Thermal conversion of coal-tar pitch in the presence of silicon compounds

• Published in: Solid fuel chemistry Vol. 44; no. 1; pp. 5 - 11
• Main Authors: Efimova, O. S., Khokhlova, G. P., Patrakov, Yu. F.
• Format: Journal Article
• Language: English
• Published: Heidelberg Allerton Press, Inc 01.02.2010
• Subjects: Chemistry; Chemistry and Materials Science; Physical Chemistry; Thermal Degradation; Solid Fuel Chemistry; Solid Residue; Thermal Conversion; Carbon Material
• ISSN: 0361-5219; 1934-8029
• DOI: 10.3103/S0361521910010027

The effect of SiO 2 and polycarbosilane (PCS) additives on the thermal degradation of coal-tar pitch at temperatures to 900°C was studied by thermogravimetric analysis, differential thermal analysis, mass-spectrometric analysis, IR spectroscopy, and electron microscopy. It was found that, in the presence of the test additives, the character of release and the quantitative composition of volatile degradation products changed, the degree of aromaticity of the carbon residue decreased, and the concentration of oxygen-containing groups in this residue increased. In the case of the PCS additive, the combined thermal conversion of both of the components occurred. In this case, the contribution of structurization processes increased to cause a nonadditive increase in the yield of solid residue. Silicon mainly occurred as organosilicon fragments with Si-C and Si-O-C bonds, an oxycarbide, and, probably, silicon carbide. In the case of the SiO 2 additive, oxidation processes were enhanced; the yield of carbon somewhat decreased, and siloxane groups were present in the solid residue.