The author was engaged in research works on coal and coke, at the Technical Research Institute of Yawata Works, from the entrance into Nippon Steel Corporation after university graduation until the retirement (1938-1968).
In this paper the author summarizes the development and problems of studies on coal and coke, describing author's main thoughts and anecdotal stories about the researches, especially in detail about the coking properties of coal.

抄録全体を表示

Distillates of a coal-derived liquid have been separated into compound classes by HPLC. High-voltage GC/MS and low-voltage GC/MS technique have been employed to analyse the individual components and the hydroaromatic group type concentrations in the HPLC fractions.
The result of the analyses shows that the coal-derived solvent contains hydrogen donor compound types (e.g., tetralin, hexahydroacenaphthylene, hydropyrene) and nonhydrogen-donor compound types (e. g., fluorene, acenaphthene, dibenzofuran).
The proton donatable quality index (PDQI) has been calculated from the data of donatable naphthenic hydrogen contents in hydroaromatic species analysed by HPLC and GC/MS method. The PDQI values suggest that the monoaromatic compound class has high hydrogen donatability and the other compound class'es have low hydrogen donatability.
The tendency obtained from HPLC and GC/MS method was in good agreement with that of the naphthenic hydrogen contents estimated by ¹H-nmr spectral method.

抄録全体を表示

Six coals including brown coals and subbituminous coals were hydro-genated with solvent of tetralin and without catalyst, at 450°C of temperature and under 200kg/cm² of hydrogen pressure. The middle distillate fraction of b. p.from 180 to 415°C obtained from coal liquid was analysed by gas chromatograph equipped with fused-silica capillary column. GC-MS and standard reagents obtained by alkylation of poly-condensed aromatics were also used to assign the chromatogram.
The analytical system consists of Hewlett-Packard 5880 gas chromatograph with a SP-2100 capillary column (50mm×0.2mm) and a Hewlett-Packard 5992 mass spectro-meter. The middle distillate was separated and analysed at one time according to the three step-temperature raising program (35°, 25min; 5°/min; 100°, 5min; 3°/min; 150°, 3min; 2.5°/min; 260°, 50min).
About 1/2 of middle distillate without tetralin and naphthalene were straight paraffins and naphthalenes with methyl groups were the secondary main product. Very small amount of poly-condenced aromatic compounds such as acenaphthene, fluorene, phenanthrene, pyrene and fluoranthene, they are main components of coal tar, were found and many types of methylated compounds of these aromatics were assigned in the distillate produced from coal.

抄録全体を表示

The bulk density of needle coke, which has been recognized as the essential filler of the electrode for the steel industry is expected as high as possible in addition to the needle-like anisotropy better performance. The effects of preheat-treatment on the bulk density of semi-cokes produced from A240, (petroleum pitch), CTP-ASM (QI free coal tar pitch) SHAS (Sumatra heavy asphalt) and S-oil (residue from FCC process) were examined in the present study.
The bulk density of the semi-coke produced from A240 without preheat-treatment was as low as 0.21g/cm³, very thin pore walls with many pores being observable in semi-coke. The preheat-treatment for more than 36h at 450° without refluxing markedly increased the bulk density up to 0.80g/cm³, although a preheat-treatment at a higher temperature of 480°C for 12h resulted in 0.40g/cm³. The pitch had solidified at the end of the heat-treatment. Refluxing treatment further increased the bulk density the treatment at 520°C, which was much higher than that of non-refluxing conditions, gave a bulk density up to 1.20g/cm³.
The bulk density of the semi-coke from CTP-ASM of high fa value increased from 0.30g/cm² (without preheat-treatment) to 1.20g/cm² after the preheat-treatment at 480°C for 6h under refluxing. SHAS of low fa value and high molecular weight, which produced flaky cokes without preheat-treatment, also provided a bulky coke afrer the preheat-treatment at 420°C, whereas the treatment at 480°C resulted in the flaky cokes since the carbonization leading to the solidification took already place during the treatment. The refluxing treatment against SHAS failed to increase the bulk density. Refluxing materials of SHAS may segregate the carbonizing material of high aromatisity as an anti-solvent resulting in the rapid increase of viscosity of the latter phase.
The preheat-treatment was also effective to increase the size of optical texture although the conditions of preheat-treatment to achieve the largest sizes of optical texture were not always same to those to obtain the highest bulk density.
The preheat-treatment conditions suitable to increase the bulk density appear very sensitive to the structure of starting materials. The key structural factors modified by the preheat-treatment were discussed in relation to the carbonization mech-anism, which may determine the bulk density and optical anisotropy of the semi-coke.

抄録全体を表示

In order to investigate the influence of pressure on caking property of coal, a high pressure Gieseler plastometer was produced and fluidity of Akabira coal was examined under various pressure of Ar atmosphere.
Characteristic form of fluidity curve of Akabira coal was essentially unchanged. Maximum fluidity was 1500DDPM at ambient atmosphere and it increased with pressure at first and reached to 45000DDPM at 10kg/cm²G. At higher pressures than 10kg/cm²G it decreased with pressure toward the point of 5000DDPM at 50kgjcm²G.
A softning and a maximum fluid temperature fell both slightly and a solidifica-tion temperature rose gradually by ca. 10° as pressure increased from 0 to 50kg/cm²G.
Change in fluidity curve after rapid pressurization from 0 to 10kg/cm²G was examined precisely as a function of the temperature of pressurization. Below 410°C the fluidity curve, obtained after the pressurization, followed the curve measured at 10kg/ cm²G, but above this temperature the former curve differd from the latter and the maximum fluidity in the former dropped with the temperature of rapid pressurization.
The fluidity measurement was also carried out under reduced pressures. Maximum fluidity decreased from 1500 to 30DDPM as pressure was lowered from 760 to 20 torr.

