High pressure differential thermal analysis was applied to the studies of lipuefaction of coal with carbon monoxide and water. Nine saamples of coal with different oxygen content were selected. Analyses of produced gas, separation of products by organic solvents and measurements of oxygen content were subsequently carried out. On the basis of these experimental results, the following conclusions were obtained.
(1) In the course of the coal liquefaction reaction, organic water solubles such as alcohol and carbonic acid were produced by the interaction of hydrogen and carbon monoxide which was first produced by shift reaction.
(2) According to the high pressure differential thermal analysis, it became clear that coal liquefaction reaction proceeded readily with the increase of oxygen content of samples and this agreed well with the results of the conversion.
(3) In the case of samples with an oxygen content over 20%, it was ascertained that coal liquefaction reaction with carbon monoxide and water proceeded more readily than liquefaction with hydrogen.
(4) In addition to these desults, it was noted that the amount of water after the reaction was less than the initial amount and a larger amount carbon dioxide was seen as compared with that of hydrogen was evolved. In addition the oxygen content of the reaction products were remarkably less than that of the original samples.
(5) On the basis of these results, with regard to the reaction mechanism for coal liquefaction with carbon monoxide and water, it may be surmized that initially hydrogen evolved by shift reaction made a high concentrated or selective attack on oxygen bonds as compared against high pressure hydrogen and as a result the liquefaction and deoxidation reaction proceeded smoothly.

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Yubari Coal were subjected to mild reaction conditions, and afollow up on the changes in structural parameter of the reaction products in the course of reaction was carried out as part of the investigation on the reaction mechanism of bydrogenolysis. At the same time two or three discussions were made on the chemical structure of coal,
(1) Original coal samples, Py-2, Py-1 showed highly similar structural charac-teristics and it was surmized that the decrease the molecular weight of the original coal to Py-1 could be mainly attributed to cleavage of the linkagebetween structural units accompanying deoxigene.
(2) It was shrmized that Py-1 as compared with A has a larger number of pericondensd rings. Further in the course from py-1→A it may be surmized fhat the production of side chains arizing from saturation of terminal aromatic rings is accompanied by cleavage of the linkage of structural units.
(3) From A→O₂ while saturation of aromatis rings is proceeding, the decomposition of structural units is limited and the main reaction of pecrease the molecular weight is the cleavage of linkage of the structural units. It was also clarified that the decomposition of structural units was remarkable at the O₂→O₁ stage.
(4) As pointed out hitherto it was reconfirmed that among Yubari coals there are two types oxygen. Namely one in which the oxygen reactivity is repidly removed and the other in which the removal is compalatively slow.
(5) Similar to the case of oxygen, there are also 2 types of sulfur. And it was recognized that inactive parts are removed only after the decomposition of structural units. It was also noted that nitogen exhibited a similar behavior to that of inactive sulfur.

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Classification and determination of various oxygen containing groups in high pressure coal hydrogenolysis products was attempted. First the total OH group was trimethylsilylated and the silica in the produced trimethyl sikyl ether was determined by atomic absorption anakysis and at the sametime R-NH2 which undergoes silylation was measured and corrected. Next, using a different method the phenolic hydroxyl group was measured. Based on the above data, it became possible to divide the oxygen in the samples into ether type, phenolic hydroxyl type and alchohoholic hydroxyl type which were measured accordingly.
Further the changes accompanying the course of hydrogenolysis of these oxygen containing structures were followed, and we arrived at the opinion that the phenolic hydroxyl group is produced by dissociation of ether type oxygen accompanying decrease the molecular weight arising from hydrogenolysis. Further, it was recognized that the hydroxyl group were removed along with the reaction course.

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Coal was decomposed thermally in pressurized nitrogen and hydrogen atmosphere to examine the effect of hydrogen on the decomposition. The thermal decomposition of coal was measured by thermogravimetry from room temperature to 900°C under the pressure of 1, 25 and 70 atm.
To obtain more detailed information products of the decomposition at 600°C under the pressure between 1 and 125 atm. were examined. The yield of the carbonization products was determined from their weight. The moleculer weight of the produced tar was measured by the method of melting point depression and the amount of the low boiling material of the tar was analysed by gaschromatography. Gas analysis was also applied on the produced gas.
In the thermogravimetry, it was shown that hydrogen had the effect above 500°C, and that the increase of volatile substance at 600°C was 10-15%. From the measurement of the yield and the analysis of the decomposition products, it was also shown that the yield of coke reduced and that of tar and gas increased, and the amount of methane in the produced gas increased remarkablly, in addition, the lower moleculer substances increased remarkablly, in addition, the lower moleculer substances increased in the produced tar.
From these results, the possibility of pressurized hydrogasfication of coal was suggested.

