回收廢電冰箱隔熱泡棉為環保產業之高端碳材

中文計畫名稱:回收廢電冰箱隔熱泡棉為環保產業之高端碳材

英文計畫名稱:Converting PU waste by hydrothermal carbonization to value-added carbon materials for environmental application.

契約編號:EPA-110-XB06

受補助單位:財團法人環境資源研究發展基金會

計畫主持人(包括協同主持人):林進榮 教授、楊志盛 副研究員

執行開始時間:110/01/01

執行結束時間:110/11/30

期末報告修正稿完成日期:110/12/02

報告總頁數:110頁

使用語文:中文,英文

中文摘要關鍵詞:水熱碳化、隔熱泡棉、活性碳、汞吸附

英文摘要關鍵詞:Hydrothermal carbonization, Polyurethane wastes, Activated carbon, Hg adsorption.

中文摘要
本研究提出回收廢電冰箱隔熱泡棉中的所含之碳、氮、和氟元素,轉製成含氮/氟活性碳,應用於燃燒尾氣中汞蒸氣的去除以及電容去離子器的電極材料,均為環境用途之高價碳材料。
前一期研究中,我們透過簡易的水熱法,接續活化處理將原本含氮量就很高的廢電冰箱隔熱泡棉直接轉化為含氮活性碳,用以吸附水中染料污染物以及電容電極碳材料,已證實具有高吸附容量與優良的電容特性。本研究關注氟氯氫化合物(HCFC)與環戊烷(CP)發泡劑的廢電冰箱隔熱泡棉,經水熱碳化反應及高溫活化作用,製得產物的物化特性與吸附能力的關聯性。同時,採用木材鋸末與廢電冰箱隔熱泡棉共水熱反應,以減少藥劑用量以及自衍壓力值,應用於汞蒸氣的吸附,以及實場運作電容去離子技術,評估其穩定性。
在期中報告進度中,透過木材鋸末與廢電冰箱隔熱泡棉共水熱反應,自衍壓力大多維持在<10 bar為主,活性碳整體產率為21%-43%。木材鋸末的添加可有效避免水熱碳產物沾黏的問題。FTIR圖譜與XPS圖譜均證實廢棄冰箱隔熱泡棉中的N與F元素,可有效保留在活性碳中。水熱碳化程序可有效促進礦物溶解,進而減少灰分值。商業活性碳FGD對汞的飽和吸附能力為4,570 μg/g。若是以木材鋸末為原料合成的活性碳對汞的吸附能力為5,045 μg/g。本研究轉製HCFC-PU與 CP-PU而得的活性碳對汞的吸附能力大於10,000 μg/g,高於商業活性碳FGD的飽和吸附量的2倍強。XAS圖譜擬合顯示汞化合物的組成比例,以HgNO3、Hg(NO3)2為主,故可以確定由廢舊冰箱泡棉轉製而得的活性碳內的N與F元素為吸附汞的重要元素。
在1 M之NaCl電解質溶液中,以掃描速度5 mV/s,活性碳材離子能有足夠的時間在特定的施加電位內擴散入活性碳孔洞內,最佳電容值為53.9 F/g。電容圖形均具有明顯的氧化/還原峰,代表含氮的官能基提供了一定的偽電容量,有助於提升整體的電容特性。實地電容測試的指標為鹽吸附容量2.84 mg/g,總量去除率41%,單位時間最佳去除率43%,單位碳電極重之平均吸鹽速率0.568 mg/g-min,電流效率111%,每噸水能耗0.261 kWh/m3,每莫耳吸鹽能耗0.100 kWh/mole,每克吸鹽能耗1.708 Wh/g-salt。
本研究可使這項傳統回收產業提升到新的應用材料領域,除了可減輕廢電冰箱隔熱泡棉對環境造成之衝擊外,亦可將廢電冰箱隔熱泡棉轉換為有用資源,變成附加價值高之產品,創造更高的效益。

英文摘要:
In this project, we used hydrothermal method instead of traditional pyrolysis to transform rigid PU waste into high-end activated carbon for capacitor and adsorption. We have investigated several factors to increase the adsorption capacity and to decrease the cost of chemicals and electrical power. Our experimental results indicated that the obtained activated carbon has 6% of nitrogen element and > 1,000 m2/g of specific surface area with 21%-43% production yield. In the Hg sorption experiment, the adsorption capacity was >10,000 g/g significant larger than that of commercial activated carbon FGD.
In a 1M NaCl electrolyte solution, at a scanning speed of 5 mV/s, the activated carbon material ions can have enough time to diffuse into the activated carbon pores within a specific applied potential, and the best capacitance value is 53.9 F/g. The capacitor patterns all have obvious oxidation/reduction peaks, which means that the nitrogen-containing functional groups provide a certain amount of pseudo capacitance, which helps to improve the overall capacitance characteristics. Field capacitance test indicators are salt adsorption capacity 2.84 mg/g, total removal rate 41%, best removal rate per unit time 43%, average salt absorption rate per unit weight of carbon electrode 0.568 mg/g-min, current efficiency 111%, The energy consumption per ton of water is 0.261 kWh/m3, the energy consumption per mole of salt absorption is 0.100 kWh/mole, and the energy consumption per gram of salt absorption is 1.708 Wh/g-salt.
This work not only reduces solid waste but also generates new resource. Further work will focus on the accreditation and certification of obtained products for wide applications in environmental-related field.