The entrained flow coal gasifiers, which are adapted for almost all IGCC technologies, are operated under the high-temperature and pressurized condition. It is necessary to clarify the coal behavior in such a condition for the design of the gasifier and the estimation of the gasifier's performance. In this work, the changes of char morphology, such as particle size distributions and bulk density, in the coal pyrolysis or the char gasification reaction were examined using a pressurized drop tube furnace facility (PDTF). Though a lot of pulverized coal particles have swelled by the rapid pyrolysis, the tendency was shown that the initial pyrolysis reaction of a coal with a high fuel ratio was controlled by pressure and the swelling was also suppressed. In the char gasification process, the change of the char particle diameter was few in the early stage of the gasification, because the surface was eroded by the reaction and the pore grew in the surface of char particles. The structure of char particles became fragile and the particles fragmented into smaller parts in the middle and latter stages of the gasification. The numerical model of particle size distributions and particle density of gasified char was proposed to explain the shrinkage and the fragmentation of char particles during gasification, and the validity of the model was shown.
Since the law for concerning the appropriate treatment and promotion of utilization of livestock manure has come into effect in 2004 in Japan, the way of disposal of the manure causes serious waste management problem in rural areas. Production of biogas from the manure by anaerobic digestion is one of the promised technologies to reduce the amount of environmental effect, and to generate heat and electricity. Recently biogas power plants have been installed in rural areas, however, studies on the optimal allocation considering geographic distribution of livestock manure have hardly been investigated. The paper focuses on the optimal allocation of centralized biogas power plants and composting plants considering the distribution of the animal livestock at lower costs, introducing an optimization model and geographical information system. The study also analyzes the effect of the subsidy rate for construction cost on the optimal location of biogas power plants and composting plants.
Woody biomass has become important for a raw material of bioethanol production. Alkaline pre-treatment on the woody biomass is an advantage method for the large scale production of the bioethanol. In this study, the cellulase production using the alkaline treated woody biomass was investigated. And the bioethanol was produced from the alkaline treated woody biomass using cultures of Trichoderma reesei and Saccharomyces cerevesiae. We propose a process of the bioethanol production from woody biomass based on the alkaline pre-treatment, enzymatic saccharification and fermentation.
Equilibrium shifting is considered to be effective for promoting H2 production by ethanol (C2H5OH) steam reforming. In this study, a packed bed reactor with a mixture of reforming catalyst and CO2 absorbent was used. Lithium silicate (Li4SiO4) was applied as the absorbent, which Toshiba has developed. In the case of Li4SiO4, CO2 emission occurs at considerably lower temperature than in the case of the well-known calcium oxide (CaO) and the reaction between Li4SiO4 and CO2 is highly reversible. This is a report of the equilibrium-shift effect on steam reforming of C2H5OH, which was obtained by using Li4SiO4 pellet (ca. 5 mm). Experiments showed obvious effect, which resulted in keeping not only the concentration of H2 at 99.3 dry vol% but also that of CO at 0.11 dry vol% for 0.5 hour. This result indicates the possibility of dispensing with a CO-shift reactor and simplifying either CO removal reactor or purification apparatus, in the case of a reformer using a packed bed of pellets. We believe that it would improve the conventional H2 production system.