Wakamatsu Research Insti tute of J -POWER has been developing R&D activities of clean coal technology since 1980’s. We are currently developing oxygen-blown coal gasification technology using two-stage spiral -flow gasifier, named as EAGLE gasifier. We are also test ing to realize IGFC system using SOFC hybrid module, and researching Green Oil production from microalgae, towards a low carbon society.

An experimental study of Raman spectroscopy analysis of pulverized coal char was conducted to evaluate the reactivity of char in a pilot scale blowpipe. To investigate the progress degree of char oxidation, we prepared mildly oxidized char samples in addition to those sampled from the blowpipe. The surface crystallinities are different with particle diameters. This result suggests that the reaction histories of char largely depend on char trajectories in the blowpipe. The speculation that the large particle is exposed to higher temperature is consistent with the knowledges obtained from previous numerical simulation. Therefore, the Raman spectroscopy would become a useful tool to estimate the reaction histories of char in the blowpipe.

In our previous study, the gasification reactivities and characteristics of char prepared at various pyrolysis temperatures were investigated and it was found that catalytic effect induced by highly dispersed inherent iron in the sub-bituminous coal had much impact on the char gasification reactivity. We have been proposed the extended random pore model, which is composed of the sum of non-catalytic reaction model and catalytic reaction model. In this study, the catalytic effects of inherent iron were estimated by the application of the extended random pore model to TG profiles of CO₂ gasification and the correlation between the results of kinetics and analysis was investigated.

To increase sludge utilization for energy fuel, we proposed a carbonization process of sludge and coal. So, we conduced the co-carbonization experiment to clarify the material balance during co-carbonization of sludge and coal. And to clarify the reactivity of co-char produced from sludge and coal. In carbonization experiment, we used dried sludge and coal as sample, and coal ratio was changed. And thermogravimetric analysis was conducted to reveal gasification behavior of co-char. As a result, co-char yield increased, and tar yield and gas yield decreased by adding coal amount more. In co-char reactivity analysis, gasification rate of co-char was slow down when coal ratio increased.

Activated carbon was prepared from high ash Mozambican coal by chemical activation through K₂CO₃ impregnation and later tested for adsorption of heavy metals from aqueous solution. The effect of activation temperature, impregnation ratio on BET surface area, pore size and pore volume were discussed. It was observed that the activated carbon prepared at a reaction temperature of 800 °C and impregnation ratio of 1:1, showed larger specific surface area of 895 m²/g and pore volume of about 0.4 cm³/g. The capacity to remove zinc, and chromium from aqueous solution was tested by batch experiments carried out at room temperature in 100 mL Erlenmeyer flasks. The adsorption percentage of Zn was satisfactory, reaching about 97.8% at contact time of 1 hour while for Cr the percentage of adsorption was lower, attaining only 10.8% at the end of 1hour experiment.

Low rank coals are susceptible to spontaneous combustion based on low-temparature oxidation reaction. In order to prevent spontaneous heating, theoretical study on coal oxidation reaction has been studied. In this study to clarify the oxidation reaction pass and its energy level, the quantum chemistry calculation was conducted. With the calculation results, ¹H-NMR analysis, and TG analysis, the reasonable reaction pass, stable functional group sturcture, and its exothemic heating value were evaluated. Therefore, it was found that the propensity to spontaneous heating was decreased by being oxidized aliphatic hydrocarbon group and oxygen-containing functional group into stable ester group in advance.

Coal oxidation experiments of each coals were carried out under the condition of 60, 70, 80°C in humid atmosphere. CO₂ was the major product in each coals. Therefore, their oxidation reactivity were evaluated by CO₂ formation rates. Frequency factors and activation energies were calculated and prediction formulas of CO₂ formation rates were made. CO₂ formation rates caluculated by their equations showed that Coal A has higher oxidation reactivity than Coal B at acutual pile temperature range.

