With the entry into force of the Paris Agreement, the role of the financial sector is attracting attention as actions aimed at zero emissions globally have become apparent. Structural changes have been brought about by promoting decarbonization through financial markets, such as the push for disclosure of non-financial information by companies on climate change issues and the EU's development of sustainable technical standards (taxonomy). On the other hand, the need to strengthen energy systems against natural disasters has been addressed as a point of contention. As there is a deep relationship between climate change countermeasures and the resilience of energy systems, it will be important in the future to consider financial sector portfolios that contribute to solving mutual issues.

Renewable energy has been rapidly used in the last 20 years for the great reduction of CO₂ emission into the atmosphere and the development of sustainable society. In this presentation, the following issues regarding biomass power generation systems are summarized: (1) many restrictions of biomass power generation systems such as (1-1) very low energy efficiency from solar power to electricity, (1-2) limiting amount of resource, and (1-3) requirement of fuel cost for operation, and (2) characteristics of combustion technologies including drawbacks and the following strong points: (2-1) high power, (2-2) high-temperature heat generation, and (2-3) utilization for hygiene or sanitation purposes. and I propose 3) next-generation biomass power generation systems integrated with variable renewable energy (VRE) and energy storage system for dynamic operation are proposed as a promising method to balance the intermittent electricity supply by VRE and electricity demands. The reduction of simple combustion and the noble use of combustion technology by effectively utilizing these strongpoints are needed to greatly reduce CO₂ emission even if renewable biomass is used

There are various types of gas-solid contacting reactors. Fluidized bed is one kind of gas-solid contacting reactor and employed for various processes. However, a feature that is advantageous for one application is sometimes found to be a disadvantage for another application. Therefore, engineers should prepare various types of gas-solid contact reactors as many as possible so that they can choose the most suitable one. The present author has proposed a novel gas-solid contacting reactor called “rotating coil-shaped spiral”. This article briefly summarizes the state-of-art of the development of “rotating coil-shaped spiral” reactor concerning to solid transportation, gas-solid contact and pressure drop during gas feed, and heat transfer between wall and solids. The future perspective is also discussed.

For the plastic resource circulation, recycling plastics back into plastics is not necessarily an only solution. A rational pathway to contribute to realization of a decarbonized society lies in a replacement of fossil resource-dependent flows with waste plastics in a wider carbon cycle of the economy. Therefore, we need a discussion based on quantitative analyses including the roles of chemical recycling methods and energy recovery, separately from the abstract concept whether the recycling loops are inner or outer. Positioning chemical recycling and energy recovery of waste plastics in the industry-wide strategy for decarbonization should be a principle of the plastic resource circulation in Japan.

C1 chemistry is extremely focused now as it deals with syngas, carbon dioxide and methane conversion by varied catalysts and processes. We are researching and developing novel catalysts and new reactions which directly synthesize light olefins, gasoline, jet fuel, as well as aromatics including para-xylene via FT synthesis and methanol synthesis, accomplished by new and significantly powerful capsule catalysts. In this report, we introduce one-pass selective conversion of syngas or carbon dioxide, to para-xylene. And some other new C1 chemistry reactions such as ethanol synthesis from syngas and dimethyl ether are also elucidated. Furthermore, metal 3D printing technology for functional integration of C1 chemistry catalytic system is disclosed.

In this paper, author introduce Mobility Management (MM), which has been developed as an urban transport measure based on social psychology in order to change people's behavior (mainly travel behavior) to a more socially desirable direction. In this presentation, author will introduce some examples of the application of MM to urban planning, such as the choice of residential area in consideration of public transport, landscape, revitalization of city centre. The techniques of MM, which encourage people to voluntarily behavior change, can be applied to mitigate various social problems with a social dilemma situation. Furthermore, it may be effective to combine these communication measures with infrastructure development, legal systems and economic policies.

