Purpose of our study is to obtain the detail information about the occurrences of micro-explosion in a burning emulsion droplet with ethanol additive. n-Hexadecane in water emulsions doped with surfactant and ethanol additives were prepared as test fuels. Combustion experiments are made for a test droplet suspended at the tip of a quartz filament in a quiescent air environment. The base fuel and surfactant content were 0.7 and 0.03 by volume respectively. Ethanol content is varied from 0.0 to 0.08 by volume. Time histories of droplet temperature is measured by thermocouple of 0.025 mm in diameter. Phase separation process of test emulsion suspended in glass tubes immersed in oil bath is also discussed. The Weibull analysis is applied to obtain the distribution function of the waiting time for occurrences of micro-explosion and to determine the mean waiting time for micro-explosion. AE signal of micro-explosion was measured simultaneously and discussed the relative intensity of micro-explosion as a peak voltage of AE signal. The results showed that the distribution function of the waiting time for occurrences of micro-explosion are correlated to the Weibull distribution, classified to the wear-out type of its shape parameter of 2.0. It is also concluded that mean AE peak voltage of micro-explosion correlated with droplet temperature. Effects of ethanol addition on mean waiting time for micro-explosion and internal phenomena in a burning droplet were also revealed.
To elucidate fundamental combustion behaviors of some solid combustible wastes, the isothermal combustion experiments are carried out, using an electrically heated vertical batch furnace. The effects of the furnace temperature and the oxygen partial pressure in the reaction atmosphere on the combustion behaviors are studied experimentally and kinetically. Comparing the experimental results obtained with the kinetic modelling results, the most optimum kinetic model is proposed for all of the samples employed, and the detail combustion mechanisms are also elucidated quantitatively. As a result, the completion period of the overall combustion decreases with increases of both the furnace temperature and the oxygen partial pressure. The evolution period of volatile matter (VM) is reduced in order from the bituminous coal, the oil coke to the waste plastic of composite materials. While, the reaction period by 95 % of the conversion is shorten in order from the oil coke, the waste plastic of composite materials and the bituminous coal. The reaction model for the oil coke is revealed as the parallel model of the volumetric model with the grain model. For both the waste plastic of composite materials and the bituminous coal, the parallel model the volumetric model of with the pore model agrees well with the respective experimental results. The activation energy of the fixed carbon (FC) combustion for the oil coke is the largest of the three. The activation energy for the waste plastic of composite material is almost the same as that for the bituminous coal. The reaction orders of the oxygen partial pressure for the VM evolution and the FC combustion become almost 0 and 1 for all of the samples, respectively.
This study discuses a versatile method to estimate the socio-economic impacts by region (i.e. prefecture, nation, and the world) of introducing energy technologies using Input-Output (IO) tables. The study builds two types of models from national and prefectural IO tables: a difference IO (DIO) model, and a two-region IO (TRIO) model. Both models reflect the industrial structures in two regions and can analyze the socio-economic impacts in the three regions. These models are tested in a case study on Japan’s Yamanashi prefecture, where they estimate the economic impacts of a renewable energy power generation across the life cycle. The case study results show no significant differences of the impacts in the prefecture at the construction, operation and maintenance stages between the two models. However, at the manufacturing stage, the TRIO model shows a slightly higher impact than the DIO model. This is because the TRIO model reflects the rebound effect unlike the DIO model, and the rebound effect is greater in the manufacturing sectors than in the other sectors. While the DIO model have a slightly lower accuracy due to not considering the rebound effect, it is better than the TRIO model in that it can easily estimate the impacts.
Non-supported nanoparticles exhibited novel and unique catalytic performances in some reactions. The nonsupported cobalt nanoparticles (Co NPs) colloidal suspension was directly used as catalyst for hydroformylation reaction of 1-hexene, to investigate the difference of catalytic performance between non-supported Co NPs and supported Co catalyst (Co/SiO2) for aldehyde synthesis. The Co NPs exhibited higher activity on the hydroformylation and selectivity of heptanal than supported Co/SiO2. The higher hydroformylation performance could be contributed to the higher metal surface and larger amount of active sites of non-supported Co NPs, without the coverage of support.
A kinetic study of the catalytic degradation of rapeseed (Brassica napus) oil over MgO has been performed in a 70 cm3 batch reactor using a 2k factorial level experimental design. This study predicted the parameters that affected the liquid yield and the highest selectivity for naphtha. The optimal operating conditions were a temperature of 390 °C, a hydrogen gas pressure of 3 bars, a reaction time of 60 minutes and MgO catalyst content of 0.5 wt%. These conditions gave a yield of 85.33 wt% and 32.04 wt% liquid fuel and naphtha, respectively. From an analysis with a simulated distillation gas chromatograph and a gas chromatograph/mass spectrometer, the distribution of liquid fuel was found to be C5-C12 aliphatic hydrocarbon molecules, 9.49 wt% alkane and 50.62 wt% alkene. FT-IR analysis showed C-H (stretching) indicating the presence of aliphatic hydrocarbon compounds (among the main functional groups), represented by the obvious peak at 2850-3000 cm-1. The physicochemical parameters identified pyrolysis oil, which has an acidity of 1.49 mgKOH/mg and a heating value and kinematic viscosity of 44.93 MJkg-1 and 0.99 mm2s-1, respectively. The temperature contributed to the decomposition of triglyceride acid by secondary catalytic cracking, and the acid active sites on MgO produced a biofuel that was used as an alternative fuel. Furthermore, the kinetic parameters were also determined to be second order. The activation energy (Ea) and the pre-exponential factor (A) from an Arrhenius relationship were also defined as 71.134 KJ mol-1 and 18.21 s-1, respectively.
A large amount of Konjac flying powder (Tobiko) is generated in the manufacturing process of Konjacderived products, which are popular Japanese traditional foods. Almost all of the Konjac flying powder is discarded because it currently has minimal effective utility. The aim of the present study was to produce bioethanol, a form of biomass energy, from Konjac flying powder to establish an effective application of this waste product. First, polysaccharides contained in Konjac flying powder were decomposed to monosaccharides (e.g., glucose) by sulfuric acid, hydrochloric acid, or nitric acid. Second, ethanol was generated from the monosaccharides by fermentation and refined by single distillation. Components analysis was performed with high-performance liquid chromatography and gas chromatography at each step: saccharification, fermentation, and distillation. The results revealed that ethanol (9.1 g/L, 600 mL, before distillation) could be successfully produced from Konjac flying powder (30 g) similar to other food industry waste products. In conclusion, we have demonstrated bioethanol production as a new manner of utilization of Konjac flying powder, in addition to its use as fertilizer and livestock feed.