Inexpensive High Sensitivity CO2 Isotopologue Sensor

Next generation advances in subsurface technologies will enable access to large amounts of clean, renewable geothermal energy, as well as safer development of domestic natural gas supplies. The subsurface also provides hundreds of years of safe storage capacity for carbon dioxide (CO2) and opportunities for environmentally responsible management and disposal of hazardous materials and other energy waste streams. Subsurface storage requires mastery of a number of critical technologies including safely and cost efficiently accessing the subsurface, maintaining optimal conditions for storage over time, and monitoring the subsurface. In this program, Amethyst Research proposes to develop and deliver a rugged, compact, low power, low cost, ultra high sensitivity subsurface CO2 measurement system that can differentiate between 13CO2 and 12CO2 isotopologues. The CO2 monitoring sensor will be small and low cost so multiple sensors can be placed throughout the subsurface area to be monitored. The individual CO2 sensors will be based on a novel infrared resonant cavity detector that can be tuned to detect only selected wavelengths. A simple LED based infrared light source can then be used with detector to measure the CO2 with high accuracy and sensitivity. The detectors can be tuned to independently detect the CO2 isotopologues. This information can then be sent to a base station for concentration analysis and recording. In the Phase I program Amethyst Research will develop and optimize the resonant cavity infrared detector optimized to detect light in and around 4.35 m where the 12CO2 and 13CO2 absorption bands are strong and well separated. The Phase I program will also design the entire CO2 sensing system. Amethyst Research is developing an ultra sensitive gas detection system that will be able to accurately and rapidly monitor subsurface green house gases such as CO2 and determine whether these gases are natural and/or anthropogenic in origin. Commercial Application and Other Benefits: Amethyst is developing a low noise high sensitivity mid infrared resonant cavity detector for use in CO2 monitoring. This technology can be translated to other applications including monitoring of other gases as well as IR imagining and IR tomography.