Biomass (bioenergy) has features of carbon neutrality, long distance transportable and stackable hydrocarbon, and multi-uses such as food, feedstock, and energy. Carbon neutrality is originally the term that explains net CO₂ emissions of sustainable biomass uses, but it becomes the concept of the goal of the whole energy systems. Biomass can realize not only the carbon neutrality but also the carbon negative emissions when the captured carbon in the biomass is not discharged. In this document, it is explained that biomass uses in Japan in this century is affected by feed-in-tariff and other policies. Then, biomass uses in Japan to head toward low emissions energy systems is discussed.

A mathematical model of material flow analysis (MFA) based on Waste Input-Output model (WIO) (Nakamura and Kondo) is presented. The model (WIO-MFA) is based on two fundamental ingredients: yield ratios and the degree of fabrication. In the manufacturing process, multiplication of physical inputs by the yield ratios gives the portion that enters physical outputs, with the rest being discarded as process waste without entering outputs. In input-output analysis, the degree of fabrication can be visualized as triangularity of the input coefficients matrix (goods of a lower degree of fabrication can enter those of higher fabrication, but the reverse does not hold), which is known to emerge through an appropriate reordering of sectors. Application to the Japanese IO data indicates that the model can provide accurate estimates of the weight and the composition of metals (Fe, Cu, Pb, Zn, and Al) used in a passenger car. Furthermore, combined with the information on embodied energy, WIO-MFA can depict the energy flow in terms of intermediate flows.

Utilization technology of low-rank coals is extremely important to keep stable supply of coal which is one of essential resources to enhance energy security in Japan. In this study, the mineral liberation by coarse pulverization was investigated using two types of coal with different ash content and ash composition. The mineral liberation characteristics were evaluated from contents of organic matter and mineral of the pulverized coal particles, whose median diameters were around 0.45 mm, obtained by coarse pulverization using three types of pulverizers. As a result, the mineral liberation characteristics were different for each pulverizer. The results of some analyses suggested that the difference of liberation characteristics depends on mineral distribution and composition in the coals.

Pyrolysis and combustion process of brown coal was investigated by the isothermal thermogravimetric technique at several different operating temperatures using the vertical and horizontal fixed bed reactor. Gas chromatography analysis was employed to characterize the composition of generated gas during the pyrolysis and combustion processes. The activation energy (EA) and pre-exponential factor (A) were determined using first-order reaction for both processes. The combustion results showed that the activation energy decreases with increasing oxygen concentration, and the burnout time could be achieved from the oxygen concentration and combustion temperature. The main generated gaseous for pyrolysis were H₂, CH₄, CO and CO₂.

The Osaki CoolGen Project is aiming to realize the revolutionary low carbon coal fired power generation through the combination of Integrated Coal Gasification Fuel Cell Combined Cycle (IGFC). This project consists of three steps. In the first step, a demonstration of oxygen-blown Integrated Coal Gasification Combined Cycle (IGCC) has been successfully completed. In the second step, oxygen-blown IGCC with CO₂ capture is currently demonstrated. In the third step, IGFC with CO₂ capture will be demonstrated from 2022.

In this study, a zeolite-containing hierarchical catalyst having micropores on the inside and mesopores on the outside was prepared in one step under low temperature conditions using the gel skeletal reinforcement method at the preparation of zeolite simultaneously. The influence of the preparation temperature and aging time on the development of zeolite and mesopores in the catalyst was examined by characterization of catalysts and the reactivity for catalytic cracking of n-dodecane. At 100°C and higher than 100°C and 48 h aging time and longer than 48h, zeolite crystals and silica with large mesopores developed simultaneously. A catalysts prepared at 100°C of crystallization temperature and 48h of aging time (CR100 (48h)) showed the highest conversion in n-dodecane cracking. Although the crystallinity of ZSM-5 was higher in CR100(72h), the conversion of CR100(48h) was higher than that of CR100(72h) probably because of the presence of large mesopores.

