The etching process by copper chloride is widely used in printed wiring board manufacturing. Unfortunately, almost copper waste solution is treated by neutralization method and the precipitated sludge is dumped on the ground without copper recovery. Brown coal has ion exchange ability because it has carboxy groups and hydroxyl groups in it. Using that ability of brown coal, copper recovery from the waste etching solution by low energy consumption method is studied. Copper ion in the waste solution can be loaded on Loy Yang brown coal around 8.5 wt% by adding ammonium hydroxide, adjusting pH in 9-11.5 and stirring at room temperature. When pH range is in 9-11.5, it is considered that copper and ammonium complex ions such as tetraamminecopper(II) ion [Cu(NH3)4]2+ are produced and exchanged with proton of carboxy groups in brown coal. Cu-loaded brown coal can be burnt at extremely low temperature; 160-180 °C, and 0.5-1.0 μm copper oxide particles are formed as the residue. From XRD analysis at the middle of burning, it is considered that Cu2O plays a role of catalyst of gasification and/or oxidation. It was shown that low energy consuming copper recovery method is feasible by using capability of ion exchange of brown coal and catalysis of Cu-loaded brown coal.
The liquefactions of cellulose, rice straw, and red pine were conducted in a batch reaction system in the presence of solid catalysts and several protonic solvents, such as methanol and ethylene glycol. In the solvolysis of cellulose in methanol, methyl-glucopyranosides were the main products formed via the addition of H+ and OCH3– in the presence of a solid catalyst. The decomposition rates of cellulose in various solvents decreased in the order of water › methanol › ethylene glycol › 1-butanol. This may suggest that the solvents with large self-dissociation constant (KSH) enhance the solvolysis of cellulose. In addition, the pore structure and acidity of a solid acid catalyst and type of lignocellulosic biomass also affected the solvolysis. The maximum liquefaction rates of rice straw and red pine in ethylene glycol using a sulfated zirconia catalyst at 453 K for 6 h were ca. 78.7% and 97.5%, respectively.
The life cycle assessment of lithium-ion (Li-ion) rechargeable battery was evaluated by charge and discharge processing. The influence of the temperature was studied during several hundred cycles of charge/discharge process of Li-ion battery. The charging capacity was observed to be decreased with increased number of cycle, especially at higher temperature of the environment of 60 °C. The cathode of Li-ion battery was found to be affected by heat stress and charge/discharge cycles by XRD analysis. The GC-FID and GC-MS studies revealed that the diethylfluorophosphate (DEFP) is a degraded product of electrolyte. Though the decomposition of ethylene carbonate (EC), a major component of the electrolyte in the Li-ion battery was not clearly found, the relative area of DEFP to that of EC was found to be increased with increased charge /discharge cycle number at 60 °C.