University of Pittsburgh and US Department of Energy scientists have developed a gas sensor, capable of identifying and characterizing various gases in real time. A wide range of applications is possible, including improved efficiency in the petrochemical industry.
Description
The use of fiber optics in sensor applications provides a variety of benefits and can be utilized within harsh environments where electronic sensors are unable to perform. Estimate that the fiber optic sensor market will reach$2.39 billion by 2025, this is mainly due to their ability to be utilized in industry sectors such as oil & gas, infrastructure, civil engineering, and power & utility. The innovations detail the use of Fiber Bragg grating, Rayleigh backscattering, Brillouin backscattering, Raman backscattering, and other methods of increasing the efficacy of fiber optics. Dr. Chen’s research employs distributed fiber-sensing schemes to fiber optics for detecting both physical parameters (i.e. radiation, temperature, strain, pressure) and chemical information (i.e. hydrogen concentration). Other techniques proposed include altering the refractive index of certain metal oxides and the integration of fiber optic sensors seamlessly within already existing electrical cable networks.
Applications
• Petrochemical industry
• Pollutant monitoring
• Monitoring of gases for medical (e.g., in anesthesia) and safety (e.g., mining or defense) purposes
Advantages
Current approaches, mass spectrometry and gas chromatography, traditionally used to detect and analyze gases are costly in terms of resources and time. Previous efforts to use Raman spectroscopy have failed due to detection issues. Real-time gas analysis could have many uses, including characterizing natural gases in a pipeline and improving efficiency of gas-fired turbine electricity generators through adjustment of parameters. It would require rapid information, at least every second and with a high degree of accuracy – something no current commercial gas sensor can achieve.
This new gas sensor would allow for fast, accurate analysis of many gases at once including methane, carbon monoxide, butane and ammonia. The gas sensor will excite samples using a laser and collect spontaneous optical Raman emissions. The design of the sensor, incorporating a new type of hollow optical waveguide to collect both gases and Raman photons, allows for a more efficient use of Raman scattering and leads to faster and more accurate Raman analysis than previously achievable. This faster, lower cost detection method could expand the use of gas detection to a variety of areas such as real-time analysis for defense or homeland security purposes and the monitoring of gases during anesthesia.
Invention Readiness
A prototype gas sampler has been produced using various waveguides, lasers, detectors, and optics. Testing has established sensing time and detectable limits for a variety of gases. Further optimization is required to develop a design using a waveguide to collect gases and detect Raman scattering, and spatial filtering to remove noise could improve signal collection efficiency by as much as 1000 times compared with collection in free space.
IP Status
https://patents.google.com/patent/US8674306B2