We investigated direct conversion of dilute CO₂ into CH₄ without CO₂ purification under various reaction conditions over Ni-based dual-functional catalysts. Ni/Na/Al₂O₃ showed the highest performance with high CO₂ conversion (>96%) and CH₄ selectivity (>93%) for 5% CO₂ capture and reduction. In addition, very low CO₂ levels of 100 ppm were successfully converted to 11.5% CH₄ at a peak point over Ni/Na/Al₂O₃, which was more than 1000 times higher concentration than that of the supplied CO₂. These results suggest that efficient dual-functional catalysts are promising for CO₂ utilization, thus enabling direct air capture-conversion to value-added chemicals.

As one of the Holy Grail reactions in C1 chemistry, direct selective oxidation of methane to methanol under mild and non-harsh conditions remains a big challenge. Hydroperoxide (H₂O₂), as a primary oxidant, applied widely in the lowtemperature direct selective conversion of methane to methanol. Moreover, the hydrogen and oxygen mixture gas achieves better reaction activity and higher methanol selectivity than H₂O₂ when using palladium-gold (Pd-Au) bimetallic nanoparticles as the catalyst. In this paper, we studied the key roles of the physical and chemical characteristics of Pd-Au nanoparticles in this direct selective oxidation reaction with hydrogen and oxygen as the oxidant at 50°C. For further clarifying the physical and chemical characteristics of catalysts, X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Hydrogen-Temperature-programmed reduction (H2-TPR), and CO pulse adsorption measurement (CO-PULSE) analysis methods are also measured.

Capsule catalyst, being composed of catalytic zeolite membrane and catalyst core, can accomplish multiple catalysis reactions or several organic synthesis reactions in a single step, enhancing energy efficiency, erasing unnecessary separation engineering and creating many unexpected synergistic effects via tandem catalysis. This report discloses an ethanol synthesis strategy from syngas (CO+H₂) and syngas-derived dimethyl ether (DME) by a tailor-made catalyst with a macroscopic capsule structure. As the methanol byproduct can be easily recycled to DME as reactant via simple dehydration reaction, ethanol selectivity can reach 100% theoretically. It is demonstrated that a space-confined-self-regulation (SCSR) mechanism derived from macroscopic capsule structure serves as a multifunctional switch to manipulate tandem reactions: arranging reaction steps in a favorable order and depressing side-reactions simultaneously.

In the sea area around Hokkaido, the existence of bottom simulating reflectors (BSR) has been confirmed off Abashiri, Okushiri Island, Hidaka, and Tokachi. In November 2020, we succeeded in collecting methane hydrate present in the surface layer of the seafloor in the Pacific Ocean off Tokachi. Attempts a direct reforming methane dissociated from the methane hydrate, was successfully hydrogen generation by a chemical reaction that does not generate carbon dioxide. In addition, carbon could be recovered as carbon nanotubes with high utility value.

We tested the performance of various hydrate crystal growth inhibitors (HCGIs). We used a tetrahydrofuran (THF) sII hydrate system using a unidirectional growth apparatus. The HCGI concentration c = 0.5 wt%, and growth rate V is variable. These results enhance the persuasiveness for the model that the HCGI effect is explained by the residence time on the crystal surface of HCGI, τ, and duration time t* of crystal growth. We determined the threshold growth rate of THF hydrate for examining HCGI performance on sII gas hydrate.

Gas hydrates can store copious amounts of guest gas molecules and it is expected to be used as a gas storage medium. Since it is required to efficiently form gas hydrate for the purpose of gas storage, we focused the effect of specific surface area on the purity of gas hydrate. We formed gas hydrate samples using fine ice powder and high-pressure methane, measured specific surface area of the samples, and estimated their purity supposing that the hydration number of methane hydrate was 6. The purity of methane hydrate showed maximum at around 250K. In the case of high temperature, decrease in the specific surface area of methane hydrate affected the formation speed of methane hydrate.

