No abstract

Pulse Jet - Rechargeable Direct Carbon Fuel Cells (PJ-RDCFCs), in which small amounts of liquid hydrocarbon are supplied by pulse jet, were found to show different power generation characteristics depending on the time interval between fuel pulses (T int). For the T int range studied here (1 to 210 sec), both the maximum terminal voltage during a single cycle and the increase rate just after a fuel pulse can be controlled by T int, and this T int determines the fuel utilization and partial pressure of H2O and CO2. Thus, the gas composition just before a fuel pulse determines the degree of reforming reaction and chemical species contributing to the electrochemical reaction, which affects the power generation characteristics. Power generation at extremely short T int (1 sec) revealed that during pulse jetting, the terminal voltage was stable. Its average power density was 445 mW/cm2, which is high for electrolyte-supported SOFCs that use liquid hydrocarbon.

Pulse Jet-Rechargeable Direct Carbon Fuel Cells (PJ-RDCFCs) in which liquid hydrocarbon is supplied at regular intervals is one application of SOFCs. Most commercial liquid hydrocarbon fuel contains sulfur-based impurities, and thus their poisoning effect on power generation must be considered. In this study, power generation characteristics of PJ-RDCFCs were investigated using supplied fuel containing sulfur over a wide range of fuel-supply interval times (T int: time between fuel pulses). Under both flow-like conditions where T int was short (≤ 5 sec) and pulse-supply condition where T int was long (≥ 10 sec), the power density (P) decreased when fuel with sulfur was supplied. The P of a PJ-RDCFC and the degradation rate evaluated by using hydrogen before and after the power generation had the dependence on T int.

In this study, the genome sequences of two Basidiomycetous yeasts, Tremella yokohamensis and Tremella fuciformis , which have very similar morphological characteristics, were determined. The genomic sequence data obtained will be useful for understanding the taxonomy and metabolic-related genes of basidiomycete yeasts.

Rechargeable Solid Carbon Fuel Cells (RSCFCs) that use directly supplied carbon black (CB) as fuel were developed. The influence of the CO supply rate depended on the CO generation rate and the CO diffusion rate on the power generation was investigated. High power density was achieved by using a larger specific surface area CB fuel due to the increase in CO generation rate. Two types of cell setting were evaluated, horizontal and vertical setting. With horizontal cell setting, densely supplied CB enhanced the power density because the increase in the CO generation rate was greater than the decrease in CO diffusion rate due to the increase of CB surface area per unit column volume. However, CB supply density should decrease during the power generation due to the CB consumption by Boudouard corrosion reaction. In contrast, with the vertical cell setting, CB supply density must be almost constant because CB maintains contact with the anode surface by its own weight. Moreover, the performance of RSCFC was improved by using anode with high porosity. With 27 % porous anode, the maximum power density (PMax ) was 24.1 mW/cm2 at 50 mA/cm2, and with 33 % porous anode, the PMax was 34.6 mW/cm2 at 70 mA/cm2. The total TPB (Triple Phase Boundary) length in anode might be decreased with increasing porosity of anode, but the power density of RSCFC with CB fuel was increased.