Fuel cell is one of the promising candidates for low emission and high efficiency power plant for the next generation vehicles. Currently, general discussions are focused on from where and how to supply hydrogen to the fuel cell stack in a vehicle. Two major concepts are presented; (1) storing pure hydrogen on-board and (2) use of hydrocarbon as a fuel in combination with on-board fuel reformer system to extract hydrogen. Although the reformer idea seems to be rather complicated than the pure hydrogen, the fuel reformer system is very much demanded, due to the energy density of liquid fossil fuel and availability of fuel supply infrastructure. In the development of the fuel reformer system, gas composition measurements are required to achieve (1) efficient hydrogen extraction, (2) low carbon monoxide concentration to protect PEM stack, and (3) low emission. Not only an accuracy of the measurement, but also a fast response time is required since the reformer system tends to be operated transiently.
The present paper discusses the required performance for the gas composition measurement system especially for the fuel reformer. Several technical challenges are addressed to realize accurate and fast response measurement, such as correction for influence from high concentration water and hydrogen. Also, a fast response hydrogen analyzer has been developed with mass spectroscopy technique in combination with a heated NDIR to measure water concentration. The system provides satisfactory performance to the fuel cell reformer development in terms of its sensitivity, accuracy and response time.
Basic performance of the system has been confirmed by use of the standard gas and is shown in the present paper. Practical application has also been demonstrated using a simple fuel reformer and shows promising result for the use in variety of fuel reforming system for the FCEVs.