In Situ Optical Monitor for Waste Tank Gases

Department of Energy waste storage tanks require continuous monitoring of species in solid, liquid and gaseous phases. Gas phase species of interest include ammonia, methane, carbon dioxide and hydrogen. This project will develop in situ optical sensors that selectively and sensitively detect ammonia, methane, carbon dioxide, hydrogen and oxygen in the waste tank headspace. The sensors will take advantage of a rugged, compact, optical absorption method and inexpensive near-infrared lasers. In Phase I, an optical spectrometer for the detection of ammonia, methane, carbon dioxide, hydrogen, and oxygen was constructed, based on a single common sample cell. The sensitivity of the spectrometer for each species was quantified. In Phase II, fully-integrated sensor prototypes, based on laser-diode photoacoustic spectroscopy, will be constructed for waste tank headspace analysis, and standard operating protocols for the sensors will be established. The prototypes will be refined through beta-testing in several field applications, which are also Phase III commercialization opportunities. Commercial Applications and other Benefits as described by the awardee: The new spectrometer, which would offer high-performance in a rugged compact package, could be manufactured inexpensively relative to existing devices of comparable performance. The instrument would offer a compelling blend of price, performance, and physical advantages in a variety of gas detection applications. Applications include atmospheric monitoring, environmental regulatory compliance, process gas analysis, and biomedical breath diagnostics.