In November 2020, massive samples of natural gas hydrate were recovered off Tokachi (the Pacific Ocean) in the C095 cruise using T/S Oshoro-Maru of Hokkaido University. It was the first successful recovery of natural gas hydrate in the Pacific Ocean off Tokachi. We measured the bulk density of the sample and revealed that it was 607±6kg m⁻³, whereas that of pure methane hydrate is 915kg m⁻³. X-ray CT image of the sample showed that it contained many gas bubbles. Crystallographic analyses suggested that the hydrate belonged to the structure I and contained mainly microbial methane.

Visualization of clathrate hydrate coexisting with water and ice in a nondestructive manner is very effective for evaluating its stability. However, conventional methods such as white X-ray CT and MRI cannot distinguish ice from clathrate hydrate. In this presentation, the results of our attempt to visualize various clathrate hydrates by using monochromatic absorption contrast X-ray CT method with low energy X-ray using synchrotron radiation will be presented.

TBAB (Tetra-n-butylammonium bromide) hydrate has a phase change temperature of 5 to 12°C and is expected to be used as a latent heat storage material for air conditioning systems. Generally, TBAB hydrate shows a remarkable supercooling phenomenon at the time of formation, but it can be suppressed by adding specific metal particles having a nucleation promoting effect. In this study, we investigated changes in the performance of metal particles by adding metal particles to a TBAB aqueous solution and repeating the formation and melting of hydrates. Moreover, we investigated changes in the performance of metal particles by immersing them in TBAB aqueous solution for a specific number of days. As a result, it was found that the performance of metal particles is significantly reduced by repeatedly using the particles or immersing them in TBAB aqueous solution.

We investigated the thermodynamic properties of semiclathrate hydrates (SCH) depending on tetragonal tetra-n-butyl ammonium bromide (TBAB) and tetra-n-butyl ammonium chloride (TBAC) guest mole fractions by ion chromatography and differential scanning calorimetry. TBAB mole fraction rates in TBAB + TBAC mixed SCH (y^hTBAB) are lower than those in mixed aqueous solutions; it means that Cl⁻ with a smaller size difference to a water molecule is more easily incorporated into the host frameworks of SCH than Br⁻ in mixed SCH systems. The melting points of mixed SCH were observed at 286–289K, and the maxima are around y^hTBAB = 0.1–0.3 in each hydration number. Dissociation enthalpies per guest moles increase linearly from 154kJ mol^–1 to 188kJ mol^–1 primarily depending on increasing hydration numbers.

Tetrahydrofuran (THF), one of the most popular clathrate hydrate formers, forms the structure-II (sII) hydrate at temperatures below 277.5 K and atmospheric pressure. The sII unit lattice consists of 16 small 5¹²-cages (S-cages) as well as 8 large 5¹²6⁴-cages (L-cages). A THF molecule occupies the L-cage, whereas the S-cage remains vacant. The application of vacant S-cages, that is, the enclathration of another guest species into S-cages, has been investigated in the fields of gas separation or storage media. It has been reported that, as another guest species, tetra-n-propylammonium fluoride (N3333F) can be enclathrated in the sII clathrate hydrate with THF (Manakov et al., J. Incl. Phenom. Mol. Recogn. Chem., vol. 17, pp. 99-106 (1994)). In the present study we investigated thermodynamic stabilities of (THF + quaternary onium salt) hydrates.

Tetra-n-butylammonium chloride (TBAC) semiclathrate hydrate was synthesized with changing TBAC concentrations. The hydration number of the obtained samples decreased as the TBAC concentration increased. Powder X-ray diffraction data showed that the crystal structure had the tetragonal symmetry and that the peak intensities of both 200 and 220 increased with decreasing hydration. Due to the large molecular size of TBA molecules, their position within the unit cell cannot be significantly changed. Crystal structure analysis by the Rietveld method indicates that chloride ions changed their atomic coordinates with changes in hydration. The chloride ion positions are effective in causing changes in the peak intensity of XRD, because chloride has the largest atomic number in TBAC semiclathrate hydrate.

