High temperature gasification experiment of woody biomass was carried out in an entrained down flow gasifier. In this experiment, characteristics of gasification residue in a high temperature gasification process were clarified. The highest temperature of gasifier was over 1273 K. Gasification experiment was conducted at different feed stock feeding rates, and gasification residue was collected during the gasification experiment at various dust collection points. Collection point of gasification residue was the gasifier exit, gasifier bottom, cyclone and bag filter of the gasification unit. Characterization of residue was conducted by chemical composition, particle diameter and particle shape. Temperature distribution in the gasifier and produced gas composition was monitored during the gasification experiment. Chemical composition of collected gasification residue was different at different dust collection points. Ash content was the highest in the gasifier bottom residue, and fixed carbon content was the highest in the bag filter residue. Particle diameter and observed particle shape was also different at different dust collection points. Gasification temperature increased with increasing the feeding ratio, chemical composition and particle diameter of residue was changed drastically. Ash ratio increased in the gasifier bottom, and fixed carbon ratio increased in the bag filter. But the differences in particle shapes collected at the same dust collection point were not significant. Calculated carbon conversion values didn't show the big difference in different experimental conditions, but gasification behavior in the gasifier was different, and soot generation increased with increasing the gasification temperature.
The purpose of this study is to improve accuracy of the renewable energy assessment in order to promote renewable energy utilization. We have a local renewable energy assessment in the local new energy vision by NEDO. But NEDO assessed potential of local renewable energy with different methods for different energies. Some of these assessments are not accurate enough to decide policy for promoting renewable energy. Therefore, the authors developed a new method of renewable energy assessment and improved the assessment more systematic and accurate by using GIS. The new method evaluates amount of renewable energy as frequency distribution and shows spatial distribution of renewable energy. The authors applied the new method to Unzen City in Nagasaki Prefecture as an example and showed availability of the new method. The result showed that Unzen City has practical potential of 45MWe for geothermal energy, 7.6 MWe for wind energy, 1.1MWe for solar energy and 1.7MWe for small-scale hydropower as a most probable value and that wind and geothermal energy are concentrated to the specific areas and hydropower and solar energy are distributed in whole Unzen City.