Hydrogen Production by Microwave Steam Reforming

An ultrahigh-speed heating method of greater than 100 degrees C/s was developed using the microwave irradiation. This method was achieved with a single-mode cavity and absorbent materials that can concentrate the microwave energy. We report a new fuel reforming using bioethanol and microwave heating. By the steam reforming of ethanol using microwave, only a catalyst layer is preferentially heated from the inside for a short time, and so it becomes possible to quickly reform with a simple setup and provide a high energy efficiency. 4.7 mole of hydrogen from one mole of ethanol could be constantly produced within 20 s. Full conversion of 100 % was obtained at low temperatures and high gas space velocities. Activation energies for the microwave process decreased about 30 % compared to the conventional one. Advantages of the microwave over conventional one became clear. This innovative microwave process will be used for on-board vehicles and contribute to CO2-free technologies.