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Asphaltene, an intermediate product in coal hydrogenation, was prepared from 5 Hokkaido coals of different ranks, and the characteristics of each chemical structure was studied to clarify the basic characteristics as raw chemical material. According to the analytical results of its chemical structure, the difference in the chemical structure of asphaltene from the different coals. and correlation of the chemical structure of asphaltene, oil (S₁) and oil (S₂) were discussed. The results are summarized as follows:
(1) Asphaltene prepared from different coals have a comparatively similar eleme-ntary composition. However, it was considered that the aromatic ring structure of asphaltenes inherited the characteristic chemical etructures of each raw coal. It was also recgnized that the characteristics of chemical structure of asphaltene prepared from the same raw coal changed with the reaction condition.
(2) The yields of Hokkaido coal asphaltene are from ca. 20% to 40-50%, and show a general increase with the carbon content of raw coal. However, it was noted Taiheiyo coal asphaltene shows a singularity in its yield, molecular weight distribution.
(3) It was clarified that the molecular weight, average degree of poymerization and molecular weight distribution of oil (S₂) passing through asphaltene as an intermediate product were different from those of asphaltene, but the aromatic ring structure of oil (S₂) and asphaltene was similar. Moreover the chemical structure of oil (S₁) formed directly from coal is considerably different from that of asphaltene and oil (S₂). These facts indicate that the coal hydrogenation mechanism of formula (1) proposed on the basis of the reaction kinetic study is further supported by elucidating the characteristics of the chemical structucture of each corresponding product in formula (1), and in turn it became possible to give a further explanation of the experimental results.

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The chemical structure of four pitches is discussed. Each pitch was separated into nine fractions by solvent fractionation at room temperature with pyridine, quinoline and a series of binary solvents consisting of n-hexane and benzene.
The average structure of the fractions obtained was estimated by elementary analysis, MW, GPC, IR, UV and NMR.
Results of the characterisations of four pitches are as follows:
(1) Coal tar pitch, (i) Coal tar pitch contains about 25% of the quinoline soluble and insoluble fractions. It is suggested that this pitch contains a much condensed aromatic ring system from these fractions.(ii) Fractions from n-hexane soluble to pyridine soluble have the largest aromaticity and lowest H/C ratio compared with the corresponding fractions of the other pitches.(iii) On the basis of the parameter Cp/Ca (or Hau/Ca), the average structural unit of each fraction tends to increase in the number of the aromatic rings with increasing fraction number, from 3-4 to 8-9 rings. Moreover, it was suggested from the parameters σ and Ln, that about 10% of the peripheral carbon atoms in the aromatic sheet are replaced by methyl groups.(iv) The average molecule of the fractions appears to consist of less than two average structural units, particularly, the aromatic rings in the average molecule for Fr. 1 to Fr. 4 seem to have nearly equal numbers of average structural units.
(2) Naphtha cracking tar pitch; (i) Fractions of this pitch have the largest average molecular weight and lowest H/C ratio of all pitches studied. It is suggested that naphtha cracking tar pitch contains fairly aliphatic structures.(ii) The average structural units of each fraction contain from 3 to 8 rings varying with descending order of the fraction and consisting of condensed aromatic systems. It was suggested from a and Ln that about 20-30% of peripheral carbon atoms in the average structural unit are replaced by ethyl groups.(iii) The average molecule of the fractions appears to consist of condensed aromatic ring systems with 2-3 average structural units for Fr. 1 Fr. 5 and more than 4 average structural units for Fr. 6 and Fr. 7.
(3) Catalytic cracking tar pitch of crude oil; The characteristics of this pitch appear to resemble coal tar pitch. However, the H/C ratio and molecular weight were slightly larger than coal tar pitch.
(4) Prepared pitch from polymerized naphthalene; This pitch is different from the other pitches described above. The structure of fractions of this pitch appears to consist of a mixture, with more than three units of naphthalene bonded at the 2-and 6-positions of the naphthalene nucleus and perylene type products. Moreover, these products appear to contain some aliphatic structures.