Spontaneous heating of sub-bituminous coal causes various troubles when handling it in thermal power plants. Therefore, it is important to establish a method for evaluating its self-heating character. In order to resolve this problem, we have developed an apparatus for determining the self-heating characteristics of coal - Coal Adiabatic Self Heating equipment (CASH). With this equipment, we have measured heating rates of several lots of sub-bituminous coal and compared with those of testing piles using the same lots. As the result of those experiments, we have found that the rate of the temperature increased measured by CASH showed similar patterns of variation of internal temperature in testing piles. With all those of results, we believe CASH measurement is a useful method to evaluate the self-heating character of sub-bituminous coal.

Coal blending effect on spontaneous combustibility was studied with laboratory scale test using Spontaneous Ignition Tester (SIT-2, Shimadzu Corporation) and field test using 150-ton simulated pile. Indonesian lignite and Indonesian bituminous coal were used as the sample. The laboratory scale test results showed that increase in blending ratio of bituminous coal leads to decrease in spontaneous combustibility. The field test results also supported the laboratory scale test results that coal blending is effective for suppressing spontaneous combustibility.

In a series of studies on development of an advanced desulfurization process of heavy hydrocarbon resources under mild conditions without pressurized hydrogen and catalyst, removal behavior of organic sulfur was investigated for a coal extract by using sulfur free imidazolium type ionic liquid. Sulfur removal progressed with increasing number of extraction step and 87% of sulfur removal was achieved after the fifth treatment. The coal extract could be recovered at high yields from the ionic liquid phase by back extraction with 1-methylnaphthalene.

Coal fly ash(CFA),which contains hazardous elements such as selenium and boron. These elements are easily leached out to water environment and contaminate the surface and groundwater. The leaching amount of these hazardous elements from CFAs exceeded the environmental standards of soil and landfill sometimes. In this study, effects of aging process on the leaching of hazardous elements from CFAs was examined. The leaching amount of selenium, boron, chromium and fluorine from CFAs decreased with the lapse of aging time. Selenium leaching from aged CFAs was influenced by the calcium content in original CFAs. The results of XRD analysis indicated selenium in aged CFAs was immobilized by hydrated minerals such as ettringite.

As a result of elution test on coal ash, elution beyond the soil environmental standard value was confirmed. So, it is important to develop a simple analytical method for development of suppression technology. In this study, analysis of fluorine content in coal and coal ash was carried out by simple and quick method of analysis using oxygen flask combustion method (OFC) from the conventional method. We analyzed content by OFC and fluoride ion electrode (FISE) using several coal certified substances. As a result, it was found that the recovery rate tends to be low for samples with high fluorine content and high ash content. It was considered that the mineral that the melting point and decomposition temperature contained in coal is high and the effect of the reaction promoter (WO 3, Sn) can not be obtained lowers the recovery rate.

Coal ash with a high degree of heavy metal elution was produced by a laboratory scale pulverized coal combustion furnace. As the volatile matter of coal increased, the elution volume also increased. The relationship between heat treatment conditions and elution was investigated. After the addition of heat of about 1150 °C or higher for 1 hour or more, the elution degree of the main eight heavy metals became lower than the detection limit. It was confirmed that elution did not re-occur even after a 12-month period and it was thus concluded that this treatment had long-term stability. It was also found that the loss on ignition (LOI) was reduced to the JIS specified range due to the heat treatment.

Mercury forms in fly ash and desulfurization gypsum produced from the coal-fired power plant were analyzed. A combination of temperature programmed desorption (TPD) and cold vapor atomic absorption spectrometry (CVAAS) was applied and the optimum operating condition was determined to clarify the forms of mercury. TPD curves of mercury obtained for the ash and gypsum were analyzed qualitatively and quantitatively with comparing to the peak temperature and linear combination of TPD curves of model mercury compounds. The results indicated that mercury in the desulfurization gypsum was mainly composed of HgCl2 and the adsorbed one by unburned carbon.

