Dpto. Ingeniería Energética, Escuela Técnica Superior de Ingenieros, Universidad de Sevilla, Sevilla, Spain.
Dpto. Física de la Materia Condensada, Instituto de Ciencia de Materiales de Sevilla, Universidad de Sevilla, Consejo Superior de Investigaciones Científicas, Sevilla, Spain.
J Environ Manage. 2017 Dec 1;203(Pt 3):907-919. doi: 10.1016/j.jenvman.2017.05.003. Epub 2017 May 9.
Biomorphic Silicon Carbide (bioSiC) is a novel porous ceramic material with excellent mechanical and thermal properties. Previous studies have demonstrated that it may be a good candidate for its use as particle filter media of exhaust gases at medium or high temperature. In order to determine the filtration efficiency of biomorphic Silicon Carbide, and its adequacy as substrate for diesel particulate filters, different bioSiC-samples have been tested in the flue gases of a diesel boiler. For this purpose, an experimental facility to extract a fraction of the boiler exhaust flow and filter it under controlled conditions has been designed and built. Several filter samples with different microstructures, obtained from different precursors, have been tested in this bench. The experimental campaign was focused on the measurement of the number and size of particles before and after placing the samples. Results show that the initial efficiency of filters made from natural precursors is severely determined by the cutting direction and associated microstructure. In biomorphic Silicon Carbide derived from radially cut wood, the initial efficiency of the filter is higher than 95%. Nevertheless, when the cut of the wood is axial, the efficiency depends on the pore size and the permeability, reaching in some cases values in the range 70-90%. In this case, the presence of macropores in some of the samples reduces their efficiency as particle traps. In continuous operation, the accumulation of particles within the porous media leads to the formation of a soot cake, which improves the efficiency except in the case when extra-large pores exist. For all the samples, after a few operation cycles, capture efficiency was higher than 95%. These experimental results show the potential for developing filters for diesel boilers based on biomorphic Silicon Carbide.
生物形态碳化硅（bioSiC）是一种具有优异机械和热性能的新型多孔陶瓷材料。先前的研究表明，它可能是作为中高温废气颗粒过滤器介质的候选材料之一。为了确定生物形态碳化硅的过滤效率及其作为柴油颗粒过滤器基板的充分性，不同的生物形态碳化硅样品已在柴油锅炉的烟道气中进行了测试。为此，设计并建造了一个实验设备，以提取锅炉排气流的一部分，并在受控条件下对其进行过滤。已经在该台架上测试了几种具有不同微观结构的不同生物形态碳化硅样品，这些样品是由不同的前体制得的。实验活动的重点是测量样品放置前后颗粒的数量和大小。结果表明，由天然前体制得的过滤器的初始效率受到切割方向和相关微观结构的严重影响。在从径向切割木材中得到的生物形态碳化硅中，过滤器的初始效率高于 95%。然而，当木材的切割为轴向时，效率取决于孔径和渗透率，在某些情况下达到 70-90%的范围内。在这种情况下，一些样品中的大孔会降低其作为颗粒捕集器的效率。在连续运行过程中，多孔介质内颗粒的积累会导致积碳层的形成，从而提高效率，但在存在特大孔的情况下除外。对于所有样品，在几个操作循环后，捕获效率高于 95%。这些实验结果表明，基于生物形态碳化硅开发柴油锅炉过滤器具有潜力。
