In this work, we investigated the influence of adding a chelating agent, nitrilotriacetic acid (NTA), on the morphology and activity of spherical silica-nickel composite particles for hydrolytic dehydrogenation of ammonia borane. Their particle sizes prepared with NTA decreased with increasing pH value of the solution used to form the composite particles. The homogeneity of the composite particles prepared with NTA increased with increasing pH value. The hydrogen evolution rate and amount from the aqueous solution containing sodium borohydride (NaBH4) and ammonia borane (NH3BH3) in the presence of the composite particles prepared with NTA did not significantly depend on the pH value. On the other hand, the size and homogeneity of the composite particles depended on the ratio of nickel to NTA. The nickel content of the composite particles increased with increasing the ratio of nickel to NTA, and the composite particles with high ratio of nickel to NTA showed high activity for hydrogen evolution from the aqueous solution containing NaBH4 and NH3BH3. From this and energy-dispersive X-ray spectroscopy (EDX) results, it is suggested that the spherical silica-nickel composite particles prepared with NTA included highly dispersed active nickel species, and showed high activity for hydrogen evolution from aqueous solution containing NH3BH3.
The use of drones in logistics is accelerating. However, there is a problem with the duration of batteries in that the capacity is insufficient. Owing to this, a serious problem would be caused by an expansion of the delivery area. Manufacturers of batteries are trying to increase the capacity, while global-warming protection is necessary. Thus, renewable energy and/or the more-efficient batteries, such as the fuel cell (FC) battery, are promising countermeasures. In this research, an FC battery fueled by Bio-H2 from biomass feedstock was investigated. Using the demo drone, the Li-ion battery and FC battery were compared in terms of the eco-burden on the basis of a life cycle assessment approach. Here, through flight tests, the relationship between output and payload was evaluated. Then, with the FC battery with storage mounted on the drone, the performance was evaluated. The FC battery bearing the storage carries, metal hydride, is still under developing toward improving the performance.
To evaluate mercury partitioning in a coal-fired power plant and to investigate the influence of the configuration of gas treatment facilities on mercury emission, data sets of mercury concentration in coal, coal combustion residues, wastewater, and stack gases were collected from 44 coal-fired power plants in Japan from 2001 to 2014. The mean mercury concentration in coal, measured from 1224 samples, was 0.039 mg/kg, while the mean emission rate, measured from 259 samples, was 3.63 μg/kWh. The total annual mercury emission from coalfired power plants in Japan, which was calculated using the mean emission rate, was 1.0 t. The mercury removal efficiency was found to be improved by decreasing the electrostatic precipitator (ESP) operation temperature and by implementing selective catalytic reduction (SCR). The combination of SCR, advanced low-temperature ESP, and flue gas desulfurization (FGD) showed a high mercury removal efficiency of 87.4% on average.
We have developed an analysis method of carbon components in carbon composite materials through selective gasification, based on their differences in crystallinity and reactivity with steam as a gasifying agent. This paper shows the results of application of the method to two different types of carbon composite materials: carbon fiber composites and anode electrode materials for lithium-ion batteries. Using this method, we successfully quantified the amount of each carbon component in the carbon composites with high accuracy. The technique described in this paper has a potential not only for quantitative analysis of carbon composites, but also for evaluation of microstructures of carbon products, such as carbon fibers, needle cokes and so on.