Carbon material formation on SBA-15 and Ni-SBA-15 and residue constituents during acetylene decomposition

• Published in: Journal of hazardous materials 2014-07, Vol.276, p.43-51
• Main Authors: Chiang, Hung-Lung, Wu, Trong-Neng, Ho, Yung-Shou, Zeng, Li-Xuan
• Format: Article
• Language: English
• Subjects: Acetylene; Acetylene - chemistry; Adsorption; Applied sciences; Atmospheric pollution; Carbon; Carbon - chemistry; Carbon materials; Chemical vapor deposition (CVD); Constituents; Decomposition; Exact sciences and technology; Microscopy, Electron, Scanning; Nickel; Nitrogen - chemistry; Pollution; Polycyclic aromatic hydrocarbon (PAH); Polycyclic Aromatic Hydrocarbons - analysis; Residues; Silicon Dioxide - chemistry; Spectroscopy; Spectrum Analysis, Raman; Volatile organic compound (VOC); Volatile organic compounds; Volatile Organic Compounds - analysis; Volatile Organic Compounds - classification
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2014.05.016

•Acetylene was decomposed on SBA-15 and Ni-SBA-15 at 650–850°C.•Carbon spheres and filaments were formed after acetylene decomposition.•PAHs were determined in tar and residues.•Exhaust constituents include CO2, H2, NOx and hydrocarbon species. Carbon materials including carbon spheres and nanotubes were formed from acetylene decomposition on hydrogen-reduced SBA-15 and Ni-SBA-15 at 650–850°C. The physicochemical characteristics of SBA-15, Ni-SBA-15 and carbon materials were analyzed by field emission scanning electronic microscopy (FE-SEM), Raman spectrometry, and energy dispersive spectrometry (EDS). In addition, the contents of polyaromatic hydrocarbons (PAHs) in the tar and residue and volatile organic compounds (VOCs) in the exhaust were determined during acetylene decomposition on SBA-15 and Ni-SBA-15. Spherical carbon materials were observed on SBA-15 during acetylene decomposition at 750 and 850°C. Carbon filaments and ball spheres were formed on Ni-SBA-15 at 650–850°C. Raman spectroscopy revealed peaks at 1290 (D-band, disorder mode, amorphous carbon) and 1590 (G-band, graphite sp2 structure)cm−1. Naphthalene (2 rings), pyrene (4 rings), phenanthrene (3 rings), and fluoranthene (4 rings) were major PAHs in tar and residues. Exhaust constituents of hydrocarbon (as propane), H2, and C2H2 were 3.9–2.6/2.7–1.5, 1.4–2.8/2.6–4.3, 4.2–2.4/3.2–1.7% when acetylene was decomposed on SBA-15/Ni-SBA-15, respectively, corresponding to temperatures ranging from 650 to 850°C. The concentrations of 52 VOCs ranged from 9359 to 5658 and 2488 to 1104ppm for SBA-15 and Ni-SBA-15 respectively, at acetylene decomposition temperatures from 650 to 850°C, and the aromatics contributed more than 87% fraction of VOC concentrations.