标题: 以连续式电去离子单元应用于超纯水系统
Application of a continuous electrodeionization (EDI) unit in the ultra-pure water system
作者: 罗光照
黄志彬
Lo, Kuang-Chao
Huang, Chih-Pin
工学院永续环境科技学程
关键字: 连续式电去离子单元;离子交换;树脂再生;Electrodeionization (EDI);Ion exchange;Resin regeneration
公开日期: 2018
摘要: 超纯水系统是现今工业制程所需之必要系统,无论是半导体业、面板业、电子级化工、精密工业都需要使用大量的超纯水;但高洁净的超纯水在制造过程中却带来许多的能耗与药品的排放,可说是不环保但又必须高度需要的系统。因此如何削减超纯水系统的药品使用量与减少超纯水系统中废水的排放是本次研究的主要目的。
本研究是利用连续式电去离子单元与二段式逆渗透单元取代原超纯水系统阳离子树脂塔、阴离子树脂塔、混床树脂塔。并以实厂为例,在不影响既设系统水质、水量、下进行,并对既有树脂塔单元进行改造前的水质分析与改造后的水质比对最终再进行运转成本分析之差异研究。
连续式电去离子单元与阳离子树脂塔、阴离子树脂塔、混床树脂塔(mixed bed)最大不同之处为连续式电去离子单元是利用电再生方式以达到再生之目的,使用连续式电去离子单元不需要设置酸硷药品槽、酸硷药品再生泵、再生水塔槽,所以就系统空间配置上本研究发现在以连续式电去离子单元取代传统树脂塔后可以多出原传统树脂再生系统65% 的空间,就空间而言更为节省。
安装连续式电去离子单元后分析产水之比阻抗值为>18 MΩ.cm (at 25℃)、阴离子为<1 μg/L 、金属离子为<1 μg/L,均可以达到原有系统设计之功能,并在硼离子与二氧化矽去除率上面亦得到良好的去除率。运转成本为若使用阳离子树脂塔、阴离子树脂塔、混床树脂塔单元处理的成本为5.6元/M3使用连续式电去离子单元为4.9元/M3 ,以长期运转来看使用连续式电去离子单元取代传统树脂单元的超纯水系统设置相信是未来的趋势。
All pure water system is a necessary system in the current industry, including semi-conductor, panel industry, electric related chemical industry and fine-tuned mechanism industry, they all need large quantity of pure water involved, However, the highly pure water comes along with energy consumption and medicine related chemical emission problems that is not only environment unfriendly but also highly being needed to run the system, therefore, how to reduce the quantity of chemicals usage and waste water emission is the purpose of this study.
The study is using a continuous electro-deionization (EDI) unit and two-pass RO unit to replace cation tower, anions tower and mixed-bed, taking on the site factory for example, under the conditions of non-affection to the current water quality and quantity set by the system, carrying out water quality analysis and making cross check the water quality between transformation and transformation of the current resin tower unit.
That of the major difference of continuous EDI unit with the cation/anions/mixed-bed towers is the regeneration method. Moreover, using the continuous EDI unit does not require to install chemical storage tanks, regeneration pumps, and regeneration tanks, as to the space arrangement concerned, the study revealed after using the continuous EDI unit to replace the traditional resin tower, there will be 65% more space available left, compared to that of conventional resin regeneration system, as far as the space placement concerned, that is much more cost saving.
After installing the continuous EDI unit, water quality for resistivity is higher than 8MΩ.cm (at 25℃), anions concentration is less than 1 μg/L, metal ion concentration is less than 1 μg/L. Those changes can achieve the originally designed function of the system as well as have a good cleaning rate on the aspect of boron and silica. As for the operation cost concerned, the management cost of using the cation tower, anions tower and mixed-bed is 5.6 NT dollars /m3, however, using the continuous EDI unit only stands 4.9 dollars/m3, as far as long running operation concerned, using the continuous EDI unit to replace the traditional resin tower unit concerning the installing of all pure water systems, we deeply believe that will be a foreseeable trend in the future.
URI: http://etd.lib.nctu.edu.tw/cdrfb3/record/nctu/#GT070261507
http://hdl.handle.net/11536/142937
显示于类别:Thesis