Taiheiyo Coal Research Articles

1.太平洋炭のメタノール吸着特性(2)

1.太平洋炭のメタノール吸着特性(2)

44.太平洋炭の液化反応における水酸化銅の触媒効果(2) : 液化生成物の分子量分布

44.太平洋炭の液化反応における水酸化銅の触媒効果(2) : 液化生成物の分子量分布

43.太平洋炭の液化反応における水酸化銅の触媒効果(1) : 液化率に与える水酸化銅とその関連化合物の触媒効果

43.太平洋炭の液化反応における水酸化銅の触媒効果(1) : 液化率に与える水酸化銅とその関連化合物の触媒効果

Combustibility of biochar injected into the raceway of a blast furnace

The combustibility of Taiheiyo coal and oak char in the tuyere and raceway of an ironmaking blast furnace was simulated. The effects of injection rate, O2 concentration and particle diameter on combustibility were studied. Numerical results showed that increasing the O2 concentration from 23 to 27wt.% resulted in higher combustibility of both solid fuels. However, this effect was insufficient to increase the combustibility of oak char at high injection rates because its volatile content was lower than that of Taiheiyo coal. Temperature and reaction fields were sensitive to both combustion heat and volatile content. A longer raceway or smaller particle size was required to obtain the same combustibility of biochar as of the reference coal. If Taiheiyo coal with a particle diameter of 70μm was used at a high injection rate of 200 [(kgsolid fuel)/(1000Nm3feed gas)] with hot blasts containing 27wt.% O2, the particle diameter of oak char was required to be 60μm to obtain the same combustibility. These predictions reveal the potential of pulverized biochar injection instead of conventional pulverized coal injection in blast furnace ironmaking.

Geological Exploration and Offshore Drilling at the Taiheiyo Coal Mine

Geological Exploration and Offshore Drilling at the Taiheiyo Coal Mine

Kinetic study on solvent swelling of coal particles

AbstractSolvent swelling experiments of coal particles of Taiheiyo and Witbank coals in pyridine at 15–50°C were conducted by using an orthogonal microscope coupled with an image analysis system and the newly prepared temperature-controlled cell. Two kinetic parameters, n (a number that crudely indicates the nature of the solvent diffusion) and k (a rate constant), were calculated based on time profile of volumetric swelling ratio. The authors examined the correlation between these parameters and volumetric swelling ratios, to find that there was linear correlation between n and ln(1/k). By using the proportional constant, the authors calculated activation energy of the swelling of both coals. The energy changed with respect to each particle. Average values were 71kJ/mol for Taiheiyo coal and 55kJ/mol for Witbank coal, these values agree well with the values reported in the literature. The authors also examined the effects of pretreatments of both coals. O-Acetylation and pyridine pre-extraction lead to decrease the energies drastically.

Analyses of mild hydrogenation products of coals treated with zinc and butyl iodide

Butylation using zinc and butyl iodide under mild conditions (130 °C and atmospheric pressure) is an effective method to convert solid coals to soluble products in poor solvents such as hexane and benzene. Because of mild conditions and high solubility, the butylation of coals is found to be applicable for estimating coal structures. Until now, two typical coals, Taiheiyo and Yubari coals, were converted to hexane soluble products significantly. However they were too heavy to obtain much information on the structure of the original coals. In order to analyze the structural features of the coals butylated with zinc and butyl iodide, the polar mixture (PM) fractions separated from hexane soluble products (HS) from butylated Yubari and Taiheiyo coals were hydrogenated using Adkins catalyst. The HS products of hydrogenated PM fractions were fractionated by gel permeation chromatography (GPC), and the GPC fractions were further analyzed. After hydrogenation, structural parameters of HS products separated from PM fractions did not change so much, but molecular weight decreased. The GPC fractions (Fr.1–Fr.7) from both coals had similar high σal (degree of aliphatic chain substitution) as well as low fa (aromaticity) to the original PM fractions. These results indicated that the GPC fractions were highly butylated. Many structural parameters of GPC fractions except for Fr.7 were similar with each other. For Taiheiyo coal, the ring sizes of GPC fractions were 1–2, and similar to those from pyridine soluble products. For Yubari coal they were 2–3, and smaller than those from pyridine soluble product, 4 due to reductive butylation. The ring sizes of the Fr.7 from both coals were as small as one. Because the solvent soluble products were subject to reductive butylation, the naphthenic rings of the fractions seemed to be ruptured by hydrogenation. These findings suggest that high hexane extractability of the coals butylated with zinc and butyl iodide was caused by reductive butylation.