抄録全体を表示

Metallic oxides for dry-type simultaneous removal of SO_x and NO_x were investigated. This process is based on the principle that SO_x can be removed by the sulfation of CuO in metallic oxides, and NO_x removed by the catalytic reduction with NH₃ over CuSO₄ formed. Therefore, the most important point for the practical use of this process is to develop active metallic oxides, and a method to regenerate repeatedly CuSO₄ formed to CuO. Various metallic oxides were prepared by the coprecipitation from different compositions of CuSO₄, Al₂ (SO₄) 3, Si (OC2H5) 4, TiCl4 aq. etc. with NH₃ aq. The experiments were carried out using a flow type packed bed reactor for the reduction of NO_x or the removal of SO_x and NO_x, and a thermo-balance reactor for the basic study on the removal of SO_x under atmospheric pressure at 350°C . The inlet gas was 1000ppm S-500ppm NO-500, 667ppm NH₃-5% O₂-10% H₂O-N₂. The experiments on the regeneration conditions were carried out by the reduction with NH₃/H₂O mixture, and then the oxidation with O₂/H₂O mixture.
The results obtained are as follows:
1) 30 mol% CuO-20 mol% SiO₂-50 mol % TiO₂ was found as the most preferable metallic oxides for the simultaneous removal of SO_x and NO_x, in addition to 40 mol % CuO-20 mol% Al₂O3-40 mol% TiO₂ found previously.
2) The suitable regeneration conditions are to reduce from CuSO₄ to Cu₃N with 5-20% NH₃-1.5-7.4% H₂O-N₂ at 400°C, and then to oxidize from Cu3N to CuO with 5% O₂-0-10% H₂O-N₂ at 250 to 350°C.

抄録全体を表示

With regards to the effects of the bulk density in horizontal coke oven, to make-clear the mechanism of improving coke quality taking into consideration not only the pyrolysis gas flow but also the effective thermal conductivity of coal and-coke, the experiments were proceeded in the range of the bulk density from 0.65 to 1.04t/m₃. The small coke oven (20-35 kg oven) could provide the data of the gas pressure and the temperature of predetermined place in the charged coal or coke during its carbonization.
At the lower initial bulk density, considerable amounts of the evolved gases penetrate into the coal parts in low temperature and are condensed there. As a result, the pseudo plastic zone showing the highest gas pressure in a carbonizer is formed. This zone being in the lower temperature than the normal plastic zone, the gases flow in coke oven is divided with it into the two flow. One is to coal fines and the other to the heating wall. The higher bulk density make the higher permeability of coal fines, which bring about the less penetration of evolved gases to coal fines. Then the pseudo-plastic zone shift to the higher temperature part, and the effective thermal diffusibility of coal and coke become lower to make the heating rate slow. Therefore the some pyrolysis gases become to react with coal fines at the higher temperature and with the longer time, which promise the higher coke yield as well as the stronger bond between coal particles. It is concluded that the improvement of the matrix strength of coke due to the higher bulk density, is provided mainly with the following factors:
(1) the reduction of the porosity brought by making the distance between coal particles less.
(2) the higher coke yield and the stronger bond between particles based on the above mentioned mechanism.

抄録全体を表示

Liquefaction of four kinds of brown coal and two kinds of sub-bituminous coal was carried out to clarify the relation between the properties of the product oil and the sort of coal. Coal of 80g (maf) and tetralin solvent of 100g were put into a 500me stainless steel autoclave and were heated at 450°C under hydrogen pressure of 200kg/cm₂ without catalyst. The liquid product was separated into distil-late fraction (-415°C), oil fraction (undistillable and heptane-soluble), asphaltene fraction (heptane-insoluble and toluene-soluble) and preasphaltene fraction (toluene-insoluble and THF-soluble).
The yields and properties of each fraction were significantly depended on the coal. A substitute for distillation curve diagram was obtained from gas chromatographic analysis; the total amount of the effluent was plotted as a function of the carbon number of straight chain paraffins instesd of retention time. In case of the brown coal there were much lower boiling point fractions which were caused by the production of large quantities of alkyl naphthalenes. In case of the subbituminous coal on the contrary, there were rather higher fractions of like C₂₃-C₂₇ n-paraffins, corresponding to the boiling points of 400-450°C, which were caused mainly by the production of straight chain paraffins.
H/C value and contents of sulfur and nitrogen in a fraction depended upon the sort of coal, but the cause of the difference between the brown and subbituminous coals had not been clarified yet. As the fraction became ligher the H/C value grew higher. The difference in the sulfur contents during the fractions was small. The nitrogen content increased as the fraction became heavier.
The extent of dehydrogenation of tetralin solvent to naphthalene depended upon the sort of coal. When the solvent was dehydrogenated to higher extent, higher amount of THF-insoluble fraction was obtained.

抄録全体を表示

With the increased requirement for liquid fuel from coal in recent years, it has become very important to understand the nature and behavior of mineral matter in coal utilization.
In the present review, recent studies on the identification and quantification of mineral matter in coal such as pyrite, kaolinite etc. as well as the catalytic effects of inherent mineral matter on coal liquefaction and gasification have been surveyed.

抄録全体を表示