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Diesel particulate filters (DPFs) are essential particulate matter emission control devices. Some diesel particulate filters have been observed to fail during industrial-fleet vehicle use. DPFs that fail during vehicle use compromise particulate matter emission capture. Herein, failures in cordierite DPF substrates observed during commercial fleet use were characterized as pinhole failure, melt failure, crack failure, and fouling failure. The observed failures were correlated to particulate matter chemical composition and physical changes in the cordierite substrate of the exhausted DPFs. The physical-chemical characteristics of pinhole failure, melt failure, crack failure, and fouling failure were determined by applying scanning electron microscopy-energy dispersive spectrometry (SEM-EDS), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). Results indicate that the chemical composition and crystalline structures of cordierite DPF substrate changed according to the failure characterization. The specific changes to the cordierite substrate during failure can contribute towards understanding fundamental DPF failure mechanisms.

An alternative fuel to replace foundry coke in cupolas was developed from waste anthracite fines. Waste anthracite fines were briquetted with Si-containing materials and treated in carbothermal (combination of heat and carbon) conditions that simulated the cupola preheat zone to form silicon carbide nanowires (SCNWs). SCNWs can provide hot crushing strengths, which are important in cupola operations. Lab-scale experiments confirmed that the redox level of the Si-source significantly affected the formation of SiC. With zerovalent silicon, SCNWs were formed within the anthracite pellets. Although amorphous Si (+4) plus anthracite formed SiC, these conditions did not transform the SiC into nanowires. Moreover, under the test conditions, SiC was not formed between crystallized Si (+4) and anthracite. In a full-scale demonstration, bricks made from anthracite fines and zerovalent silicon successfully replaced a part of the foundry coke in a full-scale cupola. In addition to saving in fuel cost, replacing coke by waste anthracite fines can reduce energy consumption and CO2 and other pollution associated with conventional coking.

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