石炭資源の開発・利用に係わる環境技術と安全のアジアネットワーク 釧路コールマインとアジア産炭国における技術および人材交流

Kushiro Coal Mine Co., Ltd. was established in December 2001 by the support of local financial circles, local governments including Kushiro-city and Hokkaido government, just after of the closure of Taiheiyo Coal Mine which had the history of approximately 80 years. The shallow part of mining area and mining machineries were transferred from Taiheiyo Coal Mine, Kushiro Coal Mine has operated in the sea level of -300m coal fields under the seabed.The main business of Kushiro Coal Mine Co., Ltd. is coal mining business, international co-operation business (mainly the training project on coal mining technology) and environmental new business development.This report mainly shows the results of technical and human exchanges between Kushiro Coal Mine and Asian coal producing countries supported by METI, NEDO and JCOAL.

Characteristics of Hydrogen Production from Coal Tar with Subcritical Steam

A laboratory-scale batch reactor was used to perform a limited number of experiments on the steam gasification of coal tar formed by pyrolyzing Taiheiyo coal at 873 K for 2 h in N2. The study was intended to support the HyPr-RING process in which coal is gasified with steam in a fluidized bed containing Ca-based CO2 sorbent. H2 is the desired product, while substantial amounts of CH4 and small amounts of C2H6 were also produced. The amounts were decreased but the molar ratio of CH4 to H2 in the product gases was increased with a decrease of the temperature. The predominant production occurs in the initial stage including the heating period. The behavior for tar is similar to that for coal, suggesting that CH4 and H2 production from coal should be caused by tar produced from coal in the initial stage and especially that H2 production in the second stage should be by char from coal.

Localized Interaction between Coal-Included Minerals and Ca-Based CO2 Sorbents during the High-Pressure Steam Coal Gasification (HyPr−RING) Process

Pulverized Japanese bituminous coal (Taiheiyo coal) samples with diameter ranges of 38−75 μm and 180−250 μm were gasified with high-pressure steam in the presence of Ca-based CO2 sorbents. The experiments were carried out at 873 and 973 K and at holding times ranging from 0 to 120 min using a laboratory-scale fixed-bed reactor, and the solid−solid reaction between the Ca-based sorbents and the coal-included minerals during the steam gasification was investigated. Local scanning electron microscopy−energy-dispersive X-ray analysis of the solid residues obtained under different conditions showed that some constituents of the coal-included minerals, such as Si and Al, were contained in the sorbent particles. The solid−solid interaction between the Ca-based sorbents and coal-included minerals became significant at the higher temperature and at longer holding periods. This interaction will locally decrease the CO2 sorption ability of the sorbents. However, when a holding time of less than 10 min was employed, ...

Fundamental studies on hydrogasification of Taiheiyo coal

Rapid hydrogasification of a Japanese Taiheiyo coal was performed in a specially developed laboratory scale batch type reactor under conditions similar to an industrial gasifier to obtain fundamental data and a comprehensive understanding of the process. The experiments were carried out at 1073 K, 7.1 MPa atmosphere, with varying reaction times from 1 to 80 s and H 2/coal ratio in the range of 0.05–0.30 g/g. It was found that coal conversion was promoted at a higher H 2/coal ratio. The amount of methane was seen to increase with reaction time, whereas most of the other products showed dynamic characteristics with maximum formation during the observed reaction time. A comparison with results of pyrolysis in helium indicated that hydrogasification is mainly composed of two steps, initial primary pyrolysis followed by secondary gas phase reactions, including hydrocracking of intermediate hydrocarbons and methanation of carbon oxides.

