Bamboo is an attractive alternative and renewable fuel source compared to fossil fuels. However, there is a requirement for increasing the efficiency and reducing the costs associated with the methods by which bamboo is processed. Bamboo was simultaneously treated by ball milling and hydrothermal pretreatment, using a rotatable autoclave, which is heated by an electric furnace. The product was then enzymatically treated in order to yield glucose. The effects of biomass content, target temperature, and ball loading for the simultaneous hydrothermal pretreatment and ball milling on the product yields were determined. The highest total glucose yield was obtained for biomass loading of 0.10 kg/kg, target temperature of 200 °C, and ball loading of 1.0 kg. The reaction rate parameters were determined based on a reaction network proposed in a previous study. We observed that the ratio of each reaction rate is the same over a range temperature in hydrothermal treatment.
Aqueous solutions (1.0-5.0 wt%) of glycine, which is a model compound of proteins, was gasified in supercritical water using a tubular reactor at temperature of 500-650 °C and pressure of 25 MPa for a residence time of 63-188 s. Activated carbon (0.5 wt%) was employed as a catalyst in order to improve gasification efficiency. The identification and quantification of gaseous products were conducted and the total organic carbon was measured for the liquid effluent. Based on the experimental results, the reaction rate parameters were determined for the carbon gasification efficiency of glycine in supercritical water, assuming a first-order reaction. The results showed that an elevated temperature would be required for achieving high carbon gasification efficiency. The activated carbon catalyst was found to be ineffective for glycine.
Heavy oil becomes more popular as new energy sources due to the current oil prices and enormous amount of heavy oil reserves. However, heavy oil is difficult to produce because of its viscosity. Recently, thermal recovery, like steam injection, is a common method for heavy-oil production. During oil production with steam, crude oils are typically produced as water in crude-oil emulsions. This work investigates the effect of parameters such as temperature, water content in emulsions and shear rate on viscosities and stability of heavy oil and emulsions. It is demonstrated that the viscosity of the emulsions decreases with increasing temperature. Moreover, correlation of the effect of temperature on viscosity has been established and the numerical results get along well with the experimental results. Furthermore, the viscosity of oil enhances with higher water content. In addition, shear rate plays a significant role in viscosity reduction as shear rate increases. Also large shear stress is applied in order to break up the droplet and droplet sizes become smaller and it affects the stability of emulsion.
Microtube reactor with inner diameter less than 1000μm has been widely studied for biodiesel production. High mass transfer rate due to high interfacial surface area and internal circulation flow in a microtube reactor result in a higher fatty acid methyl esters (FAME) yield than ordinary batch wise reactor. The integration of microtube reactor for commercial biodiesel production is highly recommended. To materialize the commercialization goal, different tube size reactors need to be investigated. In this study, transesterification of palm oil with methanol was carried out in a transparent Teflon tubular reactor with an internal diameter of 1.59 mm at 60°C using potassium hydroxide catalyst. The effects of residence time and flow rate on the FAME yield were investigated and the results showed that the FAME yield was greatly influenced by the residence time and was able to achieve 90% at the residence time of about 70 s.
In this study, we have focused on the water-splitting reaction using lithium cobalt oxide LiCoO2 as a hydrogen generation technique. LiCoO2 is known as positive electrode of lithium ion battery. The valence fluctuation of Co and diffusivity of Li are also attractive for the water-splitting. To understand the reaction process, the hydrolysis and regeneration of LiCoO2 are separately investigated and analyzed by using X-ray diffraction measurement, X-ray photoelectron spectroscopy (XPS). XPS spectra of the products after the hydrolysis reaction indicated that LiOH is formed at 300 °C, although the reaction yield is very low. LiCoO2 is synthesized by the reaction between LiOH and Co3O4 at 500 °C. From the results, a possible reaction process of water-splitting by LiCoO2 is proposed.
The civic attention to renewable energy becomes higher and higher after the Great East Japan Earthquake. Moreover, corresponding to such needs, the energy and environmental education also becomes necessary and important. Therefore, we developed the Savonius type windmill aerogenerator as energy and environmental education teaching materials, and used that developed teaching materials for children and teachers of elementary, junior high, and high school as teaching materials. We conducted the questionnaire survey on them and evaluated this developed teaching materials in this case. As a result, we understood, this developed teaching material had high efficiency on studying energy and environmental education. In this paper, the windmill aerogenerator developed by our research and its evaluations are reported.