Hydrogen Contamination Detection

The new purity requirements SAE J7219, ISO 14687-2 and ISO 14687 (Table I and Figure 1 below) place a three orders of magnitude increase on the accuracy of the instrumentation that is necessary to detect these extremely low levels of several critical contaminants. The design and verification of the conceptual approach of a cost-effective and reliable instrument that can sample the hydrogen at the nozzle of a delivery pump, and either certify acceptability or provide a signal to shut off the fuel distribution system is critical for enabling this technology. In addition to the extremely low levels of contaminants that need to be measured, this instrument must be robust and stable over a very large range of temperatures and pressures. While these requirements present formidable challenges in their own right, the requirement for detection and a "go no go" signal execution with a response time of less than 30 seconds may present the most severe obstacle. How Problem is Addressed Sustainable Innovations LLC has teamed with the University of Connecticut Center for Clean Energy Engineering (UConn C2E2) to develop a unique and innovative multi-channel hydrogen fuel quality monitor to detect impurities in hydrogen. The proposed design will operate on stored hydrogen, and will consist of an array of sensors, each tuned to respond to critical concentrations of a specific contaminant defined in SAE J2719. These sensors will each be calibrated at selected impurity concentration values, and the real time measurements will be compared to the fingerprint of these responses. Models, using algorithms verified during this program, will complete an analysis of this data, and provide a go/no-go signal to proceed with vehicular fueling. Phase I The areas of technical development include: alloy / composite catalyst selection for each contaminant; fabrication processes; selection and verification of cell electrolyte; generating a library of electrochemical data; and development and verification of the algorithms required to compare the measured electrochemical data of the test samples to the standards in this library. In addition to these development areas, UConn and Sustainable Innovations will develop the test setup required to evaluate the electrodes. Commercial Applications and Other Benefits The development of a functional hydrogen infrastructure for fuel cell applications requires that hydrogen be able to be delivered to the point of use, such as a dispenser at a refueling station. Guaranteeing delivery of high quality hydrogen to end-users at a reasonable value proposition is critically important. This value proposition extends beyond the delivery and the cost of the delivery equipment as well as the gas involved, it also includes the durability of the fuel cell utilizing the delivered hydrogen. Successful development and deployment of a low-cost hydrogen contaminant sensor will prove critically important in expanding markets for hydrogen used in industrial and energy applications. This activity will also prove important in catalyzing the successful implementation of fuel cell systems.