Catalytic conversion of biomass cellulose into C₃ and C₄ light hydrocarbons over Pt supported catalyst was investigated. Pt supported on sulfated mesoporous zirconia catalyst (Pt/MP-ZrO₂-SO₃H) showed the highest cellulose conversion among the tested Pt supported catalysts. A strong Brønsted acid site of MP-ZrO₂-SO₃H support is considered to contribute to the cellulose hydrolysis.

In this study, oxidative decomposition of bio-oil model compound (stilbene) was carried out using acetic acid, hydrogen peroxide and iron-supported zeolite catalyst (FeZSM - 5). In all cases, stilbenes were not detected after oxidation reaction. Main compound after oxidation of stilbene was benzoic acid. The amount of benzoic acid increased with increasing reaction time. When the stilbene was oxidized for 24 h under the presence of FeZSM-5(0.5) and 11.9 ml of hydrogen peroxide, the yield of benzoic acid reached a maximum.

Direct carbon fuel cells (DCFC) are fuel cells utilizing solid carbon as fuels. We proposed a novel DCFC system using tubular type cells which enables continuous supply of solid fuels. This study investigated basic characteristics of DCFC using tubular type cells. A tubular cell was inserted into the mixture of activated carbon and molten carbonate. Continuous power generation was achieved for 100 mA cm^-2 at 800°C. Most of CO₂ generated by anode reaction was presumed to react with carbon and changed to CO by Boudouard reaction. It is suggested that operation temperature for DCFC should be under 700°C to prevent carbon consumption by Boudouard reaction from the viewpoint of the fuel utilization ratio.

The objective of this study is to construct three dimensional aggregated structural model of bituminous coal to clarify the mechanism of relaxation of coal aggregation by heating. Our approach consists of a combination of experimental and simulational mehod. We obtained two dimensional average molecular structures of fractionation samples which were obtained by acetone, pyridine, and magic solvent (CS₂/NMP mix solvent) extraction of coal. Two types of three dimensional aggregated structures of each fraction were constructed by Molecular Dynamics (MD) simulation where the interactions among molecules are considered. Since the calculated T_g (glass transition temperature) calculated for the cubic-cell is closer to the experimental T_g than the one for the orthorhombic-cell, it is suggested that the former cell is more suitable for the prediction of three-dimensional coal structure.

One of the important purposes of the coke in the blast furnace is the spacer to ensure the gas and liquid permeability. In other hands, ash particles in coke became slags inside the furnace and these are one of the causes that significantly worsen the permeability. In this study, combustion and gasification experiments of coke were conducted at each experimental temperature. Ash particles in the coke samples were analyzed by using SEM in order to clarify effect of temperatures on ash particles characteristics during combustion and gasification of coke.

In cokemaking process, understanding on pore formation through melting behavior of coal is important to control coke pore structure and strength. However, in-situ observations of pore formation have never been achieved due to various difficulties. Instead, the pore formation has been estimated based on cross-section observation of quenched samples. In this work, synchrotron X-ray imaging was applied during a carbonization test to observe the pore formation in situ. The images of pores were successfully obtained every 0.4 degrees Celsius without quenching. This in-situ imaging technique potentially contributes to the clarification of coking process of coal and the improvement of techniques to control the coke quality.

In our previous study, ”permeation distance method” was developed for measuring unique coal thermoplasticity. It was revealed that high fluidity coal having longer permeation distance forms thinner pore-wall structures in coke and that coke strength deteriorated when coal blend included longer permeation distance coal. In this paper, influences of oxygen in coal and weathering processing on permeation distance and coke strength were investigated so as to clarify dominant factors of permeation distance and possibility of controlling permeation distance. As a result, when sample coals released more oxygen-containing gas during carbonization up to 550 °C, the measured permeation distance of the sample coals became shorter. Moreover, permeation distance and coke strength deterioration caused by long permeation distance coal was reduced by weathering processing. Consequently, it was cleared that oxygen was key factor determining permeation distance and coking properties especially of coal with long permeation distance.