04/00729 Influence of granular carbons on pitch properties: Méndez, A. et al. Fuel, 2003, 82, (10), 1241–1250

To evaluate the hydrogen donating ability of solvent for coal liquefaction, the liquefactions of Taiheiyo coal (Japanese subbituminous coal) and Yallourn coal (Australian brown coal) have been carried out in a 500 ml autoclave at 430–450°C under high pressure of hydrogen or nitrogen using a red mud—sulfur catalyst in the presence of different kinds of hydrogen donor solvents such as tetralin, decalin, methyl substituted tetralins and naphthalenes, etc.Liquefactions of Taiheiyo coal and Yallourn coal using hydrogen donor solvents such as tetralin or methyl substituted tetralins showed higher conversion and yield of SRC than that obtained using decalin. On the other hand, to estimate the effect of the hydrogen donor solvent, ab initio SCF molecular orbital calculation for several solvent molecules, such as tetralin, decalin, naphthalene and their methyl substituted homologues, has been applied. Calculated reactivity indices, for example, frontier electron density of hydrogen atoms in the solvent molecule and atomic orbital bond population of CH bond, were discussed and compared with the experimental results.

Rare earth element distribution in the acetic acid soluble fraction of combusted coals: Its implication as a proxy for the original coal-forming plants

The precise concentrations of rare earth elements (REEs) in Japanese Ashibetsu and Taiheiyo coals, in Indonesian Ambalut coal, and in Australian boghead coal have been determined, in order to compare the REE contents of the coals with those of plants and also to obtain further knowledge of the original plants from which these coals were formed. By leaching the coals after ashing using a 10% acetic acid solution, each coal sample was separated into two fractions: an acetic acid soluble fraction, and an acetic acid insoluble fraction. Our results show that three different types of chondrite-normalized REE patterns are observed in the acetic acid soluble fraction of these coals. The acetic acid soluble fractions of the Ashibetsu, the Taiheiyo, and some of the Ambalut coals showed REE patterns identical to those of peat vegetation. Those of other Ambalut coals showed an REE pattern that was similar to that of tree trunks. The boghead coal showed a different REE pattern that was similar to algae, an origin that is also suggested from a maceral study. The REE patterns of the acetic acid soluble fraction can therefore be a useful proxy for determining the original plants that formed the coals.

Continuous experiment regarding hydrogen production by coal/CaO reaction with steam (I) gas products

Coal/CaO powder mixtures were continuously supplied into a reactor to react with steam at high pressure and high temperature. At 923 K and 5.0 MPa, the gas produced from the reaction of Taiheiyo coal/CaO with steam consisted of mainly H 2, with smaller amounts of CH 4, C 2H 4, C 2H 6 and CO 2. Increasing the pressure enhanced H 2 production and CH 4 decomposition. Above 3 MPa, the gas from the reaction contained <3% CO and CO 2. Under high pressure, CaO reacted with steam to form Ca(OH) 2 which absorbed CO 2. The H 2/CH 4 ratio in the product gases from three different rank coals (Datong coal (bituminous), Taiheiyo coal (sub-bituminous), Wyoming coal (lignite) followed the order Datong>Taiheiyo>Wyoming. The Wyoming and Datong coals produced less H 2 than the Taiheiyo coal.

Coal gasification with a subcritical steam in the presence of a CO 2 sorbent: products and conversion under transient heating

Pulverized Taiheiyo coal (Japanese subbituminous coal) was gasified with steam in the presence of CO 2 sorbent (Ca(OH) 2) under relatively high pressure (approximately 20 MPa; subcritical condition) using a tubing-bomb microreactor (TB reactor). The transient characteristics in the conversion of coal and the formation of gaseous products during the gasification were investigated. During initial heating period, 40–50 wt.% of the coal initially loaded was rapidly converted to gas or tar. In the presence of Ca(OH) 2, the yield of gaseous products was apparently increased owing to the catalytic effects of Ca(OH) 2 on coal gasification. No CO 2 was observed in the produced gas at any soaking time in the gasification with Ca(OH) 2, suggesting that CO 2 sorption by Ca(OH) 2 took place effectively under high-pressure conditions. A rigid agglomeration of char and CO 2 sorbent was observed at relatively high temperature, which is attributed to the formation of melts of the CO 2 sorbent.

