MEMS Based Sulfur Detection for Logistic Fuel-Based Fuel Cell Power Generators

The proposed work addresses the need to rapidly detect certain sulfur contaminants in aviation fuel vapors to permit continuous operation of hydrodesulfurization units in hydrogen reformers. A sensor design has been developed which will permit differentiation of sulfur contaminants based on differences in the physical characteristics of the gases which affect their adsorption and desorption from certain mixed metal oxide surfaces. The Phase I work is focusing on the characterization of a family of metal oxides which interact strongly with the target gas, dibenzothiophene (DBT), and which are tolerant to the harsh operating environment of the aviation fuel reformer. Accurate mass balance measurements on two of the candidate oxides have shown that the adsorption of DBT is rapid and is sensitive to the partial pressure of the gas at about 100ppm. The sensor, together with associated electronics and embedded software will permit rapid analysis of the target gas. The sensor and electronics will provide a means of re-zeroing the sensor response during use and compensation for changing temperatures over the range of 300-600oC. The sensor will have a goal of 1-10 ppm DBT resolution with a span of 1-400 ppm. The electronic package currently in use requires less than 0.5 Watt.