Coal charged bulk density in coke oven is important for the production and quality of coke. In this study, we investigated the application of the space ratio estimation model for estimation of coal bulk density with different grinding particle size. We measured the bulk densities of coal with two types of particle size distribution, and also estimated that. The changes with different size distribution of bulk densities could be approximately estimated. Especially, in the case that the value of space ratio excludes the wall effect was used for estimation, the relationship between estimated value and measured value became better.

We considered the method for measuring the contraction of the active components and inertinite. The active components were carbonized as a bulk sample containing coal and semicoke, and the inertinite was used as only inertinite bulk. We obtained good results for the second contraction difference between active components and inertinite It was confirmed that the contraction of the active components were higher than that of the inertinite, and the contraction of the active components tended to be higher as the high rank coal.

Catalytic cracking of 3-ring polycylcic aromatic hydrocarbons (PAHs) with hydrogen donors (naphthenes and paraffins) was investigated using residue fluid catalytic cracking (RFCC) catalysts with high hydrogen transfer activity. 3-ring PAHs were partly hydrogenated by accepting hydrogen species released by hydrogen donors, and then converted to monocyclic aromatic hydrocarbons (MAHs) by consecutive cracking of the saturated rings. The rate-determining step of the 3-ring conversion was the cracking of the saturated rings. These results suggest that the hydrogen distribution among the reactants and products in RFCC process is important for optimizing the heavy oil processing.

For the coke production process, it is essential to increase the ratio of slightly caking coal usage by enhancing technical capabilities and to develop technologies for storing coal safely under appropriate management in order to expand slightly caking coal usage further. In this study batch-type reactor was used for a low-temperature oxidation test of coal in a closed system. The oxidation test was performed on coal at temperatures between 40°C and 80°C for a relatively short period of time (one to four days). The process of low-temperature coal oxidation consumes a markedly large amount of oxygen compared with the oxygen that is released in the form of CO and CO₂, and most of the oxygen released into the gas phase was probably captured by chemical adsorption.

We developed an apparatus for measuring the propensity of spontaneous self-heating of coals, which is based on the adiabatic moist coal spontaneous heating method (R₇₀) established by B.Beamish et al in 2000 and 2010, as selected through bibliographic surveys. The apparatus consists mainly of gas supply module, temperature control module, reaction module including reaction vessel and oxidant gas tube located in the oven. Through the repeated trial measurements of dry/moist coal samples including sub-bituminous coal prepared with vacuum dehydration, we reproduced the thermal profile of spontaneous heating of low-rank coal, which reflected the moisture content to form the plateau of temperature rising region.

Temperature increase of dried brown coal packed in a small tube reactor was measured in the gas stream of either wet air or dry air. The reactor was placed in a temperature controlled air circulating oven. In the wet air stream big temperature increase was observed even at 50 °C of oven temperature, whereas the temperature increase was very small in dry air even at 110 °C of oven temperature. The temperature changes of coal bed with time and position of the reactor were well simulated by simple one-dimensional energy and mass balance equations. Simulation in a wet air stream at 70 °C of oven temperature under adiabatic condition showed spontaneous heating of coal leading to combustion, showing that the spontaneous combustion is caused by simultaneous effects of water vapor adsorption and air oxidation.

For the coke production process, it is essential to increase the ratio of slightly caking coal usage by enhancing technical capabilities and to develop technologies for storing coal safely under appropriate management in order to expand slightly caking coal usage further. In this study batch-type reactor was used for a low-temperature oxidation test of coal by using isotope oxygen (¹⁸O₂). The oxidation test was performed on coal at temperatures between 40°C and 80°C for one day. We thereby showed that the amount of oxygen consumed at low temperatures of 60°C or lower was markedly larger than that of oxygen released as CO and CO₂, and that most of the carbon oxides produced in this process contained ¹⁶O.

