In order to assess the impact of the economic growth on the energy structure, the total primary energy supply (TPES) of China in 2010 was estimated assuming that the ratio of energy consumption to the GNP growth is 0.7. This ratio is nearly the average of GNP growth rate in China from 1981 to 1990, after the projection of energy demand of various the sectors, e. g., industry, transportation, and other sectors. Our estimated TPES was then compared with the TPES projected for the same year by the International Energy Agency (IEA) and by the Energy Research Center China (ERCC). As the result of this study, it is clear that the TPES is significantly affected by the assumed energy consumption to the GNP growth ratio. The lower GNP growth projected by IEA and ERCC (between 0.43 and 0.53) resulted in lower in lower TPES estimates, when compared to our predictions. In our estimation, coal will still be one of the main energy resources for China at 2010. If the fractional distillation technology to convert crude oil to gasoline and diesel oil is remarkably improvemed, the clude oil supply will then depend on the demand for liquid fuel for transportation. Therefore the increase in the motorization will likely have a great influence on structure of energy demand and supply in China in the near future.
Flying slag particles have a tendency to deposit and sinter on the exit wall of entrained coal gasifiers. Sintering behavior was examined using water quenched slag and char obtained by the Taiheiyo coal gasification at the pilot plant of HYCOL (Research Association for Hydrogen from Coal Process Development). This plant was designed to gasify 50 tons of coal per day. In this paper the compressive strength was measured and used to estimate the sintering temperature . The sintering temperature of the slag was approximately 800°C, whereas that of the standard JIS ash was 1050°C. It was also found that the presence of carbon in the slag hindered the progress of sintering. When the concentration of carbon in the slag was above 4%, the slag did not sinter even at 900°C. SEM and EDX analyses showed that the carbon in the slag acted as a dispersant. The X-ray diffraction for the cold slag could hardly detect peaks because it was quenched and amorphous. However, the peak intensity of Anorthite detected in the heat treated slag and the JIS ash. The peak intensity of Anorthite was increased with increasing heat treatment temperature and time, but not much affected by the carbon content. This suggests that the slag melts partially regardless of the carbon content, but the carbon hinders the progress of sintering.
A laboratory scale entrained bed coal gasifier was used to study ash melting behavior and the effect of flux addition on the ash melting behavior. Blair Athol coal, Taiheiyo coal and limestone as a flux were used in this study. Ashes produced by char gasification, mostly adhere to the surface of unreacted char particle, and flow together with char in gases flow. Ash adhension to the gasifier wall, ηa, w was increased with the progress of gasification, and was mostly increased around at the exit of gasifier, where char gasification was in the final stage. By the flux addtion, slag (Blair Athol coal, FT > 1873K) melting temperature was reduced to 1613K, when CaO content is about 40wt% in slag. The ratio of flux in slag to the flux added, η was found to about 0.65 in this work. Melting temperature change of slag with flux addition can be explained by the mineral change in slag with a phase diagram for CaO-Al2O3-SiO2 compositions.