APPARATUS FOR SHORT-TIME MEASUREMENTS IN A FIXED-BED GAS SOLID REACTOR

An apparatus for exposure of a solid to reactive process gas is described which makes possible short time (≥0.3 to 15 s) exposures in a fixed-bed reactor. Operating conditions for differential reaction with respect to the gas concentration and rapid quench for arresting high-temperature reactions are made possible by high gas flowrates through the sample bed. The residence time of solid exposure to the reactive gases is timed by a photosensor emitter/detector and oscilloscope. For times under 2 s, the standard deviation of the residence times is less than 10 ms. The ease of apparatus construction and operation, the operable temperature range (ambient to 850°C), and the reproducibility of residence times down to 0.3 s makes the apparatus ideal for kinetic studies of rapid gas/solid reactions.