We examined that the effects of moisture content on spontaneous heating of low-rank coal with temperature profile obtained by CASH (Coal Adiabatic Spontaneous Heating method). The changes of raising rate in each temperature region showed that the both acceleration and inhibition effects to spontaneous heating reaction. And we tried to reproduce the actual temperature profiles in measurements with numerical simulation model.

In recent years, sub-bituminous coal which has high spontaneous heating characteristics has been increasingly introduced into coal-fired power plants. As no official measurement methods have been established for coal's spontaneous heating characteristics, we investigated measurement methods that could be applied for the stored coal management. We measured six coals using the SIT, R70 adiabatic testing procedures, as well as the CPT semi-adiabatic testing procedure. Then we compared and evaluated the results from each measurement method and discussed their applicability toward stored coal management. As a result of the measurement, we confirmed that the R70 adiabatic testing procedures and the CPT semi-adiabatic testing procedure show similar tendencies of spontaneous heating. In addition, it was suggested that the MAB test method measurable on the basis of arrival coal samples, would be suitable for prompt measurement of coal with high spontaneous heating characteristics.

Coal Adiabatic Spontaneous Heating (CASH) of two coals with very similar analysis but very different heating properties and their mixtures was observed with the CASH measurement apparatus under the oxygen flow by starting at 35°C. The blending of the reactive coal with the much less reactive coal is found to accelerate the heating of the mixtures much more than that expected on their mixing weight ratios. The mobility of the active oxygenating species among the coal particles is postulated in addition to the thermal acceleration by the reactive coal.

A numerical simulation of coal gasification on an oxy-fuel type entrained flow coal gasifier coupled with the extended Chemical Percolation Devolatilization(CPD) model and the elementary reaction model was performed to validate and demonstrate the capability of the present numerical procedure by means of Reynolds-averaged Navier-Stokes(RANS) simulation in this study. Benzene, naphthalene and phenanthrene were specified as tar contents during the pyrolysis in the extended CPD model. The chemical mechanism that includes 76 chemical species and 134 elementary reactions was employed. Results show good agreements with the experimental results such as temperature distribution and product gas composition. In addition, detailed characteristics of tar decomposition and polymerization, soot formation and so on were discussed in this paper. It was demonstrated that the present numerical procedure was strong tool to understand the complex physics taking place in the coal gasifier.

Char gasification reaction is the rate-determining step in coal gasification reactions. We have been developing char gasification kinetic analysis method utilizing drop tube furnace as well as thermogravimetry. In the method, we analyze char gasification using three kinds of gasification model considering (1) chemical reaction on active sites, (2) changing of pore structure or specific surface area and (3) diffusion control area at high temperature. These models are necessary to describe totally char gasification phenomena and the experimental methods are useful to get the kinetic parameters.

In this study, to shorten gasification reaction time of mixed fuel of low grade coal and biomass, different kinds of biomass and coal were used. We investigated the most suitable combination of biomass and coal type. After the pyrolysis, the gasification experiment was conducted with mixed char of low-grade coal and biomass under the different temperatures and CO₂ gas. As the results, gasification reaction of mixed char of low-grade coal and rice straw was effective. It was assumed that the ash contents of the mixed fuel play the catalytic functuon in mixed gasification.

Since April 2012, Osaki CoolGen Project was launched as an “Integrated coal Gasification Fuel Cell combined cycle (IGFC) demonstration project” with the support of Ministry of Economy, Trade and Industry (until 2015 FY), and New Energy and Industrial Technology Development Organization (from 2016 FY). This project consists of the following three steps. In the Step 1, oxygen blown IGCC is demonstrated. In the Step 2, IGCC with CO₂ capture is demonstrated. In the Step 3, IGFC with CO₂ capture is demonstrated. Demonstration of the Step 1 has started since March 2017. Development targets of plant efficiency, environmental performance, equipment reliability, and operability were achieved. Currently, coal variety compatibility and economic efficiency will be confirmed. This paper describes detail and progress of Osaki CoolGen Project.

