鋼鐵製程廢棄物應用於碳捕獲之績效評估及其再利用之潛勢分析

Assessment of Using Alkaline Wastes from Steelmaking Process for Carbon Capture and Resource Reutilization

潘述元(S. Y. Pan) ； 蔣本基(P. C. Chiang) ； 陳俊達(C. D. Chen) ； 林勳佑(H. Y. Lin)

《鑛冶：中國鑛冶工程學會會刊》 57卷3期 (2013/09) Pp. 75-84

https://doi.org/10.30069/MM.201309_57(3).0008

摘要

以超重力旋轉填充床進行轉爐石碳酸化捕獲二氧化碳之效率，較傳統反應器優越許多，且反應時間、溫度與壓力也較低；然而，此程序需研磨轉爐石，並使用額外能耗設備，因此將抵銷淨碳捕獲量。本研究嘗試結合鹼性冷軋廢水以提升單位爐石碳捕獲容量；同時，透過生命週期評估計算其淨捕碳效益；最後，透過電子顯微鏡與X光繞射分析，評估反應後轉爐石再利用潛力。結果顯示，冷軋廢水可以有效地提昇轉爐石中鈣離子之溶出，進而提升整體轉爐石捕獲容量。另一方面，反應後轉爐石生成大小約1-3 μm之立方體碳酸鈣（CaCO3）結晶於表面；此外，反應後轉爐石中free-CaO之含量完全消除。據此，本研究開發之碳捕獲程序可有效地於短時間內捕獲二氧化碳，同時將鹼性廢棄物安定化，並解決再利用遇到吸水膨脹之障礙。

關鍵字

轉爐石 ； 碳酸化 ； 旋轉填充床 ； 生命週期評估 ； 自由氧化鈣

並列摘要

CO2 capture by carbonation of basic oxygen furnace (BOF) slag in a rotating packed bed (PRB) is superior to that in the traditional reactors due to the relatively short reaction time at ambient temperature and pressure. However, grinding BOF slag and additional energy consumption are required to promote the overall carbonation efficiency for the RPB process. The coldrolling mill wastewater (CRMW) from the steelmaking process was utilized as the liquid phase to increase the carbonation efficiency and reduce the use of fresh resource. The net CO2 capture capacity of the process was evaluated by life cycle assessment (LCA). Results indicated that the CRMW could effectively enhance the dissolution of metal ions from BOF slag into solution, thus the CO2 capture capacity of BOF slag. The reaction product formed was mainly calcite (CaCO3) with particle size ranged between 1 and 3 μm. The content of free-CaO in BOF slag was found to be eliminated after carbonation. The RPB process could capture the CO2 from flue gas, neutralize the alkaline CRMW, and stabilize the BOF slag for further utilization.

並列關鍵字

basic oxygen furnace slag ； carbonation ； rotating packed bed ； life cycle assessment ； free-CaO