Comparative investigation on tetramethylsilane and neopentane combustion: Jet-stirred reactor pyrolysis and kinetic modeling

Abstract

This work reports a comparative study on jet-stirred reactor (JSR) pyrolysis of tetramethylsilane (TMS) and neopentane at 1.04 bar and 770–1070 K. Gas chromatography (GC) was used to detect pyrolysis products and measure their mole fraction profiles versus heating temperature. TMS was observed to decompose about 70 K later than neopentane, showing a slower reactivity than its hydrocarbon counterpart. Hydrocarbon products such as methane, ethylene, ethane and propene were detected in the TMS pyrolysis, while besides TMS, no other Si-containing species was observed. Methane, acetylene, ethylene and isobutene were observed as dominant products in the neopentane pyrolysis. The pyrolysis models of TMS and neopentane were developed and validated against the present data, as well as the previous pyrolysis data of TMS. The available rate constants of SiC bond dissociation reaction were evaluated based on the mole fraction profiles of TMS in the present and previous pyrolysis work over a wide temperature region. The influence of methane-elimination reactions on the decomposition of TMS and neopentane was also discussed. Rate of production (ROP) analysis and sensitivity analysis were performed to provide insight into the fuel decomposition chemistry in both the TMS and neopentane pyrolysis. The SiC/CC bond dissociation reactions and methane-elimination reactions were concluded to be the crucial fuel consumption pathways in both the TMS and neopentane pyrolysis.