Simulations of a Micro-Reactor for the Study of the Unimolecular Decomposition of Large Fuel Molecules

It is now possible to use heated micro-reactors to carry out flash pyrolysis of complex fuels. These reactors involve small (1 mm ID, 2-3 cm long) flow reactors equipped with advanced diagnostics. Based on the well known “Chen Nozzle” the residence time in the reactor is very short, 25-150 microseconds, allowing study of the earliest kinetic processes. The diagnostics, matrix isolation/infrared spectroscopy (IR) and photoionization mass spectroscopy (PIMS), in combination allow us to identify all species present. This includes atoms, radicals and metastables as well as stable species. However, a major disadvantage of the system is a lack of understanding of the internal fluid dynamics. Without detailed knowledge of the velocity, temperature and density distributions within the reactor, it is not possible to extract reliable kinetic information. In this paper we report the results of reacting CFD simulations of the flow within and downstream of the reactor.