The slow combustion of cyclo pentane - II. Analytical results and mechanism

Source abstract

Abstract The products of the oxidation of cyclopentane in the gas phase at around 400 °C in an uncoated vessel were water, carbon monoxide and carbon dioxide with smaller amounts of hydrogen, methane, ethylene, propylene, cyclopentane, formaldehyde, higher aldehydes (mainly acetaldehyde) and acids. It was confirmed that the pressure change was true measure of the extent of reaction. The pressures of higher aldehydes and unsaturates rose to a maximum at about the time of the maximum rate, and the variation of these maximum pressures with initial oxygen and cyclopentane pressures was investigated. Addition of formaldehyde initially had little effect on the reaction, but addition of higher aldehydes reduced the induction period and increased the maximum rate. The CO/CO2ratio increased with increasing temperature and cyclopentane pressure and was much greater with the boric-acid-coated vessel. Also using this vessel peroxidic material was detected in the products. Higher aldehydes were probably the substances responsible for delayed branching. The various elementary reactions which may have occurred in the system are discussed and a reaction scheme which can explain the products and to some extent the kinetic results is proposed. Cyclopentylperoxy (C5H9O2) radicals were probably important both in propagating and terminating the chains.