Biomass, including livestock excrement, is increasingly being used for energy. Livestock excrement causes problems of air and water pollution. For this reason, the technology of methane fermentation is often used in order to treat it properly and make effective use of it. However, in methane fermentation, the nitrogenous components of the biomass form ammonium ions, which inhibit the fermentation. In order to avoid this problem, we have succeeded in using hydrothermal pretreatment to convert nitrogenous components into ammonium ions before methane fermentation, which are then recovered as ammonia. We have also investigated the reaction rate of nitrogen components in poultry litter.

Sawdust was pyrolyzed with the porous carbon in the batch reactor to obtain the resource gasses with the deposited carbon fixed on the solid. The yields of H₂, CH₄, CO₂ increased through the secondary decomposition of tar fraction, which generated between 300 and 400°C. With activated carbon, carbon was deposited on the surface of activated carbon through the secondary decomposition of tar fraction. The generation of CH₄ is promoted to improve the H recovery ratio, and the most of deposited carbon could be recovered with activated carbon. Similar effect was obtained when pyrolyzed char of sawdust was used instead of the activated carbon.

In recent years, biomass gasification technology has been attracting more and more attention as an environmentally friendly biomass conversion technology. Biomass char gasification is the most important step of the overall operation of biomass gasification. The char gasification reaction is the limiting step in the global gasification reaction and is of major importance in designing biomass gasifier. In this study, biomass char gasification experiments in H₂O, CO₂ and their mixtures were carried out in a batch type vertical tube furnace. The gasification characteristics and temperature dependence of biomass char in various gasifying agents were experimentally investigated. We also studied the mixed atmosphere gasification and found the char reactivity in a mixed atmosphere of steam and carbon dioxide can be expressed as the sum of the individual reactivity obtained in single atmosphere gasification experiments.

Demonstration tests for bench-scale updraft type biomass gasification system that we have developed is performed using semi carbides. Difference in the amount of gas generated in the carbonization temperature 300°C and 350°C is remarkably observed. In order to control the reaction and heat transfer inside the gasification reactor more efficiently, it is important to search optimum temperature for semi carbonization. Therefore, we clarify influence of temperature of semi carbonization to the amount of generated gas and its composition, by experiments for gasification of semi-carbides of various types of coniferous trees and broadleaf trees.

It is known that fast pyrolysis of cellulose produces a large amount of levoglucosan, which can be saccharified under mild conditions. This fast-pyrolysis-base saccharification may apply for the production of polylactic acid (a bioplastic) via lactic acid fermentation. However, the pyrolysis of cellulose generally gives by-products, which may inhibit the fermentation. In this study, we investigated the lactic acid fermentability of the sugar solution as prepared via the fast pyrolysis of cellulose under the irradiation of IR. As a result, lactic acid fermentation proceeded for a low concentration sugar solution (11.1 g/L), but not for the high concentration (22.2 g/L). Then, we investigated the inhibitors and the removal way to improve the fermentability for the high concentration sugar solution.

Levoglucosan (LG) is an important primary pyrolysis product from cellulose in fast pyrolysis, but secondary pyrolysis reactions tend to reduce the yield. In the present study, cellulose was pyrolyzed by infrared heating under nitrogen flow. Because the nitrogen was not efficiently heated, the gaseous LG would be immediately cooled. The maximum yield of LG was 52.7 wt% under optimized conditions in this study. In addition, a new mechanism was clarified in which the pyrolysis of cellulose proceeded within a narrow region of carbonized material that absorbed infrared irradiation more efficiently. This is a feature of infrared heating, and high yields of LG were obtained regardless of the sample size.

