In-Situ FT-IR Monitoring of a Solar Flux Induced Chemical Process

Abstract

The capability to perform in-situ, on-line monitoring of processes induced by concentrated solar flux will enhance the development and utilization of solar technologies. Temperature measurements and chemical concentration measurements provide an understanding of the ongoing chemistry, process limits, and process reproducibility. A Fourier transform infrared (FT-IR) spectrometer was optically coupled to a quartz flow reactor at the High Flux Solar Furnace of the National Renewable Energy Laboratory in Golden, CO. In-situ emission/transmission spectroscopy was utilized to simultaneously monitor steam temperature and the concentration of formed hydrogen bromide during the solar flux induced reaction of steam and bromine. The photochemical process is being investigated for the production of industrial quantities of hydrogen and oxygen, where downstream electrolysis of the formed hydrogen bromide provides the hydrogen and regenerates bromine. Steam temperature was measured to increase upon the addition of bromine to the reactor. Gas temperature increases of 200°C to 400°C were observed. Hydrogen bromide concentrations up to ten percent of the reactor gas volume were measured. The FT-IR system provided quantitative information of two critical parameters of the measured process and serves to accelerate this technology area.