SBIR-STTR Award

Ion Optics proposes to develop a MEMS based, non-dispersive infrared (NDIR) spectroscopic instrument to measure the sulfur content of the hot gas stream feed for the fuel cell. Prototype laboratory instruments have demonstrated the specificity and sensitivity of this technique to measure the carbon monoxide concentration in 100,aC phosphoric acid fuel-cell feeds from reformed gasoline under conditions that caused rapid failure of all electrochemical sensors. This Phase 1 research will demonstrate detection of sulfur at sub-25ppm levels at 400,aC in less than one second using NDIR technology. Test gases will include feed stock with appropriate potential interferents (CO, CO2, H2O, and hydrocarbons). Ion Optics is developing a prototype MEMS device for NDIR spectroscopy that combines the functions of light source, detector and optical filter onto one chip. Phase I results and specifications will define the necessary modifications to the chip for detecting low-concentrations of sulfur in high-temperature reformed-fuel streams. Optimized MEMS devices would be available for use in Phase 2 deliverables for Air Force testing.

Benefits:
The proposed optical sensor is not in direct contact with the vapors being tested, making it very reliable with a long lifetime for protecting fuel cells from damage due to contamination of the vapor feed. If diesel fuel-based fuel-cells for large vehicles become commonplace, e.g. the hydrogen economy, very many copies of this product would be required. Another immediate potential commercial application is detection of sulfur in natural gas sources.

Keywords:
Gas sensor Infrared spectroscopy Fuel cells

This Phase II SBIR project aims to develop an infrared (IR) spectroscopic sulfur sensor to be used by the USAF on fuel cell-based, ground power generators using JP-8 fuel. This fuel grade typically contains 300-400 ppm sulfur, and removal of this contaminant is critical to efficient operation of the solid oxide fuel cell (SOFC). These generators need in-line sensors to monitor sulfur content at concentrations below 10 ppm. The objectives of the Phase II are to design, fabricate, test, and demonstrate a prototype sensor operating on a JP-8 fuel processor for SOFC. Phase I proved the feasibility of an innovative non-dispersive infrared spectroscopic (NDIR) method, employing a highly-compact, folded-path optical design, by selectively and accurately detecting test vapors under ambient conditions. Phase II will improve sensitivity and resolution to 1 ppm in de-sulfurized JP-8 process streams in the high temperature (400-600C) process environment. The prototype sensor, electronics and software will be delivered for testing on a prototype system at USAF facilities.

Keywords:
Gas Sensors, Spectroscopy, Ndir, Sulfur, Dibenzoth