively correlated with vitrinite content, and negatively correlated with mineral matter content. As for factor analysis, the influence of characteristics among each other can be analyzed for 19 available sets of data.The results indicate VL, PL, average pore size, and moisture exhibit good correlation with ad/desorption of CO2.
