EPA-94-U1U1-04-011

094

3,995 千元

2005/03/04

2005/12/31

台灣科技大學　顧洋

永續發展室(停用)

國立台灣科技大學化工系　顧洋、李嘉平

水質保護

光電與半導體產業，臭氧，高重力旋轉填充床，質傳係數，轉速

ozone, rotating packed bed(RPB), isopropyl alcohol(IPA), kLa, TFT-LCD, automation

台灣科技大學　李嘉平、立曄股份有限公司　王文

國立台灣科技大學創新育成中心

02-27336797

saball@mail.ntust.edu.tw

現行之光電與半導體產業對產品製程之潔淨度要求甚嚴，故大量採用特定之化學品進行處理，再以大量純水進行清洗，此為本類產業為人詬病之環境考量之一。有鑑於管末處理對製程之重要性，且現有之廢水處理大多以生物法為主，但對於具多成分且中低濃度之光電業廢水而言，目前面臨較為急迫者為清洗製程大量產生之含異丙醇(IPA)廢水，傳統之生物降解易產生多種有機代謝物，如丙酮及有機酸等，不易控制處理效率。尤其在有機廢水部分，考慮工安問題及廢水之濃縮與流佈，傳統燃燒法及再生使用之效益不高。而從水資源回收的觀點而言，中低濃度之異丙醇(IPA)廢水，其污染物種類少，水體負荷低，也較易於進行水回收。 在考量光電產業廢水處理之成本居高不下以及污染防治設備之設置與維護保養負擔，本育成計畫擬利用高重力式之旋轉填充床，配合進行臭氧對有機廢水之強制性質傳與氧化程序，開發適用於光電製程現場之廢水處理設備單元。擬開發之設備乃藉由臭氧之高氧化能力，將製程廢水中之有機物氧化分解，同時透過旋轉填充床之高質傳特性，克服以往臭氧程序因溶解度不足而無法有效處理大量廢水之窘境，且因臭氧利用率提升，能於製程現場及時將廢水分解並減少尾氣臭氧濃度，進而降低操作成本且免於臭氧廢氣之後處理。 從測試結果得知，由實驗結果顯示，以鐵氟龍氣密軸封配合軸承與變頻馬達，可得到良好的高速旋轉效果，並達到超過800G的高重力環境。此外，根據臭氧質傳試驗分析得知，以較大的進氣流量及低氣液比(G/L=1.0-1.5)與高轉速(600-1800rpm)能造成較高的臭氧質傳係數(kLa= 0.588min-1)，促進水中的臭氧溶解速度達飽和平衡值。相較於其他臭氧質傳反應器，雖有較佳之質傳效果，但質傳面積卻相對偏低，推測是高重力環境可能影響質傳行為。而從實際進行異丙醇(IPA)有機廢水的臭氧分解實驗結果發現，在中低濃度範圍下(異丙醇<100mg/L)，本計畫所開發之高重力旋轉填充床氧化系統能有效地將異丙醇(IPA)及其中間產物(丙酮及醋酸)有效分解，並克服以往臭氧程序在臭氧利用率以及處理量上的障礙，在模場測試中，單機每日處理量可達70噸。而根據成本分析，以本設備從事異丙醇(IPA)廢水的處理，設備成本約為175萬元，單機運轉時可將處理費用降至35元/噸，並能直接進行管末排放或進入水回收再利用程序。另對於中高濃度異丙醇(IPA)廢水(250-20,000mg/L)之處理，則可藉由單機設備之串並聯運轉設計及回流反應系統的架設，達到快速且有效的運轉效能。

光電與半導體產業，臭氧，高重力旋轉填充床，質傳係數，轉速

EPA-94-U1U1-04-011.pdf

4MB

[期末報告]公開完整版

2006/3/1 上午 12:00:00

The ozonation of isopropyl alcohol (IPA) wastewater from TFT-LCD wet process using a rotating packed bed reactor (RPB) was investigated in this study. Various rotor speed, flow rate ratio of gas to liquid, ozone gas concentration, and the vibration and noise were investigated to realize the effect on the gas-liquid contacting and the stability of rotating packed bed operation process. Heat generation of sealing was eliminated by water flow and the pressure drop of the reactor opposite to atmosphere was up to 2.5 kg/cm2. Vibration of the RPB in horizontal direction is much greater then in vertical direction possible due to the parallel spinning of rotor to horizontal surface. The noise of RPB during the operation was increase with rotor speed, which means that the friction in RPB was not tuned well. Automation equipment couple special sensor and PID controller were set up for pilot run and process scale up. Also, the various level of organic wastewater could be treated in this project to evaluate the potential of RPB in wastewater treatment, especially in TFT-LCD and semiconductor manufacturing. In this study, isopropyl alcohol (IPA) removal degree was defined from the observed data and employed to quantify the treating efficiency of ozonation process in rotating packed bed reactor. When rotor speed was controlled at 1800 rpm with mean acceleration rate of 5233 m/s2 (543G) at radius of 0.15m, the liquid film was thinner and interface renewal on pall rings was more rapid in a rotating packed bed reactor. Experimental results indicated that kLa for the rotating packed bed reactor was four-fold of kLa for the referenced packed bed reactor. The kLa for the rotating packed bed reactor was proportional to 0.15 order of rotor speed and increased with decreasing flow rate ratio of gas to liquid, simultaneously. RPB with larger disk radius and higher rotor speed could create a special environment with extremely high gravity, in where, the property of water and ozone molecules might change and phase equilibrium behavior was un-predictable. During the operation of RPB, the isopropyl alcohol (IPA) wastewater in the range of 0.5 to 100mg/l were completely removal by ozone process and the operating cost was estimated about 35 NT$/ton. The total cost of RPB with other utilities for pilot run was also controlled at the limit of 1.75 million NT$. Treating of high level isopropyl alcohol (IPA) (200-20,000 mg/l), a matrix of RPB reactor with serial and parallel connection will achieve higher capability of wastewater treatment and water recovery. Further examination of RPB and the performance of organic wastewater removal by ozone process with RPB were undergoing.

ozone, rotating packed bed(RPB), isopropyl alcohol(IPA), kLa, TFT-LCD, automation