Thermogravimetric analysis (TGA) has been frequently utilized to evaluate the thermal degradation reactivity of wood and the component polysaccharides. Softwood and hardwood species are clearly discriminated by TGA; hardwood exhibits a clear low-temperature-shoulder along with a peak in derivative of TGA (DTG) curve, whereas the softwood DTG curves do not show such a shoulder. Such difference is believed to arise from the different hemicellulose composition by comparing with the DTG curves of the isolated polysaccharides, but no evidence has been reported. In wood cell walls, the constituents have a nano-multilayer structure, in which cellulose microfibrils are surrounded by the matrix of hemicellulose and lignin. Such nano-structure may affect the thermal degradation reactivity of cellulose and hemicellulose in wood. In this study, thermal reactivity of cellulose and hemicellulose in wood was directly evaluated by quantifying the amounts of cellulose and hemicellulose remaining in the heat-treated Japanese cedar (Cryptomeria japonica, a softwood) and Japanese beech (Fagus crenata, a hardwood). As a result, thermal degradation reactivity of cellulose and hemicellulose in wood was found to be quite different from the isolated polysaccharides, and the influences were different depending on the wood type. Finally, the different TG/DTG curves of softwood and hardwood species are clearly explained by the thermal degradation reactivity of cellulose and hemicellulose.

In wood gasification, by-production of tar and coke causes problems such as clogging of pipeline, but the formation mechanisms are not clear. The wood components are considered to behave differently in this process. In this study, we conducted pyrolysis experiments of isolated components of wood, that is cellulose, lignin, xylan, and glucomannan, in a wide temperature range up to 1000°C, to investigate the tar and coke formation behavior of each component.

The decomposition of woody biomass in water-added supercritical methanol can produce lignin-derived monomers in high yields and high selectivity. However, the decomposition behavior and mechanism have not been fully revealed yet, limiting the application of supercritical alcohol technology for chemical production. Therefore, the effect of reaction conditions, such as pressure, flow rate, was studied with a semi-flow reactor, to investigate the reaction behavior. The results showed that treatment at 270°C with high pressure exhibited good delignification performance by promoting the decomposition and solubilization of lignin.

Xylitol is one of most important biorefinery platform chemicals for production of C5 chemicals. Ru, Ni, and Cu nanoparticles loaded on metal oxide support are generally used for xylitol production via hydrogenation of xylose, but these catalysts can result in low xylitol yield because of undesired reactions occurring on active sites on the metal oxide support and at relatively high reaction temperature (> 150°C). Therefore, the metal nanoparticles loaded on carbon support with high activity at low temperatures is considered to be preferable for selective production of xylitol. In this study, we synthesized carbon supported Cu nanoparticles catalyst (Cu@C) with small Cu particle (14nm) by using an ion-exchange resin as a carbon source. Because of the large Cu accessible surface area of Cu@C, high xylitol yield (31C-mol%) and xylitol selectivity (73C-mol%) were obtained by xylose hydrogenation over Cu@C at 130°C and 0.2g-Cu/g-xylose for 24h. Additionally, hydrogenation of xylose to xylitol and hydrodeoxygenation of xylitol proceeded in series during the reaction over Cu@C, suggesting there was optimal reaction time to maximize xylitol yield.

Carbon-CeO₂-ZrO₂ composite-supported Co catalysts were prepared by the sol-gel method using PEG as a carbon source and were used for the steam reforming of ethanol (SRE). SRE was carried out using a fixed-bed flow reactor under the condition, a reaction temperature of 300-600°C, LHSV = 48h^-1 and H₂O / EtOH (mol / mol) = 12 and the products were analyzed by GC-FID and GC-TCD. Nitrogen adsorption and desorption, XRD, XRF and TG-DTA measurements were performed as characterization of the catalysts produced. When the reaction initiation temperature was changed from 300°C to 500°C, the ethanol conversion reached 100% at 500°C and higher than 500°C for every catalyst and every initiation temperature. However, the hydrogen yield changed depending on the ratio of CeO₂/ZrO₂ and the initiation temperature. When 16Co42C31.5Ce10.5Zr with higher ratio of CeO₂/ZrO₂ was used, the higher yields of hydrogen were obtained at the initiation temperature of 300°C and 400°C. Further, the higher hydrogen yields were obtained regardless of the initiation temperature for 16Co42C21Ce21Zr, but were obtained at 400°C and 500°C for 16Co42C10.5Ce31.5Zr.

