Vol.4 No.2 2011

Research paper−99−Synthesiology - English edition Vol.4 No.2 pp.99-107 (Oct. 2011) concentration range, detection limit concentration, and performance such as selective gas detection. Most of the reports at related academic societies are concerned with materials research and device research and present arguments based on these detection performances. However, for sensors to be used in a real society, economy and reliability are required in addition to the detection performances. In particular, reliability is a subject that is most severely questioned when applied to a real sensor system.We have developed a novel hydrogen sensor by continuously providing solutions to these challenges, the results showing the best performance in hydrogen leak detection applications. In terms of social receptivity of actual application of this sensor, we also have proposed international standards for hydrogen detectors.2 Social demands for performance of hydrogen sensorsTo ensure clean, safe to use hydrogen without the danger of its explosion, safety warranty technology is essential. At hydrogen-related facilities that require a high level of safety management such as hydrogen stations, hydrogen sensors are required to monitor changes in the concentration of hydrogen leaks continuously. In the hydrogen stations, large quantities of hydrogen are stored and frequently transferred to hydrogen cars, and the new technology of safe management of the stations is a challenge for a clean energy society. It is time to review the weaknesses of the current technology of safety sensors described below.Most of the commercially available hydrogen sensors are 1 IntroductionIt was only 10 years ago in 2000 that we began the research and development of a new hydrogen sensor of thermoelectric principle presented in this paper. With the reorganization of the research environment into the National Institute of Advanced Industrial Science and Technology (AIST), we, the researchers working on material science and engineering explored the future of new materials research. The R&D level of leading industrial manufacturers or private sectors was already high, especially on devices, and also the process facilities and analysis equipment were highly advanced. We have tried to find the answer to differentiate ourselves from the basic studies of the materials in the university laboratories and we attempted to use new functional materials in the production of sensor elements or devices.At the same time, a hydrogen-energy technology boom occurred, led by hydrogen fuel cells. For the goal of establishing a better leak detection sensor technology, which is the most important for the safe use of hydrogen, a novel sensor of a new working principle was developed in our laboratory. It is a “fusion of knowledge” of catalytic combustion gas using a catalyst which is the operating principle of a flammable gas, and a thermoelectric material being researched at that time. With a new principle of thermoelectric materials converting the local temperature changes caused by internal heating from burning gas to voltage, we jumped into the field of hydrogen sensors where so much had been developed up to that point.Not limited to hydrogen sensors, a variety of performances is required with gas sensors. First of all, there are the detected - Technology to secure safety in hydrogen usage and international standardization of hydrogen gas sensor-Woosuck Shin*, Maiko Nishibori and Ichiro MatsubaraAdvanced Manufacturing Research Institute, AIST 2266-98 Anagahora, Shimo-Shidami, Moriyama-ku, Nagoya 463-8560, Japan *E-mail : Original manuscript received February 1, 2011, Revisions received April 26, 2011, Accepted April 27, 2011A thermoelectric hydrogen gas sensor developed for leak detection in hydrogen stations has shown good hydrogen selectivity and wide hydrogen detection concentration ranging from 0.5 ppm to 5 %. We have demonstrated high sensitivity and reliability of the sensor exceeding conventional technology through a field test of one year. We could optimize the following three constituent technology elements to meet the social needs, i.e. new principle integrating catalytic combustion and thermoelectric conversion technology, micro-fabrication technology to realize the principle and high performance ceramic catalyst for gas combustion. In addition, the sensor performance evaluation technology established during the development has been proposed for ISO standardization.Thermoelectric hydrogen gas sensor Keywords : hydrogen sensor, hydrogen station, field test, thermoelectric, catalyst combustor[Translation from Synthesiology, Vol.4, No.2, p.92-99 (2011)]


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