Victorian brown coal in Australia is an important resource because of its huge reserve and low mining cost, and is only used for power generation near its mine. After oil crisis during 1970s, the BCL (Brown Coal Liquefaction) process has developed to liquefy it into transportation fuel, but it is not commercialized because the coal-derived fuel is not competitive economically with petroleum. The coal-liquefied products contain poly-aromatics, heterocyclic compounds and pitch, which have potential to be used as feedstocks for coke-binder and carbon-materials. When the products are used as chemical feedstocks, their value increases compared to fuel; the plant capacity and liquefaction conditions become small and mild. This means that the configuration of the BCL process is modified and the cost of the coal-liquefied products decreases. As a result, the modified BCL process is able to become an efficient and noble utilization technology of the brown coal.

We have proposed a novel highly-efficient power generation method in which low-rank coal or biomass reduces liquid phase metal ions and subsequently electric power is generated by electrochemical oxidation of the reduced ions by air. Whereas power generation efficiency by brown coal or biomass using a conventional boiler is only 10–20 %, theoretical power generation efficiency of the proposed method can be estimated to be as high as 80 % if VO²⁺ or Cu²⁺ is employed as metal ions for example. We have recently showed that the reduction of candidate metal ions, VO²⁺, by low-rank coal or biomass can proceed at as low as around 250 °C. However, the reduction reaction was retarded before high conversions of VO²⁺ and low-rank coal or biomass were reached. In this study we performed a kinetic study to clarify the reason for the retardation.

It is requested to maximize the Soluble yield with minimum energy requirement from practical viewpoint to realize the proposed solvent degradative extraction technology. To do so, it is essential to minimize the solvent to Soluble ratio or the treatment. A new operating scheme, which uses the Solube-solvent mixture repeatedly as the solvent treating biomass before separating Soluble from the solvent by replacing around 10 % of the mixture by fresh solvent every time, was proposed. The validity of this operating scheme was examined by treating a Thai rice straw with a general-purpose petroleum based solvent called A150 through 10 times of repeated use of Soluble-A150 mixture.

The main outcomes of the study are as follows: (1) The volatile yields of woody biomasses can almost be predicted by using H/C ratio. (2) In the case of coal-oil, BTX and cresol accounted for the majority of the components. On the other hand, in biomass-oil, a prominent increase in the yields of chemical species containing O and OH groups was observed. (3) In case of woody biomass, acetic acid, glucose, phenols, and furfural were revealed as the major bio-tar components. (4) The tar components obtained from woody/grass biomass were affected by the amounts of the constituents.

Dehydrocyclization-cracking of soybean oil, which generates aromatics and hydrogen simulataneously, was developed by preparing multi-functional zeolite-oxide composite-supprted PtNiMo catalysts, which have properties of acid by zeolite, hydrogenation and dehydrogenation by transition metals, and mesopore by matrix oxide. Using Pt/NM/β(37)60Al gas selectivity was inhibited to 19% and showed 65% of the highest selectivity for liquid fuels of C5-C18 (gasoline selectivity 51%) under the condition, 0.5MPa and 580°C. Pt/NM/β(37)60Al showed 12% of the highest selectivity for CO, CO₂ under the condition, 1.0MPa and 580°C. Pt/NM/β(11)60Al showed 16% of aromatics yields under the condition, 1.0MPa and 580°C. The use of TiO₂ decreased the gasoline fraction while the use of ZrO₂ decreased the conversion. The use of KL-zeolite also decreased the gasoline fraction.

