EMPI - Reactive Fluids

The flow reactor enables the extension of experiments of unimolecular decomposition reactions to lower temperatures with reaction times up to a factor of 1000 longer compared to the shock-tube studies. The flow reactor also enables studies of heterogeneous reactions.
The flow reactor consists of a 250 cm long quartz tube with an internal diameter of 26 mm placed in two tube furnaces, heated up to 1200 °C with resistance heating elements. The 90-cm long gas pre-heater and the 120-cm long reactor oven are connected by a thermally insulated, 5-cm long unheated connection. The gas preheater is usually kept 150 K below the temperature of the reactor to homogeneously pre-heat the gas to a temperature low enough to not initiate reactions, ensuring fast subsequent heat-up to the test temperature in the reactor. Gases are supplied by mass flow controllers. Liquid reactants are evaporated in a stainless steel bubbler. The initial reactant concentration is regulated by the flow of bath gas through the bubbler. At the outlet of the flow reactor, a gas sampling unit with ten different probe units is attached. The gas samples are analyzed with a GC/MS system via an autosampler.
For measuring heterogeneous rate coefficients that are important for particle synthesis, a separate oven is connected in front of the flow reactor. In this oven, the particle precursor are introduced with mass flow controllers and form particles which are mixed in flow reactor with a reactant. The rate coefficient is then determined by the consumption of this reactant measured by GC/MS. The particles are characterized with a scanning mobility particle analyzer (SMPS), a quartz crystal microbalance, or by transmission electron microscopy.