| 摘要: | 膠帶製造業為國內重要的傳統產業，總產量僅次於美國及義大利，居全球第三名，但於生產之上膠塗布烘乾過程中，揮發性有機物（VOCs）易逸散形成空氣污染物；根據行政院環保署之统計，台灣地區膠帶製造業VOCs總排放量每年約29,500公噸，佔台灣地區固定污染源總排放比率約9.0％，為國內重要之VOCs排放源。 本研究係針對膠帶製造廠進行VOCs排放與防制之探討，分別於96年及97年，針對其二套活性碳污染防制設備之前後，各進行2次總碳氫化合物之檢測作業，並記錄該廠之產能與操作條件，以探討膠帶製造業VOC排放與活性碳吸附系統之處理效率。經分析結果顯示，該廠VOC排放係數（含煙道與逸散）為0.011（kg/m2），接近環保署VOC空污費徵收公告之排放係數0.009 kg/m2；或是0.184（kg-VOC/kg-溶劑），略高於美國之0.10~0.15（kg-VOC/kg-溶劑）。 研究結果發現；上膠機之集氣效率為82.58%，低於美國AP-42設定之90~95%，亦即約有二成VOC未被收集而逸散至環境中；但活性碳吸附系統之處理效率可高達98.84%，高於我國法規要求之90%以及美國要求之95%，顯示國內膠帶業活性碳回收系統之設計與操作技術已臻成熟。整廠甲苯回收率僅為75%，主要是上膠機未收集完全而逸散者，此外尚有甲苯貯存與調製作業時所逸散、殘留於產品中以及活性碳脫附時排入廢水者。 在VOC處理技術方面，不管就處理效率、經濟效益或環境效益之觀點，活性碳回收是膠帶業界最佳的處理技術，其處理效率可達98%以上，回收之溶劑可重複使用或出售，達到節能減碳之目的；二套活性碳設備之年操作維護費用為新台幣1,379萬元，回收之甲苯價值3,122萬元，每年有1,743萬元之收益；另環境效益方面，每年尚可減少CO2排放量約3,121公噸，效益極為顯著。 上膠機之集氣效率偏低是目前業界有待努力的方向，上膠機設置圍封式集氣系統是環保主管機關即將要求的設施；另水性、高固型份與熱熔性黏膠亦是本產業未來發展的方向，但由於生產線必須加以調整，近期內業界採行之意願可能不高。 Pressure sensitive tape production is an important traditional industry in Taiwan, whose grand output is the third place in the world, only next to U.S.A. and Italy. However, some VOCs are emitted from the drying process of glue coating and this issue needs to be addressed from the considerations of workers’ safety and environmental protection. The statistics released from Taiwan Environmental Protection Agency indicate that the annual VOC emissions from pressure sensitive tape manufacturing industry is around 29,500 tons, which accounts for approximately 9% of the total VOC emission from stationary sources in Taiwan, and the tape industry is regarded as one of the the major sources of VOCs. This research aims to analyze the control efficiency of the activated carbon adsorption systems applied in Plant A for VOC recovery and to compile the VOC emission factors from a typical pressure tape manufacturing process via intensive sampling and analysis of total hydrocarbon emissions conducted in 2007 and 2008. Additionally, the output capacity and operating conditions of the Plant A during the sampling duration are also recorded. The VOC emission factor (including stack and fugitive emissions) is 0.011 kg-VOCs/m2-product, which is close to the emission factor of 0.009 kg-VOCs/m2-product as recommended by Taiwan EPA. Another VOC emission factor is determined as 0.184 kg-VOC/kg-solvent, which is a little higher than 0.10~0.15 kg-VOC/kg-solvent as recommended by USEPA. The overall VOC capture efficiency of the coating line is 82.6%, which is far below 90~95% regulated by AP-42. Nearly 20% of the solvent input escaped from the VOC capture and control devices, while the adsorption efficiency of the activated carbon systems reaches 98.84%, which is greater than the standard as required by Taiwan EPA (90%) or the standard regulated by USEPA (95%). The high VOC adsorption efficiency achieved with Plant A indicates that the application of an activated carbon adsorption system for recovering VOCs from tape industry is appropriate and the technology is mature and well-developed. However, the recovery of toluene from Plant A is just 75% due to the incomplete capture, the residual on products and some loss to the wastewater during the desorption and condensation process. Activated carbon adsorption is one of the best technologies for recovering VOCs from the pressure sensitive tape manufacturing industry in terms of adsorption efficiency as well as economic benefits. The recovered solvent can be reused or sold to save energy and also reduce the carbon dioxide emission. The annual maintenance fee for two activated carbon adsorption systems applied in Plant A is estimated as NTD 13.8 million, while the annual income from toluene recovery reaches NTD 31.2 million. Not only an yearly revenue of NTD 17.4 million can be generated, but also 3,121 tons of CO2 emission can be reduced annually by applying this activated carbon adsorption system. For further reduction of the VOC emissions, an enclosure type coating system should be applied and the operating parameters of the activated carbon adsorption system should be optimized. |
