Assi Ahmad, Federici Stefania, Bilo Fabjola, Zacco Annalisa, Depero Laura E, Bontempi Elza
INSTM and Chemistry for Technologies Laboratory, Department of Mechanical and Industrial Engineering, University of Brescia, Via Branze, 38, 25123 Brescia, Italy.
Materials (Basel). 2019 Aug 24;12(17):2714. doi: 10.3390/ma12172714.
Mineral carbonation, involving reactions of alkaline earth oxides with CO has received great attention, as a potential carbon dioxide sequestration technology. Indeed, once converted into mineral carbonate, CO can be permanently stored in an inert phase. Several studies have been focalized to the utilization of industrial waste as a feedstock and the reuse of some by-products as possible materials for the carbonation reactions. In this work municipal solid waste incineration fly ash and other ashes, as bottom ash, coal fly ash, flue gas desulphurization residues, and silica fume, are stabilized by low-cost technologies. In this context, the CO is used as a raw material to favor the chemical stabilization of the wastes, by taking advantage of the pH reduction. Four different stabilization treatments at room temperature are performed and the carbonation reaction evaluated for three months. The crystalline calcium carbonate phase was quantified by the Rietveld analysis of X-ray diffraction (XRD) patterns. Results highlight that the proposed stabilization strategy promotes CO sequestration, with the formation of different calcium carbonate phases, depending on the wastes. This new sustainable and promising technology can be an alternative to more onerous mineral carbonation processes for the carbon dioxide sequestration.
矿物碳酸化，即碱土金属氧化物与二氧化碳的反应，作为一种潜在的二氧化碳封存技术受到了广泛关注。事实上，一旦转化为矿物碳酸盐，二氧化碳就可以永久储存在惰性相中。多项研究聚焦于将工业废弃物用作原料以及将一些副产品再利用作为碳酸化反应的可能材料。在这项工作中，城市固体废弃物焚烧飞灰和其他灰烬，如底灰、煤飞灰、烟气脱硫残渣和硅灰石，通过低成本技术进行稳定化处理。在此背景下，利用二氧化碳作为原料，通过降低pH值来促进废弃物的化学稳定化。在室温下进行了四种不同的稳定化处理，并对碳酸化反应进行了为期三个月的评估。通过对X射线衍射（XRD）图谱的Rietveld分析对结晶碳酸钙相进行了定量。结果表明，所提出的稳定化策略促进了二氧化碳的封存，根据废弃物的不同形成了不同的碳酸钙相。这种新的可持续且有前景的技术可以替代更为繁琐的矿物碳酸化过程用于二氧化碳封存。
