The present study investigated catalytic properties of palladium nanoparticles for hydrogenation of carbon dioxide into formic acid and effect of silica-coating on the palladium nanoparticles to maintain stability of the nanoparticles. The nanoparticles were obtained from palladium nitrate dissolved in methyl alcohol solvent under solvothermal conditions, and the activity for the hydrogenation reaction was evaluated under various reaction conditions. Reaction pressure influenced turnover number (TON) of the nanoparticles for hydrogenation of carbon dioxide into formic acid, and the TON significantly decreased with increasing reaction time under high reaction pressure. UV-Vis spectra of the solution after the hydrogenation reaction indicated that larger amount of active palladium species dissolved in the reaction solution under higher reaction pressure. In order to prevent the active palladium species from dissolving into the reaction solution, we investigated effect of silica coating on the palladium nanoparticles. Thicknesses of silica coated on the nanoparticles by sol-gel based method were controlled by adjusting amount of tetraethoxysilane (TEOS) using as the silica source, and addition of appropriate amount of silica was effective to prevent the active palladium species from dissolving into the reaction solution during the hydrogenation reaction. In addition, the silica coated catalyst possessed good recycle ability for the hydrogenation reaction.
Renewable energy has been developed in Japan to actualize the sustainable society. It is also expected to contribute rehabilitation razed by Great East Japan Earthquake. Iwate prefecture has great wind resources potential among disaster-stricken areas. We have evaluated the wind energy by wind turbines in Iwate prefecture with Geographic Information System (GIS) taking into account restriction for the plant location and business feasibility. Furthermore, we have analyzed sensitivity analysis of feasibility and assessed the case of bigger or less expensive wind turbines. As the results, wind power in Iwate prefecture has capable of generating 73.4 TWh for one year with the levelized cost of 24.7 Yen/kWh. For the location which has above 8% of the internal rate of return (IRR), the total amount of annual electricity and the levelized cost are estimated to 3.0 TWh and 15.4 Yen/kWh, respectively. The available area is 232 km2 and this accounts for only 1.5% of the whole. The improvement of IRR is expected by the installation of larger wind turbines, though the available area increases only slightly with the cost reduction case.
Non-wood lignocellulosic biomass is a promising raw material that can be converted into glucose for cellulosic ethanol production. Since pretreatment could improve the enzymatic saccharification of lignocellulosic biomass, a comparison of enzymatic hydrolysability among different pretreated non-wood biomasses was presented in this study. Results showed that although the non-wood biomasses, namely kapok, EFB and kenaf core fibres were treated by same pretreatment condition, the enzymatic hydrolysability of these pretreated biomasses was different. This was highly related to the changes of chemical composition in the biomasses after pretreatments. Moreover, the total glucose yield (TGY), which was calculated by multiplying the enzymatic saccharification yield with the solid recovery yield of the pretreated biomass, played an important role in evaluating the effectiveness of pretreatment on the enzymatic hydrolysability of biomass. Besides, TGY could indicate the total amount of glucose that could be attained from a basic weight of the untreated biomass. Hence, the study found that besides the enzymatic saccharification yield, the solid recovery yield was also essential for cellulosic ethanol study as it was affected by the loss of the cellulose during pretreatments.
Internal Circulation Fluidized Bed Boiler “ICFB”, which has been developed by KAWASAKI, is capable of firing various types of fuels, such as refuse derived fuel and wastes including corrosive components. The fluidized bed of ICFB is divided into “Combustion Cell” and “Heat Recovery Cell” by using “Double Partition Wall” and the bed material circulates internally by the differential air flow of each cell. The ICFB which has been supplied to Jeonju Paper Corporation (Jeonju City in Korea) is 131 t/h of steam generation by waste wood firing, that is the maximum capacity of ICFB, and electric power generation of 33 MW has been verified. The ICFB can substantially make a contribution to the effective utilization of renewable energy (woody biomass) and CO2 reduction.
Microcrystalline cellulose (MCC) was extracted from two types of oil palm trunks (OPT) fibers. The first sample was the leftover of OPT fibers after the sap was being squeezed out while the second sample was the leftover OPT fibers after the starch was being extracted. The chemical compositions of the two types of OPT fibers were analyzed using TAPPI standards for their extractives, holocellulose, α-cellulose, and lignin contents. Several analyses were carried out including scanning electron microscope (SEM), zeta potential, X-ray diffraction (XRD) and thermogravimetric analysis (TGA) to determine the morphological, dispersion stability, crystallinity and thermal stability of the OPT fibers, respectively. Some changes were observed on the surface of oil palm trunk fibers and intensities in the sample spectra after acid hydrolysis. The XRD results showed an increase in crystallinity value and reached 65% after acid hydrolysis for both MCC compared to their raw OPT fibers. The TGA results of both samples MCC exhibited lower thermal stability after acid hydrolysis compared to the raw OPT fibers. The obtained MCC has a potential to be used in high composite material processing.