Kinetics of copyrolysis of coal with polyamide 6

Kinetics of thermal reactions of coal with polyamide 6 by TGA and DSC methods was studied and overall kinetic parameters were measured. In the range of about 350-500 degreesC the thermal degradation of coal proceeds, and gas and tar are evolved. Simultaneously, the thermal decomposition of polyamide 6 occurs and E-caprolactam and other products are formed. The E-caprolactam formation is promoted by water and hydrogen from coal degradation. Due to high content of hydrogen, coal acts as a strong H-donor. Because polyamide 6 is a significant component of waste polyamides mixtures and waste plastics, the thermal treatment of waste polyamides with coal was tested during copyrolysis in a stationary bed up to final temperature of 900 degreesC at the heating rate of 5 degreesC min(-1). It was found that beside E-caprolactam mainly carbon oxides, methane, aliphatic hydrocarbons, simple aromatics and stable oil are formed during copyrolysis. The yields of gas and tar/oil from copyrolysis with polyamides are higher in comparison with those from pyrolysis of coal alone. (C) 2003 Elsevier B.V. All rights reserved.