利用轉爐石與鋼鐵廢水在漿體反應槽中進行碳酸化反應

Carbonation of Basic Oxygen-Furnace Slag with Metalworking Wastewater in a Slurry Reactor

邱安家(An-Chia Chiu)

指導教授 ： 蔣本基

國立臺灣大學/工學院/環境工程學研究所/碩士(2011年)

https://doi.org/10.6342/NTU.2011.02378

摘要

本研究針對中鋼鹼性固體廢棄物搭配中鋼廢水進行溼式碳酸化進行二氧化碳封存。鹼性固體廢棄物選用中鋼轉爐石，其成分含有大量的氧化鈣；中鋼廢水則是選用冷軋製程所產生的廢水和廢水處理場處理過後的放流水。
用泥漿反應器針對各種不同的操作參數進行實驗。為了不再額外增加能源消耗，不另外再針對實驗進行升溫或升壓。操作參數包含反應時間、不同水樣比較、液固比、氣體流量和反應體積。
實驗結果發現，在常溫常壓下反應時間2 小時，氣體流量控制在1LPM 且粒徑小於44μm 時，相較於放流水和自然水等其他水樣，冷軋水擁有較佳的轉化率約為89.19%。其反應過後的產物接附著在轉爐石表，故其整個反應的動力模式可以用「表面反應模式」進行推估，且其具有良好的廻歸，其R2 值都可以達到0.90 以上。
以3E(環境、工程、經濟)三種不同面相，針對五種不同情境與本土數據結合，進行不同衝擊類別下的量化工作。評估結果發現，本研究對於二氧化碳封存具有較為正面的效應，每封存1 公斤二氧化碳產生2.48 公斤二氧化碳，相較於文獻已經大幅下降，是一個新的里程碑。因使用的能源少資源少，對於環境衝擊降到最低，最經濟。故本研究確為可行的二氧化碳的減量技術。

關鍵字

二氧化碳封存 ； 濕式碳酸化 ； 流體化床 ； 生命週期評估

並列摘要

CO2 sequestration by basic oxygen slag in a slurry reactor containing metalworking wastewater was investigated in this study. There were two types of metalworking wastewater used in this study including effluent from metalworking wastewater treatment plant and cold-rolling wastewater.
The effect of operational conditions on the CO2 sequestration process were evaluated including the type of metalworking wastewater, reaction time, liquid to solid ratio and CO2 flow rate. The results indicated that basic oxygen slag in cold-rolling wastewater provided a better carbonation conversion approximate 89.18% at reaction time of 2 h, liquid to solid ratio of 20 and CO2 flow rate of 1
L/min. The developed surface coverage model for CO2 sequestration was used in this study to evaluate the carbonation conversion process. Although there were
insignificant differences between wastewater and tap water in carbonation conversion, reuse of metalworking wastewater as feedstock recycles the water resource and
reduces operational cost. It is a promising alternative for carbon sequestration.
On assessment aspect, the commercial value of CO2 sequestration technology by technical assessment was confirmed. LCA software, i.e., Umberto 5.5 is a useful tool
for environment analysis and quantifying the different environmental impact categories by combining international database, i.e., CML with interior statistics. The results indicate that the sequestration of aqueous carbonation by slurry reactor is more efficient than literature. Although it still has room to reduce CO2 emissions from experiment, this study is a feasible technique due to the highest conversion rate (89.18%) without extra consumption of energy and resources.

並列關鍵字

CO2 sequestration ； slag ； metalworking wastewater ； surface coverage model ； carbonation conversion ； slurry reactor ； LCA

參考文獻

[1] U. S. department of Commerce National Oceanic & Atmospheric Administration,

Miller, H.L., Contribution of working group I to the Fourth Assessment Report of

the Intergovernmental Panel on Climate Change, IPCC Fourth Assessment Report

greenhouse gas control technologies(GHCT) in Vancouver, BC, Canada, 5-9

September 2004.