煤气化渣二氧化碳矿化隔离实验研究

冯一帆; 张旭光; 熊卓; 赵永椿; 张军营

doi:10.13226/j.issn.1006-6772.24100702

煤气化渣二氧化碳矿化隔离实验研究

Experimental study on carbon dioxide mineralization and sequestration of coal gasification slag

摘要

摘要: CO2矿化作为一种CO2永久固定技术备受关注。而煤气化渣作为一种存量巨大的碱性固废在CO2矿化方面的研究较少。本文选取新疆淖毛湖地区煤气化渣为原料，采用直接液相的方法进行煤气化渣二氧化碳矿化隔离实验，探讨了反应温度、初始压力、液固比、反应时间和反应气氛对矿化效率和CO2吸收率的影响，确定煤气化渣最佳矿化反应参数，揭示煤气化渣直接液相矿化反应机理。研究结果表明，煤气化渣原样中富含Ca2+、Na+、Fe3+等碱金属元素，其中CaO的质量分数高达18.89%，主要以石灰石（CaCO3）和钙黄长石（Ca2Al2SiO7）的形式存在。提高反应温度能够显著提高煤气化渣矿化效率和CO2吸收率，且提升速率逐渐减缓。加压可以提高矿化效率，但会降低CO2吸收率。在300℃、5 MPa的条件下矿化效率达到89.05%，CO2固定量为75.86 kg CO2/t CGS。矿化效率随着液固比的增大呈现先升高后降低的趋势，在10 L/Kg的条件下达到峰值。模拟纯CO2条件下的矿化效率在三种反应气氛中最高，而模拟空气燃烧烟气条件下的CO2吸收率高于其他气体，达到76.39%。综合考虑，确定煤气化渣CO2矿化系统的最佳反应条件为反应温度300℃、初始压力3 MPa、液固比10 L/kg、反应时间40min。揭示了煤气化渣CO2矿化过程气固液三相反应机理，实质上是钙黄长石与二氧化碳生成碳酸钙的反应，明确H+与钙黄长石反应浸出Ca2+是碳酸化反应的主控步骤。

Abstract: CO2 mineralization has attracted significant attention as a permanent carbon sequestration technology. However, research on the use of coal gasification slag(CGS), a large-scale alkaline solid waste, for CO? mineralization is limited. This study selects coal gasification slag from the Naomaohu area in Xinjiang as the raw material and conducts experiments on CO? sequestration and mineralization using a direct aqueous phase method. The effects of reaction temperature, initial pressure, liquid-solid ratio, reaction time, and reaction atmosphere on mineralization efficiency and CO? absorption rate are explored. The optimal mineralization conditions for coal gasification slag are determined, and the mechanism of direct aqueous mineralization of coal gasification slag is elucidated. The results show that the gasification slag is rich in alkaline elements such as Ca2+, Na+, and Fe3+, with CaO content?of?up?to 18.89%, primarily in the form of limestone (CaCO3) and gehlenite (Ca2Al2SiO7). Increasing reaction temperature significantly improves mineralization efficiency and CO2 absorption rate,

HTML全文

参考文献(0)

施引文献

资源附件(0)