We have proposed the so called degradative solvent extraction that dewaters and upgrade low rank coals and biomass wastes at around 350 °C. The smallest molecular weight fraction, Soluble, which is free from either water or mineral matters is expected to be a precursor of carbon materials. In this presentation we examined the effect of raw materials and solvents used on the properties of carbon fiber and activated carbon fiber prepared. A Thai lignite, Mae Moh, and a Thai rice straw were used as raw materials. 1-methylnaphthalene and a petroleum based solvent, A150, were used as solvents. It was found that hollow fiber can be prepared under controlled conditions. The carbon fiber was converted activated carbon fiber as one of final products, and the properties of the activated carbon were examined in detail.

Carbon dioxide Capture, Utilization and Storage (CCUS) is a technology to control the climate change of the earth, and active proposal development in the future is desired. The "Paris Agreement" on climate change control, which was concluded in December 2015 and came into effect in November 2016, attracts attention, and patent applications are also increasing in recent years. Against this backdrop, the JPO conducted a survey on market trends, policy trends, patent application trends, research and development trends, etc. on "Carbon dioxide Capture, Utilization and Storage" in the Survey on patent application technology trends in FY2009 The contents were announced.

It has been recognized that the CO₂ separation and recovery process accounts around 60% of the total cost for operating CO₂ capture and storage (CCS). The CO₂ chemical absorption with a conventional amine solvent like monoethanol amine requires around 4 GJ/t-CO₂ for CO₂ recovery. Recently we developed phase separation solvent system which consists of not only amine but also hydrophobic solvent, ether. This system, before CO₂ absorption, we have single phase, while after CO₂ absorption, we have phase separation, one is CO₂ rich phase and the other is CO₂ lean phase. We can expect that the energy can significantly be reduced because it is not necessary to regenerate whole solvent but only the CO₂ rich phase is to be regenerated. In this study, we examined the phase phenomena for 9 types of amine and a hydrophobic solvent mixture before and after CO₂ absorption to find phase separation solvent system to minimize energy for CO₂ recovery. Based on the observation, the mechanism for the phase separation and solvent regeneration is also discussed.

The solubility parameter (δ [J/cm³]^1/2) defined by J. H. Hildebrand in the study of regular solution theory is the inherent physical properties given by the square root of the cohesive energy density of the substances (gases, liquids and solids), generally known as the SP value¹⁾. Even today, the SP value is widely used for evaluating solubility, wettability, adhesiveness between materials and, and dispersibility of fine particles in a solvent ²⁾. C. M. Hansen defined the cohesive energy term of SP value proposed by Hildebrand as three interactive energy acting between molecules. These are the London dispersion force term (δ_d [J/cm³]^1/2), the dipole interaction force term (δ_p [J/cm³]^1/2), the hydrogen bonding force term (δ_h [J/cm³]^1/2), and proposed as Hansen's solubility parameter (HSP value) ^{4) 5)}. In recent years, Hansen's research group has developed a Hansen solubility sphere method(HSPiP) as a new method to experimentally obtain HSP values of polymers, resins, fullerenes, carbon black, asphaltenes, polymeric hydrocarbons etc. whose molecular structure is unknown ³⁾. This method can determine the HSP value of many materials which has been difficult to calculate so far, its versatility is so wide, and it is attracting attention from many researchers ^{6) 7)}. In this paper, we will present on fundamentals of Hansen solubility parameter, new group contribution method of HSP value from molecular structure and application examples of Hansen solubility sphere method to polymer hydrocarbons ^{6) 7)}.

This paper summarizes molecular models of asphaltene and synthetic model compounds in past studies. Asphaltenes were considered to contain continental-type and/or archipelago-type molecules. The former consists of one large polycyclic aromatic unit with side chains, and the latter have several small polycyclic aromatic units that are connected to each other. In the last decade, researchers have tried to synthesize model compounds of asphaltene. For example, hexabenzocoronene with straight side chains as a model of continental-type molecules, and a nickel porphyrin-derived compound, pyrenederived compounds, and steroid-derived naphthoquinoline compounds as models of archipelago-type molecules. However, the model compounds neither have the same chemical structures as the proposed molecular models, nor show similar aggregation behavior as asphaltene.