Investigation on rapid pyrolysis of Taiheiyo coal

Investigation on rapid pyrolysis of Taiheiyo coal

XRD evaluation of KOH activation process and influence of coal rank

Three Japanese coals with different rank (Ohmine, Miike and Taiheiyo coals) were activated with KOH from 300 to 850 °C. Higher rank coal with lower oxygen content showed a high yield and also a large specific surface area determined by N 2 adsorption isotherms. X-ray diffraction (XRD) patterns of the activated carbons were measured to characterize stacking structure of aromatic layers by standardized analysis of coal by XRD method, considering the presence of slit-shaped micropores among the stacking structure. Structural parameters obtained by this method were related to the yield and the surface area in order to discuss the feature of micropores developed during the activation.

Extraction of Taiheiyo coal with supercritical water–phenol mixtures

Taiheiyo Japanese sub-bituminous coal was extracted with supercritical water (SCW) and phenol mixtures at 673 K and at over fluid densities ranging from 0 to 0.5 g/cm 3. The extraction yield with SCW was 0.55–0.60, but increased with increasing the ratio of phenol to water, showing a maximum of 0.7 at water–phenol ratio of 4.5:0.5 and then decreased to 0.50–0.55 for pure phenol. The main products for the SCW–phenol extraction were bisphenol alkyl compounds, while these compounds could not be detected when SCW was used as the solvent. For elucidating the mechanism of SCW–phenol extractions, reactions between phenol and model compounds of hydrolysis products (formaldehyde, acetone, propionic acid, and 2-propanol) were conducted. In SCW, formaldehyde reacted with phenol to produce polymers, while neither acetone nor propionic acid reacted with phenol. The 2-propanol dehydrated to form propene, which reacted with phenol to form 2-isopropylphenol. The reaction rate increased with increasing water density. In SCW–phenol extraction of coal, phenol seems to inhibit reactions that lead to hydrolysis products or those that might cross-link to form the macromolecules. Phenol can be used with SCW to reduce retrograde reactions in residual coals.

Investigation on initial stage of rapid pyrolysis at high pressure using Taiheiyo coal in dense phase

Rapid pyrolysis of Taiheiyo coal was investigated with a laboratory-scale batch type reactor (BTR), which was specially developed to study various gasification processes at the conditions close to an industrial entrained bed gasifier. The experiments were carried out in helium at 1073 K, 7.1 MPa, varying reaction times from 1 to 80 s and coal/gas ratios in the range of 0.41–1.65 g/l. Extents of pyrolysis and profiles of product formation were discussed based on the results of char yield, gas and tar formation characteristics. It was observed that reaction of pyrolysis was significantly affected by coal/gas ratio. At high coal/gas ratios, pyrolysis was found to be retarded at initial stage. Pyrolysis products can be roughly divided into two groups. One is the ultimate products such as methane, carbon oxides, hydrogen, and benzene and the other is the intermediate products such as ethylene and toluene. Heat supply inside BTR was examined and the influence of thermal properties of atmospheric gases was investigated by carrying out pyrolysis in nitrogen and by comparing the results with that in helium. As a result, the heat capacity of atmospheric gas has less influence on pyrolysis process whereas heat conductivity of atmospheric gas as well as mixing conditions of gas and coal sample significantly affect the pyrolysis reaction.

自走支保切羽における天盤沈下波の発生

Roof lowering wave phenomenon was first observed by O. Jacobi, German researcher at longwall faces where mechanized powered supports were introduced in West Germany. Since Kushiro Colliery, Taiheiyo Coal Mining Co Ltd.,was going to introduce fully mechanized longwall mining system to their Numajiri area, it was essential to scrutinize this phenomenon, because if wave should have happened at the face, full collapse of the supports, particullarly at the rear leg position by reciprocating roof lowering is likely to occur.The author therefore carried out series of measurement at single prop and powered support faces, and introduced the results of measurement for basic design of the UU shaped frame type 12-leg powered supports.