The development of catalysts for the decomposition of biomass tar is one of the major challenges for the low-temperature gasification of biomass. In this study, we focused on the Ni-loaded hydroxyapatite (HAP) catalysts for tar decomposition. The effects of Ca/P in HAP on the catalytic activity of Ni/HAP catalysts for the tar decomposition were investigated because the catalytic activity of the HAP is known to vary with its Ca/P. The results indicate that the Ni-loaded HAP with higher Ca/P showed higher catalytic activity to decompose of both actual biomass tar and phenol used as a model tar.

Catalytic transfer hydrogenation is effective for the conversion of biomass to liquid fuel. Therefore, catalytic transfer hydrogenation of cellulose was investigated using straight-chain aliphatic hydrocarbon solvent as a hydrogen source.

Cellulose in this solvent is converted into polar components with high-molecular weight at 300°C. The components are changed into ketones with the carbon number >C6 by decomposition and dehydration with aldol-condensation. The ketones are hydrogenated to straight-chain and aromatic hydrocarbons with 7 or more carbon atoms at 350°C.

We have been developing a new hydrocarbon-based biodiesel fuel, HiBD (High quality Bio Diesel), which is produced through MgO-catalyzed decarboxylation of triglycerides. We have already demonstrated that high yield and selectivity of hydrocarbons of diesel fractions can be obtained using solid catalyzed vapor phase reaction in a pilot scale plant. However, long time operation was found difficult due to carbon deposition on the catalyst. In this research, we developed a novel slurry phase reaction system and a catalyst which is suitable for the system. Also, sudden boiling of the feed oil observed during the initial heating process was investigated.

Acylglycerols, such as monoacylglycerol (MAG), diacylglycerol (DAG), and triacylglycerol (TAG), are minor components in biodiesel (fatty acid methyl ester, FAME). Because high melting points and the polymorphic nature of acylglycerols affect the cold flow properties of biodiesel, their solidification behavior was investigated in this study. The liquidus temperatures of binary mixtures of FAME, MAG, DAG, and TAG were determined by differential scanning calorimetry. The results were compared with estimates from three thermodynamic prediction models: ideal solution (IS), non-ideal solution (NIS), and compound formation (CF) models. The role of each acylglycerol species in the development of prediction models for the cold flow properties was discussed.

In biodiesel and fossil diesel blends, highly viscous phase-separated products were generated as the oxidation reaction proceeded, but there is no previous research on this phenomenon. In this study, the phase-separated products were characterized by various chemical analyses. In addition, oxidative degradation tests were conducted using binary mixtures of n-heptadecane and methyl linoleate. The results showed that the phase-separated products were mainly oxidation products from fatty acid methyl esters with carboxyl groups. It is thought that the formation of carboxyl groups by oxidation increased the polarity and cause phase separation from the hydrophobic fossil diesel. It was also suggested that alkanes in fossil diesel, which are inherently stable, contribute to the radical chain oxidation of biodiesel.

In previous studies, performance tests using Bio diesel fuel (BDF) in small diesel engines showed that that increased PM emissions are suppressed under conditions of reduced oxygen concentration. Elsewhere, the kinematic viscosity of BDF is higher than that of gas oil, which is considered to be disadvantageous for rendering the fuel spray finer. This study compared the effects on thermal efficiency and exhaust gas of changing the fuel injection pressure, which affects finer fuel spray, in a diesel engine using gas oil and BDF. The study found that the difference in operating characteristics depending on the fuel used is reduced when the fuel injection pressure is increased to 200MPa. However, at lower fuel injection pressures, the exhaust gas component deterioration is suppressed when using BDF.

Isothermal vapor-liquid equilibria (VLE) were measured for ethanol–heptane by use of a modified Rose-Williams equilibrium still combined with ebulliometer at 363.15, 393.15 and 423.15 K. The apparatus enable VLE measurements not only for isobaric 101.33 kPa, but also for isothermal conditions. The experimental data showed a similar tendency to the data of literature at 343.15 and 483.15 K, and were well correlated with improved Peng-Robinson (PRSV) equation of state. Applying Eyring theory, PRSV equation was extended to the prediction for the liquid viscosity data. The method will contribute to design for engines using fuels mixed with bioethanol.

