An experimental study of ash behaviour and the potential fate of ZnO/Zn in the Co-combustion of pulverised South African coal and waste tyre rubber
An experimental study of ash behaviour and the potential fate of ZnO/Zn in the Co-combustion of pulverised South African coal and waste tyre rubber
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DOI：
10.1016/j.fuel.2013.04.026
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发表时间：
2013-09
期刊：
影响因子：
7.4
通讯作者：
Surjit Singh;W. Nimmo;Paul T. Williams
中科院分区：
文献类型：
--
作者：
Surjit Singh;W. Nimmo;Paul T. Williams
提出了一种利用废轮胎橡胶（WTR）作为二次燃料在煤粉电厂中的新型燃烧应用。在80 kWthcombustion test facility（CTF）中进行了南非煤（SAf）与WTR在燃料分数（FF）为4.1%、14.1%和19.7%沿着的纯燃烧WTR的共燃烧。这项研究评估了潜在的结渣和污垢的行为所产生的灰烬共烧SAF/WTR和纯烧WTR。共烧SAf/WTR和纯烧WTR灰的XRF和ICP/OES分析显示酸性氧化物的高组成。基于熔融性指数（B/A、RS、SR、F和Fu），确定共烧SAf/WTR和纯烧WTR灰具有低的结渣和结垢风险。氧化锌（ZnO）作为复合添加剂被用于轮胎制造。ZnO存在于未加工的WTR中，提出了燃烧过程中其命运的问题。在这项研究中，从纯烧WTR和共烧SAF/WTR收集和分析的灰分显示出比预期更低的锌水平。研究表明，在温度>1200 °C时，ZnO在CTF内保持气相状态。实验分析发现，在较低温度下，在旋风捕集器收集的飞灰或从CTF的水冷却部分收集的灰沉积物中，Zn富集并不显著。这表明锌可能形成亚微米气溶胶。还应注意，由于ZnO/Zn的挥发性，其不太可能在结渣/结垢机制中有显著贡献。然而，本研究强调了在任何工业应用之前需要对共烧SAf/WTR进行进一步的实验评估。
A novel combustion application utilising waste tyre rubber (WTR) as a secondary fuel in pulverised coal power plants is presented. Co-combustion of a South African coal (SAf) with WTR at the fuel fractions (FFs) 4.1%, 14.1%, and 19.7% along with the pure firing of WTR was conducted in an 80 kWthcombustion test facility (CTF). This study assessed the potential slagging and fouling behaviour of the resultant ashes produced from co-firing SAf/WTR and pure fired WTR. XRF and ICP/OES analysis of the co-fired SAf/WTR and pure fired WTR ashes revealed a high composition of acidic oxides. Based on the fusibility indices (B/A,RS,SR,F, andFu) it was determined that co-fired SAf/WTR and pure fired WTR ashes carry a low risk of slagging and fouling. Zinc oxide (ZnO) is incorporated in the manufacturing of tyres as a compounding additive. ZnO is present within raw WTR, posing the question as to its fate during combustion. In this study ash collected and analysed from the pure fired WTR and co-fired SAf/WTR exhibited lower levels of Zn than anticipated. It is suggested that ZnO remains in the vapour phase within the CTF at temperatures >1200 °C. Experimental analysis found Zn enrichment at lower temperatures was not significant within the fly ash collected by the cyclone trap or ash deposits collected from the water cooled sections of the CTF. This suggests that Zn could be forming a submicron aerosol. It is further noted that ZnO/Zn is not likely to contribute significantly in the slagging/fouling mechanisms, due to its volatile nature. However this present study highlights the need for further experimental assessment of co-firing SAf/WTR required prior to any industrial application.