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Fundamental studies on the separation of coal derivatives by means of gel permeation chromatography (GPC) are reported on (1) the chromatographic conditions for preparative GPC separation for structural analyses of coal and (2) basic experiments to odtain the molecular weight distributtion from analytical GPC elution curves using the chloroform soluble qart (γ-part) of pyridine extract from Akabira coal. On the basis of this informaton, the distributions of molecularweight of oil and asphaltene obtained from hydrogenolysis of Akabira coal are investigated by GPC analyses and their variation with reaction temperature is discussed.
The petroleum soluble portion (γ₁-part) and the insoluble portion (γ_2-4-part) from the γ-part were selected as the sample for the discussion of the optimum conditions for GPC separation, such as pore size of gel and elution solvent. From the experimental results, it is obvious that separation by preparative GPC is achieved, odtaining fractions of considerably narrow molecular weight distribution. This contributed remarkably to the resolution of thechemical structure of coal. The relationship detween the elution volume (Ve) of the analytical GPC and average molecular weight (M) estimated by vapor pressure osmometry is fairly good for the fractionation products from preparative GPC (Fig. 9, 10). The M-Ve correlation lines of the ₁- and the _2-4-parts were straight lines of different slope. Therefore it was assumed that the difference was due to a difference in structural type on the components. Consequently, these γ relationships of log M-Ve can be applied to the estimation of the molecular weight distribution from analytical GPC chromatograms as the correlation lines of high-molecular and low-molecular weight components respectively for the coal derived liquids.
Oil and asphaltene in hydrogenolysis products werealso separated into fraction on the basis of molecular weight by preparative GPC and each fraction was correlated by elution counts of analytical GPC and average molecular weight. The results of these relationships were in fairly good agreement with correlation lines of log M-Ve odtained from the γ₁ and the γ_2-4 componets respectively (Fig. 13, 14). From the elution curves of analytical GPC for oil and asphaltene of varying reaction temperature, it is recognized that the distribution of molecular wight for asphaltene shifts gradually in the direction of a lower molecular weight distribution as the reaction temperature increases. On the other hand, the distribution of moleclar weight of oil changes only slightly and tends to converge to the constant distribution of low molecular weight components.

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At the early stage of carbonization of coal-tar pitch, a lot of small anisotropic sphere has been occured. According to rise of heating temperature, they have grown to 20-30μ in diameteer, combined then with each others, begun to flow, and finally solidified forming manifold coks-structures. It is therefore, considered that behavior of sphere must decisively influence on coks structure obtained.
To advance the present knowledges about behavior of sphere, morever, following examinations are carried out;
Optical character of this sphere reinvestigated under the transmitted-reflected microscope, using polished thin section of sphere isolated by quinoline.
For getting new information about physical structure of sphere, spherules etched by heated quinoline are investigated under micro-interference microscope.
Coks-structures are also examined under the scanning microscoppe.

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In order to investigate behaviour of coal in petroleum vacuum residue, mixture of two parts of Khafji residue and a part of coal was heat-treated at temperature range of 400-450°C for 60 min. Pitch produced was fractionated by benzene and quinoline, and was observed by using a polarized-light microscope.
The results obtained were as follows,
1) From change of amounts of the quinoline soluble matter with heat-treatment temperature (HTT), it could not be recognized that coal in petroleum vacuum residue disintegrated itself into the quinoline soluble matter.
2) In the case of Miike and Takamatsu coal, coal particles in the pitch were covered with mesophase spherules formed in petroleum vacuum residue. In the case of Miike and Nishikawachi coal showing optically anisotropic structure under heat treatment, anisotropic parts in coal particles and in petroleum vacuum residue were indistinguishable clearly in the pitch heat-treated at 450°C.

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The decomposed gases of phenol-formaldehyde retin (1), 3-methyl-phenol-formaldehyde resin (2) and 3, 5-dimethyl-formaldehyde resin (3) with a brown coal (Tempoku coal), during their heat treatment up to 1, 600°C, were analysed gaschromatographically.(1) has a maximum of production rate at 720°C for hydrogen, 600°C for methane and carbon monoxide, and 520°C for water.
As a number of methyl groups of resins increases, the maximum point of methane production shifts to the lower temperature side and its quantity also increases. Similar phenomenon is seen in the case of water. Hydrogen and carbon monoxide do not change their maximum production temperature for all resins, but their quantity reduces with the increase of methyl groupes.
A mechanism of carbonization reaction was proposed on a ground of chain reaction.
Brown coal shows similar phenomena except relatively large quantity of carbon dioxide, and two maxima of carbon monoxide. The basical decomposition reaction and its structure may be similae as that of phenol resins, especially as (1). The activationenergy of each gases were calculated and they gave nearly same values for the same kind of gases, namely 22.9 and 34.8kcal/mol for methane, 7.3, 17.4 and 36.6 kcal/mol for H₂O, 13.7 and 36.6 kcal/mol for carbon monoxide, and 32.9 kcal/mol for hydrogen.

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Maney students proposed to evaluate coking coals by the petro. graphical method and recognized in principle the utilities for coking industries, but the method, which as yet beeingmeasurerd manualy seemed to be difficult to apply for this purpose, since it meeds too much time and labor.
We attempted and suceeded to develope an automatic reflectivity classifying and recording equipment in order to use it for plant blend controll as well as in research investigations.
This new equipment enables the accurate measurement of mean reflectance of Vitrinit and distinguishes the main maceral components to be made more rapidly using a mechanical microscope stage and the automatic electronic classifying and recording equipment, which connectes directly to a Computer and produces the results in histogram form for discfilo read out, C. R. T.(Cathod Roy Tube) or typewriter.

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