Alkali Adsorbent for Removing Acidic Exhaust from Semiconductor Process

摘 要半導體業製程中產生無機酸性氣體具有低濃度與高流量之特性，而現階段的工廠中有九成以上都是以洗滌塔處理該氣體。但以洗滌塔去除效率不高且不易達到法規之要求。為解決此一問題，本研究利用鹼性吸附劑之設備來去除酸排氣。研究使用依吸附理論與規範設計出之小型固定床吸附塔及商用規格固定床吸附塔探討不同活性碳種類(AC-A為單純煤質活性碳，AC-B為含NaOH之煤質活性碳，AC-C為含KOH之煤質活性碳)與操作條件下對無機酸氣之吸附效能，藉以評選出適當之活性碳種類與得到最適操作參數。研究發現固定式活性碳床之壓損隨著空塔流速的增加而增加，其增加之速率呈拋物線向上增加。而含水率較高之活性碳，其壓損也隨之增加。對於酸性氣體( HCl, HF, H2SO4)而言，去除效率依序為AC-B, AC-C, AC-A。而AC-A對總碳氫化合物( total hydrocarbons, THCs)有良好之吸附能力。本研究之吸附塔經過1年實際運轉，結果顯示在固定床吸附系統使用鹼性吸附劑，可達到符合法規的標準且比洗滌塔吸收系統有更好的去除效率。Abstractn the semiconductor industry, the inorganic acidic gas emitted from the production processes has the characteristics with the low concentration and the high flow rate. In the present stage, over 90% factories treat this gas using the tower scrubbers. The removal efficiency of acidic gas of tower scrubber is not high, and sometimes may not easily meet the requirements of the laws and regulations. In order to solve for this problem, this study uses the alkaline absorbent to remove the acid exhaust.his research employed the small fixed bed absorption column and commercial fixed bed absorption column that are designed according to the adsorption theory and the standards. Three activated carbons (ACs) namely, the AC-A of the pure anthrax AC, AC-B of NaOH containing anthrax AC, AC-C of KOH containing anthrax AC, were used, at various operating conditions in the adsorption experiments. The suitabilities of activated carbons were evaluated to determine the proper operating parameters.he results indicate that the pressure loss (ΔP) of fixed activated carbon bed increases with the increase of superficial velocity (empty bed velocity). The value of ΔP also increases as the moisture content of AC increases.egarding the acidic gases (HCl, HF and H2SO4), the removal efficiencies from high to low are in the order of AC-B, AC-C and AC-A. However, the AC-A has the good adsorptive capacity regarding the total hydrocarbons (THCs). This research underwent one year plant operation. It shows that the fixed bed adsorption system using alkaline absorbent not only meets the laws and regulations standards, but also has the better removal efficiency compared to the tower scrubber absorption system.目錄試委員會審定書 謝 文摘要 文摘要 錄目錄目錄號說明 一章 緒論..............................................1 .1 研究緣起.............................................1.2 研究目的.............................................1二章 文獻回顧..........................................3.1 半導體製造業製程.....................................3.2 半導體製造業空氣污染物及排放標準.....................7.2.1 半導體製造業空氣污染物排放特性.....................7.2.1.1 煙道排氣中VOCs排放...............................7.2.1.2 煙道排氣中無機酸鹼污染物排放.....................8.2.1.3 製程中白煙排放...................................9.2.1.4 溫室效應氣體之排放...............................9.2.1.5 半導體廠內空氣污染物逸散.........................9.2.2 半導體製業空氣污染物排放標準......................11.3 活性碳特性..........................................12.4 吸附原理............................................32.4.1 吸附基本理論......................................32.4.2 等溫吸附方程式....................................32.4.2.1 Freundlich 等溫吸附方程式.......................33.4.2.2 Langmuir等溫吸附方程式..........................35.4.2.3 Dubinin-Radushkevich等溫吸附方程式..............35.4.2.4 BET多層吸附方程式...............................36.5 鹼性活性碳相關研究..................................36三章 實驗方法.........................................38.1研究流程.............................................38.2.