Combustion Characteristics of Hydrogen in a Catalytic Fluidized Bed

Abstract

A lot of researchers expect hydrogen to become a clean energy carrier in the future, and are advancing the development of the fuel cell that can effectively generate electricity by using hydrogen. When high concentration hydrogen is intermittently exhausted from the fuel cell system, it is necessary to develop the processing system of the residual hydrogen at the same time. Therefore, we have focused on a catalytic fluidized bed reactor with a heat exchanger which can control the bed temperature and have investigated the catalytic combustion reaction of hydrogen with platinum particles in the fluidized bed reactor. As our investigations, the hydrogen conversion was increased with the bed temperature, more than 99.8% above 150°C. Although the hydrogen conversions below 60°C were influenced by initial hydrogen concentration and hydrogen gas flow rate, the hydrogen combustion rate was roughly increased with space velocity of hydrogen gas. Additionally, under the low temperature, the condensation of product steam in the catalytic bed was an important operating parameter. To achieve higher conversion, the bed temperature is expected to be controlled about 150°C. Then, 80% of product heat can be recovered by a water cooling tube.