A novel CVD/CVI reactor with an in-situ sampling apparatus connected to an online GC/MS

Spatially resolved analysis of the composition of the gas-phase during chemical vapor deposition depends on an effective sampling apparatus. In the present work, a novel in-situ sampling and cooling apparatus was presented, which is connected directly to an online GC/MS. Simulations of the temperature distribution in the cooling apparatus show that sample gas can be cooled down to 600 K in short time, resulting in a gas-phase composition quench. This device was employed to analyze gas-phase composition resulting from the pyrolysis of methane. Experiments were carried out at an oven temperature of 1150 °C to investigate the composition along the axis of a tubular reactor. Flow fields of the tubular reactor were predicted numerically neglecting volume changes due to chemical reactions involved in methane decomposition.