實驗材料與設備......................................40.2.1 實驗材料..........................................40.2.1 實驗設備..........................................41.2.3 檢測方法..........................................44.3 實驗設計............................................45.3.1 小型固定床吸附系統................................45.3.2 商用規格固定床吸附系統............................48.4 吸附實驗之操作參數選定..............................51四章 結果與討論.......................................55.1 不同活性碳在固定式吸附床之流速與壓損之關係..........55.2 不同種類活性碳對酸性廢氣之去除效率..................58.3 相同空塔流速不同停留時間時，活性碳對酸性廢氣之去除效率......................................................73.4 最適之固定床吸附系統之操作參數......................90.5商用規格固定床吸附系統與洗滌塔之去除效率比較.........91五章 結論與建議......................................94 考文獻................................................96錄A 小型固定床實驗數據................................98錄B 半導體製造業空氣污染管制及排放標準...............118 目 錄2.1-1 半導體產業領域範圍...............................42.1-2 半導體廠製造流程圖...............................52.3-1 活性碳..........................................122.3-2 活性碳的孔洞分佈................................152.3-3活性碳之吸脫附能力...............................162.3-4 吸附處理流程....................................252.3-5 固定吸附床......................................262.3-6 角型吸附槽......................................272.3-7 流體化床吸附系統................................272.3-8 轉輪式的吸附系統................................282.3-9 吸附床的操作....................................292.3-10 商用活性碳再生流程.............................312.4-1 Brunauer五類等溫吸附曲線(W: Weight adsorbed, p: adsorbate equilibrium vapor pressure, p0: adsorbate saturated vapor pressure................................343.1-1 研究流程........................................393.3-1 小型固定床吸附系統流程..........................463.3-2 小型固定床吸附系統外觀圖........................473.3-3 商用規格固定床吸附系統流程圖....................493.3-4 商用規格固定床吸附系統流程圖....................504.1-1 活性碳ABC在不同流速之壓損.......................574.2-1 AC-A對不同酸性廢氣之去除效率...................594.2-2 AC-A對不同酸性廢氣之貫穿曲線...................604.2-3 AC-B對不同酸性廢氣之去除效率...................614.2-4 AC-B對不同酸性廢氣之貫穿曲線...................624.2-5 AC-C對不同酸性廢氣之去除效率...................634.2-6 AC-C對不同酸性廢氣之貫穿曲線...................644.2-7 不同活性碳對HCl之去除效率.......................654.2-8 不同活性碳對HCl之貫穿曲線.......................664.2-9 不同活性碳對HF之去除效率........................674.2-10 不同活性碳對HF之貫穿曲線.......................684.2-11 不同活性碳對H2SO4之去除效率....................694.2-12 不同活性碳對H2SO4之貫穿曲線....................704.2-13 不同活性碳對THC之去除效率......................714.2-14 不同活性碳對THC之貫穿曲線......................724.3-1 停留時間0.5秒之各種酸性氣體去除效率.............744.3-2 停留時間0.5秒之各種酸性氣體貫穿曲線.............754.3-3 停留時間0.75秒之各種酸性氣體去除效率............764.3-4 停留時間0.75秒之各種酸性氣體貫穿曲線............774.3-5 停留時間1.0秒之各種酸性氣體去除效率.............784.3-6 停留時間1.0秒之各種酸性氣體貫穿曲線.............794.3-7 停留時間1.25秒之各種酸性氣體去除效率............804.3-8 停留時間1.25秒之各種酸性氣體貫穿曲線............814.3-9 HCl在不同停留時間0.5-1.25秒之去除效率...........824.3-10 HCl在不同停留時間0.5-1.25秒之貫穿曲線..........834.3-11 HF在不同停留時間0.5-1.25秒之去除效率...........844.3-12 HF在不同停留時間0.5-1.25秒之貫穿曲線...........854.3-13 H2SO4在不同停留時間0.5-1.25秒之去除效率........864.3-14 H2SO4在不同停留時間0.5-1.25秒之貫穿曲線........874.3-15 THC在不同停留時間0.5-1.25秒之去除效率..........884.3-16 THC在不同停留時間0.5-1.25秒之貫穿曲線..........894.5-1 鹼性吸附系統與洗滌吸收系統每季檢測結果..........93 目 錄2.2-1 半導體產業污染特性一覽表.........................72.2-2 半導體製造業空氣污染物排放標準說明..............112.3-1 活性碳之特性....................................122.3-2 市售活性碳特性..................................132.3.3 活性碳對各種蒸氣之吸附能力......................172.3.4 氣相用活性碳參考規範............................202.3.5 一般水處理用粒狀活性碳參考規格..................222.3.6 工業用活性碳評估之項目及標準方法................232.3.7 吸附系統類型....................................252.4-1 物理性吸附與化學性吸附之差異....................324.1-1活性碳ABC在不同流速之壓損數據....................564.5-1鹼性吸附系統與洗滌吸收系統每季檢測數據...........5