Graduate Institute of Environmental Engineering, National Taiwan University, Taiwan.
Environ Sci Technol. 2013 Apr 2;47(7):3308-15. doi: 10.1021/es304975y. Epub 2013 Mar 18.
Both basic oxygen furnace (BOF) slag and cold-rolling wastewater (CRW) exhibiting highly alkaline characteristics require stabilization and neutralization prior to utilization and/or final disposal. Using CO2 from flue gases as the stabilizing and neutralizing agents could also diminish CO2 emissions. In this investigation, ex situ hot stove gas containing 30 vol% CO2 in the steelmaking process was captured by accelerated carbonation of BOF slag coupled with CRW in a rotating packed bed (RPB). The developed RPB process exhibits superior results, with significant CO2 removal efficiency (η) of 96-99% in flue gas achieved within a short reaction time of 1 min at 25 °C and 1 atm. Calcite (CaCO3) was identified as the main product according to XRD and SEM-XEDS observations. In addition, the elimination of lime and Ca(OH)2 in the BOF slag during carbonation is beneficial to its further use as construction material. Consequently, the developed RPB process could capture the CO2 from the flue gas, neutralize the CRW, and demonstrate the utilization potential for BOF slag. It was also concluded that carbonation of BOF slag coupled with CRW in an RPB is a viable method for CO2 capture due to its higher mass transfer rate and CO2 removal efficiency in a short reaction time.
具有强碱性的转炉渣和冷轧废水在利用和/或最终处置前都需要进行稳定化和中和处理。利用烟道气中的 CO2 作为稳定化和中和剂，还可以减少 CO2 的排放。在这项研究中，在转鼓式填充床中，通过转炉渣与冷轧废水的加速碳酸化反应原位捕获了炼钢过程中含有 30 体积%CO2 的热炉气。所开发的转鼓式填充床工艺表现出优异的结果，在 25°C 和 1 大气压下，仅需 1 分钟的短反应时间，即可实现高达 96-99%的烟气 CO2 去除效率（η）。根据 XRD 和 SEM-XEDS 的观察，确定主要产物为方解石（CaCO3）。此外，碳酸化过程中去除转炉渣中的石灰和 Ca(OH)2 有利于其进一步用作建筑材料。因此，所开发的转鼓式填充床工艺可以从烟道气中捕获 CO2，中和冷轧废水，并展示了转炉渣的利用潜力。研究还得出结论，由于在短反应时间内具有更高的传质速率和 CO2 去除效率，因此在转鼓式填充床中通过转炉渣与冷轧废水的碳酸化反应来捕获 CO2 是一种可行的方法。
