Diode Laser Sensor for Contaminants in Hydrogen Fuel

Low concentrations of contaminants in hydrogen fuel can foul or damage fuel cells in hydrogen fuel cell vehicles. Currently there is infrequent monitoring of hydrogen quality at filling stations. There is no instrumentation available to perform this function at the station. In this project, a diode laser instrument is being developed that will be able to perform these measurements at filling stations. The sensor will provide fast measurements so that each vehicle fill can be monitored. In the Phase II project, a prototype was constructed to measure common hydrogen contaminants, carbon monoxide, ammonia, water vapor, and hydrogen sulfide. The system performance was demonstrated at SAE levels for these contaminants. The measurements typically take 10 s for each contaminant. In Phase IIB, the shortcomings of the Phase II prototype will be addressed. The issues include zero drift and contaminant absorption by the sample chamber. After fixing these issues, the prototype instrument will be tested at the CA state quality assurance laboratory. Commercial Applications and Other Benefits: The developed system will be installed at hydrogen stations to monitor fuel quality. It will also be useful for trouble shooting problems in the hydrogen supply chain. The analyzer will be essential to establishing a reliable hydrogen supply for the fuel cell vehicle market which is expected to dramatically increase over the next decade.