沸石濃縮轉輪與蓄熱式燃燒爐之瓦斯節能操作探討-以TFT-LCD廠為例

Abstract

摘 要 光電產業中的TFT-LCD (Thin Film Transistor Liquid Crystal Display；TFT LCD)產業製造過程所產生的揮發性有機物VOCs(Volatile Organic Compounds，VOCs)特點為高風量、低濃度，國內科技工業多以沸石濃縮轉輪搭配焚化系統來處理此類製程廢氣，而其燃料多以天然氣為主，國內天然氣來源主要以進口方式取得，且天然氣價格有日益上升的趨勢，增加了處理設備的運轉成本。 本研究針對沸石轉輪與蓄熱式燃燒爐於符合法規及最佳可行控制技術條件前提下，進行各項節能措施調整。其中熱能回收項目係利用TFT-LCD產業的製程機台之高溫排氣作為轉輪冷卻入口空氣使用，經導入測試後有提升轉輪脫附區出口溫度及節省瓦斯效果，實現節能、熱能再利用之目標，而熱能氣流含低濃度VOCs，將其導入轉輪中可減少其逸散於大氣環境中。針對實廠測試數據顯示，1台沸石濃縮轉輪與蓄熱式燃燒爐系統，調整後可節省之瓦斯度數為181,332 m3/year，節省金額為3,401,788 NTD/year，CO2排放量降低340,904 Kg/year，測試項目中以熱旁通風門調整效果最佳，其瓦斯節省比率佔總效益之51.2%；其餘調整參數項目：脫附風量、轉輪轉速、熱能回收、再生風溫及爐溫等，其瓦斯節省比率依序為20.5%、9.7%、6.8%、6.3 %及5.8%。

Abstract In thin film transistor liquid crystal display (TFT-LCD) manufacturing plants, the zeolite concentrator with an oxidation process worked by nature gas energy is one of the most popular methods to control volatile organic compounds exhaust that contains complicated components with high flow volume and low concentration. This study explores various energy saving zeolite concentrator and regenerative thermal oxidizer technologies to find out the optimized conditions for improving the energy conservation and reducing the cost under the current environmental regulations. The tested data of the “thermal energy recycle” adapted in this study indicate that the outlet temperature in the zeolite rotor concentrator desorption area has been effectively increased and the usage of nature gas has been decreased. The real fabrication plant test data show that a single zeolite concentrate rotor incineration system would reduce the total nature gas consumption by 181,332 m3 per year, cost saving of around NT 3,401,788 per year , and the CO2 emission reduction of 340,904 Kg per year. The data also suggest that the adjustment of the “hot gas bypass damper opening ” contributes to 51.2% of natural gas conservation which is the most significant adjustment parameters. Other adjustments of “desorption air flow”, “ratation speed”, “thermal energy recycle”, “desorption (regenration) temperature”, and “furnace temperature” account for the natural gas conservation rates of 20.3%, 9.7%, 6.8%, 6.3%, and 5.8%, respectively.