應用微波電漿技術資源化廢棄電路板中的樹脂

Application of atmospheric microwave plasma on vitrification of resin from the PCB Waste

杜恩臨(Raynard Christianson Sanito)

指導教授 ： 王雅玢

共同指導教授 ： 游勝傑(Sheng-Jie You)

中原大學/工學院/土木工程研究所/博士(2021年)

https://doi.org/10.6840/cycu202100220

摘要

電漿技術在環境廢棄物處理的應用相當廣泛，尤其是在處理廢棄物中的有害物質。然而，在使用助熔劑進行玻璃化的應用時，電漿技術因為能耗高而使得處理費用相對昂貴，但對於難處理的廢棄物，如何在成本效益的考量下，找到一個適用於電漿技術的低成本助熔劑，實現循環經濟理念是非常重要的。
本研究針對微波電漿系統，利用鳳螺、九孔、豬骨、牛骨以及雞骨等常見廢棄物製備低成本之助熔劑，並對此以及商用助熔劑進行特徵分析，評估去除PCB廢樹脂中的有害物質之效益，此外，實驗設計透過Taguchi方法獲得最佳之反應時間、微波功率、氣體流量、氣體種類以及助熔劑比，並進一步針對各參數進行更細部研究，且研究亦針對環境效益及經濟效益比較優劣勢及可行方案進行SWOT分析。除電子廢棄物外，研究也針對吸附了重金屬的水芙蓉以及布袋蓮等水生植物，進行微波電漿處理，並高值化成光觸媒的應用潛力進行研究。
實驗結果顯示，以混合貝殼粉末當助熔劑處理PCB廢樹脂，對廢樹脂衍生的苯以及甲苯其降解效率可分別達到98.8%以及100%，在添加較高比例貝殼粉末助熔劑的廢樹脂，其金屬以及類金屬的安定化性能達到96%，並在最終產物中產生碳酸鈣晶體，證實其對金屬及類金屬的固化功效。高含量的助熔劑(鳳螺、九孔、石英砂以及石灰石)以1：2比例添加到廢樹脂中，實驗結果顯示具有較佳的玻璃化效能，在成本的考量下，以食物廢棄物製成之助熔劑更具有經濟效益，應用SWOT分析低成本助熔劑的開發，共可獲得12種不同策略。此外，透過Taguchi試驗，使用1公克石英砂混合之樣品，在氮氣流量為9 LPM、微波功率為1200瓦特以及10分鐘的熱解實驗下，對鋅濃度可得最佳去除效率99.72% （0.21 ppm)，顯示最佳反應時間為10分鐘，與其他實驗參數相比其更為關鍵因素。
對水芙蓉以及布袋蓮進行之電漿實驗結果顯示，砷、鎘、同、鉻、鈷、鎳、鉛以及鋅等元素去除效果很好，其濃度均小於1.4 ppm。其經過電漿處理後製成活性碳在酸性藍的吸附實驗結果顯示，其可達到175.57 mg / g的降解效率，添加雞骨廢料和經過電漿處理後製成的活性炭，降解效率分別為139.41 mg / g和142.23 mg / g。在可見光之光催化實驗下，摻有雞骨廢料和豬骨的光觸媒，對氮氧化物的去處效率分別達到81％和63.3％。以微波電漿設備利用豬骨廢材所製成之助熔劑協助處理PCB廢樹脂，最終產物的成分分析顯示，使用8 mol/L的硫酸可以從廢PCB中回收700 mg/L的銅，從廢樹脂中回收4720 mg/L的鋅，因此，雞/豬骨與石英砂和玻璃/碎玻璃的結合顯示其對廢樹脂和PCB的玻璃化具有優異的效能。
綜合上述，以微波電漿設備添加低成本之助熔劑，在廢樹脂的玻璃化、安定化以及稀有元素的回收均有不錯的成效，透過合適的策略選擇可實際應用於實場中。另外，樣品添加貝殼粉末以及廢骨廢料的助熔劑，經過電漿再處理後，殘留物可再利用於吸附和光催化反應，符合循環經濟之理念。

