In order to make up a simulator to support the development of coal partial hydropyrolysis process, material balance of the reaction was investigated precisely. Amount of H_2 evolved by pyrolysis under inert gas atmosphere was found almost equal to that of (CO+2CO_2), therefore, most of H_2 seemed to be generated through water gas reaction and shift reaction. CH_4 seemed to be stable even at 1073K and 7.1MPa of H_2, its generation was simply accelerated in proportion to H_2 pressure. Hydrocarbons, other than CH_4, were fundamentally unstable at 1073K and 0.93-7.1MPa of H_2, however the rate of decomposition of them were so slow that amounts of them evolved were apparently proportion to reaction time and H_2 pressure. BTX and naphthalene were increased apparently with H_2 pressure when the reaction time was less than 5s.

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Pyrolysis reaction rates of carbonization gas have been determined with 13 coal blends in recent coke-making process. It was confirmed that the rate increases with the increase of the volatile mater. It was suggested that the rates are closely related to the oxygen content of coals and tar yields. That is, the rate increases with increasing tar yields and decreases with increasing oxygen content in coals.

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It is very important to examine the mechanism of coal pyrolysis under high pressure and high temperature for designing and operating entrained-bed type coal gasifier. We have recently found that the solid particles (residue) produced under rapid heating of bituminous coals to over 1000℃ at 〜2MPa consisted of so called char and coke. This means that the reaction forming coke from volatiles proceeded within coal particles under the operating conditions. This was presumed to be caused because the rate of coke forming reaction is larger than the volatilization rate of tar components in nano space of coal particles under the operating conditions. To confirm the presumption, pyrolysis of tar components adsorbed on several porous materials was performed using a pressurized curie point pyrolyzer that can be heated up to 1040℃ at the rate of 3000K/s under 〜2MPa.

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The effect of petroleum coke addition to coal charge on the resultant coke qualities was investigated using a coke test oven. Addition of the petroleum cokes into coal charge, in the range from 1 to 5 mass%, deteriorated coke qualities, especially coke strength evaluated by the drum index regulated in K2151 in JIS, DI^<150>_<15>, and the coke strength after the reaction with carbon dioxide, CSR. However, further crushing of the petroleum cokes was found to lead to suppression of the drop in DI^<150>_<15> and CSR. On the other hand, the petroleum coke addition had benefit to increase the coke yield due to the low volatile matter content of the petroleum cokes. The sulfur content of the petroleum cokes was found to remain mainly in the resultant cokes after carbonization. Therefore, the increase in sulfur content of the resultant cokes must be taken into consideration when the coke is used in a blast furnace.

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In order to develop an efficient absorbent for SO_2 in coal combustion, coal char-supported CaO was prepared from oyster shell in the presence Yallourn coal. Illinois No.6 coal was combusted by admixing the absorbent in a fixed bed reactor at 900℃. Performance of the absorbent was evaluated by the SO_2 concentration in the tail gas. In Illinois No.6 coal combustion without the absorbent about 710ppm of SO_2 was released. When the absorbent was mixed with Illinois No.6 coal (Ca/S=3), the SO_2 concentration in the tail gas decreased to 10ppm.

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The direct synthesis of carbon nanotube (CNT) from coal was examined by chemical vapor deposition (CVD) method. Under selected conditions including the reaction temperature and the amount of catalyst, CNT production from coal was successfully achieved. Based on the results of the experiments with several coal samples, the effect of the production conditions on the yield and property of CNT was discussed.

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For the rehabilitation of a coal preparation plant at Ombilin Coal Mine in Indonesia, we have focused on the establishment of a system that is capable of automating the current type of quality control system and of controlling them on-line. The way in which this is achieved is to measure the ash content of the float products from jig separator continuously in an on-line fashion so as to control jig operation in accordance with the signal output We try to model the jig operation to develop a control system using fuzzy modeling. This system permits efficient quality control of the float products from the jig and resolves the problems of unsteady control.

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The yields of pyrolysis products (tar and gas yields) of herbage biomass can be estimated by atomic ratios. The gasification rate of biomass char, which is 100 times higher than that of coal, increase with the increase in pressure.

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Rapid Pyrolysis of woody biomass was studied using a drop-tube furnace (DTF) in the temperature range 600 to 1400℃. Special attention was paid to the effect of pyrolysis temperature on carbon conversion, gas quality, tar formation, and coke deposition. An important observation was the decrease in carbon conversion from 900℃ to 1200℃ followed by a sharp increase as the temperature was raised to 1400℃. Tar content decreased with the increase of pyrolysis temperature, and an almost tar-free product gas was achieved above 1200℃. Apparent coke deposition occurred above 1200℃ accompanied by the second decomposition of tar and light hydrocarbon gas species.

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Emission of PM_<10> from co-firing of coal and cedar was investigated. The reaction conditions were selected as: 1450℃, air and a residence time of ca. 3 seconds. The results indicate that, for the combustion of cedar alone, many PM_1, was produced consisting of condensed metallic vapors. During the co-firing of coal and cedar at a mass ratio of 90:10, little changes were observed for PM_<10>. With the proportion of cedar increased, less PM_<10> was however emitted since more the larger aggregates were formed through the interaction between coal minerals and cedar minerals

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The production of light fuel gases by catalytic gasification of sewage sludge at low temperatures was investigated. Steam gasification of sludge was carried out in the temperature range of 773-973K with two stage fixed-bed reactor in argon atmosphere. When the nickel catalyst was used, tarry materials were remarkably reformed and the yield of the gas increased. The main component of product gas was hydrogen. The reforming of tarry materials progressed at temperature as low as 773K using Ni-catalyst.

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We carried out low temperature catalytic-gasification of feces of domestic animals which were beef cattle, dairy cattle, swine and chicken. Gasification experiments using two-stage fixed-bed reactor in argon and steam flow were performed. One gram of each samples were bedded at upper stage, and catalyst (Ni/Al_2O_3) or non-catalyst (river sands) were at lower stage. The temperature of lower stage was kept at 923K, and the upper stage was raised from room temperature to 1123K at 10K/min. The producing gases throwing impinger were sampled and analyzed with GC. The yield of the total gas including hydrogen producing from the feces was remarkable increased by our catalytic-gasification method.

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This paper describe optimization of blending ratio for wood waste in co-combustion with coal by a large scale pulverized coal fired power plant. Grindability of wood waste have measured by simple test using a lab-scale cutter mill. Variation of plant efficiency with blending ratio is calculated by process simulator that incorporated an empirical equation to estimate mill power consumption of wood waste. The plant efficiency is decreased with increasing blending ratio of wood waste.

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To reduce environmental impacts, we have developed food waste gasification process to produce hydrogen and found that behavior and transformation of tars produced from food wastes are important. In this study we focused on the tar capturing and reforming when using γ-alumina particles as a sorbent and/or a catalyst. Based on our results, the γ-alumina particles were effective to produced hydrogen even under the pyrolysis conditions, which was increased with the temperature in the range of 400 to 800℃. Furthermore, the yield of hydrogen in the steam conditions was increased. It was found that the sorbent is available for tar capturing and reforming into hydrogen production.

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