碳捕捉对电石渣-钢渣复合相变储热材料性能的影响

Effects of CO_(2) capture on carbide-steel slag shape-stable phase-change composites

为资源化利用工业固废,降低储热系统成本,选取电石渣和钢渣1∶1混合进行CO_(2)捕集和封存,将封存CO_(2)的电石渣-钢渣混合材料作为骨架材料制备7种不同配比的NaNO_(3)/固碳电石渣-钢渣复合相变储热材料。通过热重分析法探究电石渣-钢渣混合材料的固碳性能,利用差示扫描量热法、高温热冲击法、X射线衍射法、电子显微法表征其储热性能、热循环稳定性、化学相容性和微观结构。结果表明,电石渣-钢渣混合材料的固碳率为24.48%;最佳热性能样品CC-SC4中NaNO_(3)、电石渣和钢渣的质量比为2∶1∶1,100~400℃工作温度内储热密度达到444.2 J/g,热导率为1.057 W/(m·K),各组分间具有良好的化学相容性;样品CC-SC4经历1440次加热/冷却循环后仍具有优异的储热性能。

To achieve sufficient utilization of industrial solid waste and reduce the cost of thermal energy storage(TES) systems,a mixture of alkaline solid waste of carbide slag(CS)and steel slag(SS) is selected at a 1∶1 ratio for CO_(2) capture and sequestration.In addition,seven types of carbon-captured shape-stable phase-change composite materials(CCSMs)with different ratios of NaNO_(3)/CS-SS were prepared by combining CS and SS as the skeleton materials after CO_(2) sequestration.Furthermore,thermogravimetric analysis was conducted to characterize the carbon sequestration properties of the CS-SS hybrid materials.Moreover,the TES performance,thermal cycling stability,chemical compatibility,and microstructure of CCS were characterized using differential scanning calorimetry(DSC),high-temperature thermal shock method,X-ray diffraction(XRD) analysis,and scanning electron microscopy.The results indicate that the carbon-sequestration rate of the CS-SS hybrid material is 24.48%.Furthermore,the mass ratio of NaNO_(3),CS,and SS in the best thermal performance sample of CC-SC4 was 2∶ 1∶ 1,with its thermal storage density reaching 444.2 J/g at a working temperature of 100—400 ℃,thermal conductivity of 1.057 W/(m·K),and chemical compatibility among the components.Sample CC-SC4 exhibited excellent thermal storage performance after 1440 heating/cooling cycles.