Misa Watanabe

Electrochemical Power Generation Directly from Combustion Flame of Gases, Liquids, and Solids

The performance of a solid oxide fuel cell fueled with flames of combustible gases, liquids, and solids was studied. A cell structure in which cells were serially integrated within a disk was also examined. Open-circuit voltages indicated with a single cell and the integrated cell were ∼0.8 and ∼3.5 V, respectively. Maximum power density obtained with the flames of n-butane, kerosine, paraffin wax (candle), and wood were respectively 75, 65, 62, and 5 mW/cm 2 . The integrated cell gave a maximum power density of 318 mW/cm 2 with n-butane flame. Fuel to air ratio distinctly influenced the output.

SO2 gas sensor utilizing stabilized zirconia and sulfate salts with a new working mechanism

Abstract A solid-state gas sensor for sulfur dioxide with a new working mechanism was fabricated and its sensing properties investigated. The sensor was constructed using yttria-stabilized zirconia as the oxygen ion conductor, silver sulfate based salts as the auxiliary phase, a silver sensing electrode and a platinum reference electrode. When sulfur dioxide was detected, the potential of the sensing electrode changed to negative with the new working mechanism. The 90% response time of the sensor to 100 ppm SO 2 was ca. 40 s at 600°C, and the electromotive force (EMF) value obtained was perfectly linear to the logarithm of SO 2 concentration over a wide range (1 to 1000 ppm). The Nernst’s slope corresponded exactly to the theoretical value based on a two-electron electrochemical reaction.