關鍵字

吸附 ； 光催化劑 ； 循環經濟 ； 助熔劑 ； 惰性化 ； 安定化 ； 微波電漿 ； 樹脂 ； 玻璃化

並列摘要

Plasma technology has been used widely for the environmental applications and environmental clean-up, especially to eliminate the harmful elements and vitrify the materials via the ionization from plasma discharged, Recently, however, the using of plasma technology, which consume a lot of energy, is an expensive technology as well as the flux agent to vitrify the material. Therefore, the finding of the cost-less flux agents for vitrification and inertization of pollutants, calculation of technology based on the economic perspectives, development of strategies, selection of proper technology for the reusing the material from plasma post-treatment for fulfill the concept of circular economy are necessary to be performed.
In this dissertation, cost-less flux agents, namely, shells powder from Babylonia formosae and Haliothis diversicolor, and bone powder from pork and chicken bone waste, obtained from food wastes were prepared, characterized, performed and compared with the commercial flux agents on the removal of harmful elements using an atmospheric pressure microwave plasma reactor to deal with resin from printed circuit board (PCB) waste (e-waste). Moreover, the quantitative and qualitative studies of environmental evaluation and environmental economic were formulated to develop the strategies to apply this material in the real application as a cost-less flux agent based on the SWOT analysis. To obtain proper parameters in an atmospheric-pressure microwave plasma reactor: pyrolysis duration, microwave power, gas flow rate, gas types and flux agent ratio were assessed via a Taguchi Method. Also, the special focus on the parameters, such as crucible distance and addition of quartz sands, were assessed. Lastly, the elimination elements from hyper-accumulator plants (Water hyacinth and Water lettuce) and its potential as an activated carbon was conducted, and the residue from plasma post-treatment, chicken bone waste, and pork bone waste were tested in the adsorption and photocatalyst application.
The fuse of shell powder shows an efficiency removal of benzene and toluene at value 98.8% and 100 %, respectively. Then, the higher ratio of shell powder improves inertization of metals and metalloids more than 96%. Calcite formation (CaCO3) can be found in the final residue, confirming the degradation of metals and metalloids. The addition of higher ratio of flux agents (Babylonia formosae, Haliothis diversicolor, quartz sand and limestone) compared to samples (1:2) shows a good vitrification, and it is supported by the closer position of crucible to the plasma jet discharged. Based on the economic perspectives, flux agents from food waste may tackle the cost issues in plasma technology. Also, there are 12 strategies that may be formulated derived from SWOT analysis based on the external and internal condition in the development of cost-less flux agent. Then, Taguchi methods confirmed that nitrogen gas with 9 L/min of gas flow rate, the fuse of 1 g quartz sand from the sample, pyrolysis in 10 minutes and 1200 watt of microwave power with the lowest concentration of Zn was 0.21 mg/L (99.72%). The most important factor for plasma pyrolysis was 10 minutes of duration, which indicated the greater result compared to other parameters.
The treatments of Water hyacinth and Water lettuce indicate a good removal of elements (As, Cd, Cu, Cr, Co, Ni, Pb, and Zn) with the value less than 1.4 mg/L. Activated carbon derived from water hyacinth from plasma post-treatment indicated the maximum capacity with the value at 175.57 mg/g, and the adsorption occurs at the monolayer condition in the acid blue. In the experiment of activated carbon derived from chicken bone waste and from plasma post-treatment were 139.41 mg/g and 142.23 mg/g, respectively. For the photocatalyst test, TiO2 doped with chicken bone waste and pork bone removes 81% and 63.3% of NOx, under the solar light irradiation. Lastly, the atmospheric-pressure microwave plasma reactor combined with the pork bone indicates good results to decrease the concentration of As and Pb from PCB were 37.30% and 2.58%., respectively. Furthermore, 700 mg/L of Cu from PCB and 4720 mg/L of Zn from resin can be recovered using the leaching with 8 mol/L H2SO4, and chicken bone/pork bone combined with quartz sand and glass/cullet indicates a proper vitrification of resin and PCB.
To summarize, the addition of cost-less flux agents shows a promising result on the vitrification, inertization of elements and recovery of precious elements in an atmospheric-pressure microwave plasma reactor, and potentially may be applied in the environmental applications ith the proper strategies. In addition, the material from plasma-post treatment with the presence of flux agents from shell powder and bone wastes may be reused to the in the adsorption and photocatalyst application, and fulfill the concept of circular economy.

並列關鍵字

Adsorption ； photocatalyst ； circular economy ； flux agents ； inertization ； microwave plasma reactor ； resin ； vitrification

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