We have to keep our energy use for room heating in winter season which is just the same situation as food of human being in cold regions. However, it is not so clear for our recent research target to keep the energy resources and check its saving system. If we consider the living style in warm or hot regions, it is possible to neglect the energy use of room heating, but not to neglect it in cold regions. Therefore, we have to discuss how to keep the energy resources and how to check the energy conservation and environmental pollution. When we consider the effective use of unutilized energy for the above items, the largest one will be a summation of exhaust energy from each consummer of domestic site, industry site or traffic site. This exhaust energy may be occupied by 50 percent or more of total energy consumption. Then, it is necessary to develop a technical system of its effective use and to select a moderate hardware for the above operation. Now, many national projects have been introduced to develop the effective use of unutilized energy and support its application.
Influence of alkali metal compounds on desulfurization characteristics of sea-shell and limestone was elucidated quantitatively by using a thermobalance in this study. Scallop removed alkali metals and chlorine and Tsukumi limestone added several alkali metal compounds and chlorides were used as a sample. In order to elucidate additive effect of sodium chloride into the limestone on the desulfurization characteristics, the mean pore size by a pore sizer, the sulfur distribution within a reacting particle by an EDX system and the crystal structure of particles by a XRD system were measured. As a result, the desulfurization efficiency for the scallop even after removing the alkali metals and chlorine little changed. The addition of sodium chloride into the limestone can increase the desulfurization efficiency best. Both the mean pore size and the crystal structure of the calcined limestone, into which sodium chloride was added, was similar to those of the calcined scallop.Thus the desulfurization reaction produced over the whole of a particle. However, even if sodium chloride was added into the calcined limestone (CaO), the desulfurization efficiency was not promoted.
Reactivity of coal chars to carbon dioxide at high temperatures of 1273-1873K was investigated using a fluidized bed reactor (FBR). Coal samples were pyrolyzed in nitrogen flow under rapid and slow heating condition, and then in-situ measurement of gasification rates of the prepared chars was carried out. It was found that the heating rate during the pyrolysis affected the reactivity of coal char significantly, namely, more rapid heating led the higher reactivity of chars. Especially for coals with high volatile content, the reactivity of coal chars prepared under the rapid heating was several times as large as that under the slow heating. The results of nitrogen adsorption measurements indicate that porosity and surface area of mesopores were proportional to the reactivity of chars. The high gasification reactivity of rapid heating chars can be explained by their high surface area in mesopore range.
This study attempts to develop a clean and high efficiency combustion system utilizing reactions in supercritical water. This study is aimed at the establishment of the measuring techniques of transport properties of gas and observing techniques of reaction zone in supercritical water. The refractive index of water in supercritical region was measured first because previous values were not available. The measurements were made under the conditions from ambient temperature to 420°c and from atmospheric pressure to 27MPa. The results showed that the index was constant at the whole range of the condition within experimental errors. The mass diffusivity of gas in supercritical water was measured on the assumption that the mixture was an ideal mixture. Nitrogen was employed as an alternative media of oxidizer gases in this experiment to avoid the effects of reaction. The mass diffusivity of nitrogen in supercritical water was calculated from the fringe shift measured by a Mach-Zehnder interferometer. The value of the measured diffusion coefficient was intermediate between gas and liquid's one. The effect of excess volume phenomena on the diffusivity was discussed using the experimental results.