Sorghum is expected as a fuel crop. This study investigated the relationships between the heating value and the contents of the main components, that is cellulose, hemicellulose and lignin for sorghum. The ash-free content of each component was estimated by measuring the ash content in the residue in each process of the component analysis. Multiple regression analyses were carried out using the ash-free contents of the three components as the explanatory variables and the heating value as the objective variable. As a result, a highly accurate correlation equation to predict the heating value from the component composition was obtained.

We focused on the photoluminescence (PL) of lignin, and studied the influence of lignocellulosic species, extraction methods, solvents and polymers on their photoluminescence properties. Various lignins were prepared using four different taxonomic species such as Japanese cedar (softwood), Japanese beech (hardwood), nipa palm (palmeae) and corn (poaceae), and five different extraction methods such as milled wood lignin preparation and Kraft pulping. From the PL spectrophotometry, all lignins apparently showed the PL and their spectral patterns were different one another depending on their species and extraction methods. When comparing the PL spectra under various solvents, lower PL intensity was observed in hydrophobic solvents. According to the characterization of solubility behavior of lignin in N,N-dimethylformamide and chloroform solution, the aggregation of lignin was observed only in chloroform solution. The aggregation approximated the distance between lignin molecules, resulting in quenching of its PL. In other words, quenching of PL can be mitigated by controlling the formation of lignin aggregates. Based on this knowledge, lignin was homogenously dispersed in polymer solution, and the transparent photoluminescent film was successfully obtained. Furthermore, the PL properties of films were different depending on the polarity both of solvent and of polymer.

International standards are international arrangements for product quality, performance, safety, dimensions, test / inspection methods and so on. Since the ISO solid biofuels was first published in 2014 by ISO/TC 238, the number of the documents has reached 45. Some of the standards are being subjected to systematic review, done in every five years. In such a situation, the domestic committee for TC 238 was established in early 2021. However, Japan has been an O member, and therefore no right to participate ISO standards for solid biofuels. In this paper, the authors will discuss the issues for Japan to participate TC 238, introducing revision of the ISO standards for solid biofuels and the differences between ISO and the domestic voluntary standards.

Woody biomass is regarded as carbon neutral and a renewable energy source that can contribute to sustainable energy supply. The purpose of this study is to develop an optimization model to analyze the rational use of woody biomass fuel in a region from the upstream of forest to the downstream of demand side. The thinning and the installation and operation of equipment are optimized to minimize the total cost over 25 years. The results showed that the behavior of transporting woody biomass and the selection of dehydration place would be influenced by the configuration of energy equipment in demand side. In particular, biomass-based cogeneration systems is expected to be highly effective to utilize woody biomass.

In recent years, with the continuous advancement of renewable resources to replace fossil fuels and the implementation of the FIT system, the large-scale wood-based power plants in Japan has continued to increase. Japan has abundant forest resources, but the wood resources currently used are basically the residual wood in the wood manufacturing plant and the wood produced during construction. In addition, large-scale power stations have appeared obvious shortcomings such as a shortage of wood resources. In order to make more effective use of biomass resources and bring better benefits, it is necessary to re-design the total system as a new solution. In this study, two types of small-scale biomass power plants are compared under certain regional conditions based on system optimization model.

In Hirioshima Scenario, where large suppression of carbon dioxide emission in 2050 is considered, biomass utilization is expected to cover energy use that cannot be supplied by renewable electricity including photovoltaic and wind turbine. Biomass utilization after feed-in tariff should be considered because its cost is still high, and without feed-in tariff, feasibility of the biomass system cannot be assured. Considering that photovoltaic and wind turbine electricity is getting cheaper, power generation from biomass may not be needed. However, electricity from photovoltaic and wind turbine cannot replace fossil fuel use for coke for steel making, jet fuel, and bioplastic. The requirement of the amount of carbon to be supplied to these use and that can be supplied from biomass is compared and discussed.