本研究針對煙道氣中的揮發性有機化合物（volatile organic compounds，VOCs），以商業應用技術新型批次式觸媒法搭配火焰離子偵測器（gas chromatography/flame ionization detector，GC-FID），針對煙道氣中的非甲烷總碳氫化合物（total non-methane hydrocarbon，tNMHC），開發新型觸媒法開發連續自動監測系統（continuous emission monitoring systems，CEMS）。政府目前已公告NIEA A723.73B標準方法，作為空污費徵收的依據，因其採用CEMS，故具備準確、穩定且適合用於長期連續監測。此方法雖具備快速量測之優點，但在長期連續監測卻出現缺失，例如分析管柱使用分子篩，分析甲烷可能造成貫流或破出（breakthrough）效應，使NMHCs析出分子篩，導致高估甲烷濃度，低估tNMHC濃度；或分子篩完全堵塞，導致低估甲烷濃度，而高估tNMHC濃度等，因此，本研究計畫將採產學合作方式進行，由中央大學環境研究中心開發非連續間歇式（pulsed）進樣分析，使THC與tNMHC濃度訊號以出峰方式呈現，以避免觸媒長時間接觸污染氣體，大幅延長觸媒壽命，硬體機電設備開發由錦雲技術開發有限公司測試執行。本研究之成果同協助合作廠商解決關鍵技術方案，快速導入有機污染物自動即時監測技術與應用，衍生產業新價值。透過本計畫預計產出培訓碩士研究生共3名、完成1件具體且實際運用於合作企業之關鍵技術或產品、技術轉移1件及發表國際研討會期刊1篇。 ;The batch catalytic methods equipped with flame ionization detection (FID) were developed in this study to serve as continuous emission monitoring systems (CEMS) to measure volatile organic compounds (VOCs) in stack gas. CEMS is aimed at measuring the total amounts of non-methane hydrocarbons (dubbed tNMHCs) in stack gas. The method adopted packed columns and the back-flush design at isothermal oven temperature to separate methane from higher boiling VOCs. Within each analysis of 1 minutes, the concentrations of total hydrocarbons (THCs) and methane were alternatively obtained. Subsequently, the concentration of tNMHCs was obtained by subtracting the methane concentration from the THC concentration.The government has now announced the NIEA A723.73B standard method for the air pollution fee system. CEMS is accurate, stable and suitable for long-term continuous monitoring, but there are some disadvantage using this method on continuous monitoring: (1) Analysis of the column using molecular sieve , analysis of methane may cause a cross-flow or breakthrough effect, causing NMHCs to precipitate molecular sieve 5A. It causes overestimate methane concentration, and underestimate tNMHC concentration; or completely clogging molecular sieve . It causes in underestimation of methane concentration and overestimation of tNMHC concentration. (2) The role of molecular sieve in the original method should be called filter is not the analysis column, because continuous injection for a long time will cause NMHCs to accumulate on molecular sieve , but cannot be properly discharged, and once the high-boiling substance enters molecular sieve , it will cause it. There is enough time for the purification to accumulate inside the temperature (150 °C). (3) NIEA A723.73Buses two sample loops injection analysis. Although it is simultaneous sampling analysis, it may still cause errors in the calculation of non-methane hydrocarbon concentration because it is not the same sample. Therefore, this research project will develop a non-continuous pulsed injection analysis to make the THC and tNMHC concentration signals appear in a peak manner to avoid long-term exposure of the catalyst to polluting gases and greatly extend the life of the catalyst.
