School of Environment, Tsinghua University, 100084 Beijing (PR China), Fax: (+86) 10-62783548.
ChemSusChem. 2013 Dec;6(12):2348-55. doi: 10.1002/cssc.201300436. Epub 2013 Aug 2.
Direct gas-solid carbonation of steel slag under various operational conditions was investigated to determine the sequestration of the flue gas CO2 . X-ray diffraction analysis of steel slag revealed the existence of portlandite, which provided a maximum theoretical CO2 sequestration potential of 159.4 kg CO 2 tslag (-1) as calculated by the reference intensity ratio method. The carbonation reaction occurred through a fast kinetically controlled stage with an activation energy of 21.29 kJ mol(-1) , followed by 10(3) orders of magnitude slower diffusion-controlled stage with an activation energy of 49.54 kJ mol(-1) , which could be represented by a first-order reaction kinetic equation and the Ginstling equation, respectively. Temperature, CO2 concentration, and the presence of SO2 impacted on the carbonation conversion of steel slag through their direct and definite influence on the rate constants. Temperature was the most important factor influencing the direct gas-solid carbonation of steel slag in terms of both the carbonation conversion and reaction rate. CO2 concentration had a definite influence on the carbonation rate during the kinetically controlled stage, and the presence of SO2 at typical flue gas concentrations enhanced the direct gas-solid carbonation of steel slag. Carbonation conversions between 49.5 % and 55.5 % were achieved in a typical flue gas at 600 °C, with the maximum CO2 sequestration amount generating 88.5 kg CO 2 tslag (-1) . Direct gas-solid carbonation of steel slag showed a rapid CO2 sequestration rate, high CO2 sequestration amounts, low raw-material costs, and a large potential for waste heat utilization, which is promising for in situ carbon capture and sequestration in the steel industry.
在各种操作条件下对钢渣的直接气固碳化进行了研究，以确定烟道气 CO2 的固存。钢渣的 X 射线衍射分析表明存在氢氧化钙，根据参考强度比法计算，其最大理论 CO2 固存潜力为 159.4 kg CO2 tslag(-1)。碳化反应通过快速动力学控制阶段进行，其活化能为 21.29 kJ mol(-1)，随后是 10(3)数量级较慢的扩散控制阶段，其活化能为 49.54 kJ mol(-1)，分别可以用一级反应动力学方程和金斯廷方程来表示。温度、CO2 浓度和 SO2 的存在通过直接和明确地影响速率常数来影响钢渣的碳化转化率。在钢渣的直接气固碳化方面，温度是最重要的因素，无论是碳化转化率还是反应速率都是如此。CO2 浓度在动力学控制阶段对碳化速率有一定的影响，而在典型烟道气浓度下存在 SO2 会增强钢渣的直接气固碳化。在 600°C 的典型烟道气中，碳化转化率在 49.5%至 55.5%之间，最大 CO2 固存量为 88.5 kg CO2 tslag(-1)。钢渣的直接气固碳化具有快速的 CO2 固存速率、高的 CO2 固存量、低廉的原材料成本和大量利用余热的潜力，这对于钢铁行业的原位碳捕获和封存具有广阔的前景。
