In this manuscript, to practice the cyclical use of woody resources, which is a typical forest resource, the current state of forest resources using the data in Akita Prefecture and the issues for utilization were discussed from bioeconomy point of view. As a summary briefly, in order to promote the sound maintenance and management of forests and the efficient useof wood resources, it should be necessary to discuss by transcending sc ientific expertise and industrial sectors on three topics; (1) where, how much, and what kind of woody resources are available, (2) how to use them comprehensively without wasting and (3) how to maintain and manage them including ecosystem services. A mult ifaceted approach should be needed to balance the progress in the cyclical use of forest resources as a whole and the sustainable and healthy existence of local societies, rather than for the benefit and development of a particular country or industry.

More than 200 units of biomass compact gasification power generation (CHP) have been installed in Japan since 2016 with the expectation as the regional power source. Nevertheless, there are many cases they don’t work properly. One reason is that the potassium content is different between European and Japanese woods. Potassium can be melted at relatively low temperature (around 800°C) in reducing atomosphere and form clinker which accerelates tar production due to disturbance of homogenious wood gas flow. In past reserches, alumina or talc as anti-clinker additive was added to wood pellet fuels during manufacturing , and they showed a certain effect for improving gasification reaction. However, most of CHPs are fueled with wood chips and how to add the anti-clinker additive should be considered. In this study, we observed the shrinkage of ash sampled in actual CHP fueled with wood chips added 0.4 wt % talc and confirmed the anti-clinker effect.

In Fukushima Prefecture, the number of woody biomass power generation facilities in operation has increased rapidly in recent years, and fuel demand may be strained. In this study, a mail survey was conducted on woody fuel production facilities (N=39) and woody biomass power generation facilities (N=18) in operation as of January 1, 2023, with the aim of understanding the fuel distribution situation. The results indicated that the amount of woody biomass fuel produced in FY2022 was 758,000 tons, but the scale of the project under planning suggests that 220,000 tons will be newly required, which may cause a fuel shortage.

This study estimated the availability of unused materials for woody biomass power generation plants registered in FIT at the end of June 2020 as the supply potential through the introduction of semi-trailers and European-type CTLs. As a result, supply potentials of used and unused materials were estimated at 65,413,601 m³/year and 13,082,720 m³/year, whereas those availabilities were estimated at 64,322,304 m³/year and 12,864,461 m³/year, respectively. Therefore, the rate of the availabilities to the supply potentials was 98.3%. The availabilities of used and unused materials without the introduction were 54,268,941 m³/year and 10,853,788 m³/year. Thus, its introduction contributed to increase the availability. Since the demand of woody biomass power generation plants registered in FIT was estimated at 11,018,104 m³/year, the availability through the introduction met the future demands in Japan as a whole.

This study investigated the effects of heating rates (>50°C/s, 0.7-3.0°C/s and 8°C/min) on the yield and composition of bio-oil in the pyrolysis of Japanese cedar wood chips at 500°C in a fluidised bed or tube furnace. It was observed that the yield of bio-oil increased with increasing heating rates. On the other hand, the calorific value of the bio-oil and the carbon content of the organic components in the bio-oil decreased with increasing heating rates.

Agglomeration formation was investigated in a laboratory-scale fluidized bed test apparatus by preparing ash simulating the biomass fuel from reagents. When silica sand was used as the fluidizing medium, depending on the conditions of temperature and the amount of simulated ash input, fluidization ceased after ash addition and agglomeration of the fluidizing medium was observed after cooling. .It was observed that agglomeration was reduced when artificial sand was used as the flow medium.

Napier grass, which is classified as an herbaceous biomass, was used in Japan as a grass and fodder, but its high nitrogen utilization efficiency, vigorous growth under poor nutritional conditions, and huge stem and leaf dry matter yield have raised expectations for its use as a possible biomass energy resource. Analysis of the inorganic elements contained in Ngrass reveals that it contains a large amount of potassium, an alkali metal, which always acts as a catalyst and accelerates gas production. In this study, we examined the conditions for the gasification of Napier grass to produce hydrogen-rich syngas.

While Japan is among the top countries with the most forests, 2/3 of Japan areas are covered with wood forests, the thermal utilization business of biomassfuels is very poor in comparison with several European countries. Japan has been relied on fossil petroleum fuels for thermal and electrical utilization for long time. Even though, Prime Minister, Mr. Suga declared Japan has set itself Zero Carbon by 2050, it is not easy way to achieve this target. We, NPO Nouto Conference, has established Biomass Academy to enhance the thermal utilization business with biomassfuels in 2018. In this paper, we will discuss current Japan’s status of Biomass Renewable Energy Business in comparison with Europe and Asia, and the Best Practice activities for dramatic expansion of Biomass Boilers in Japan.

Acidic groups such as carboxylic and phenolic groups are associated with the physicochemical properties of biochar as a soil amendment. Generally, the Boehm method has been used for the measurement of acidic groups, but due to the use of titration, a large amount of biochar is required for the measurement. To study the evolution of these acidic groups in char in more detail, a smaller scale method is desirable. Also, alkali and alkaline earth metal cations in wood may interfere with accurate determination. In this paper, we propose a small-scale modified Boehm method using ash content measurement instead of titration. Influences of pyrolysis temperature (400-1000°C) on the development of carboxylic and phenolic groups were also studied for the carbonization of Japanese cedar (Cryptomeria japonica, Sugi) and its Klason lignin and cellulose (Avicel).

The pyrolysis reaction of hemicellulose was analyzed by reactive molecular dynamics (ReaxFF-MD) simulation. Four molecular models of hemicelluloses were used: O-Acetyl-galactoglucomannan and Arabino-4-O-metylglucuronoxylan from softwood, and O-Acetyl-4-O-methylglucuronoxylan and Glucomannan from hardwood. From the atomic trajectories obtained by simulation, the pyrolysis behavior and detailed chemical species of the four hemicelluloses were evaluated. As pyrolysis products of hemicellulose, chemical species mainly classified as linear alcohols, linear ketones and aldehydes were observed.

In Lake Tana, Ethiopia, there is an overgrowth of water hyacinth, causing problems such as ecological disruption and hindrance to navigation by boats. Furthermore, the increasing reliance on fuelwood and charcoal production has led to deforestation. To address these issues, use of charcoal briquette using biochar derived from water hyacinth as an alternative fuel source has been recently evaluated. However, the combustion of charcoal briquette for fuel may pose risks of indoor air pollution, potentially leading to health issues. Therefore, the objective of this study was to measure and assess the concentrations of CO, CO₂, and NOx during the combustion of water hyacinth-derived charcoal briquette.

Currently, carbon-neutral biomass fuels are attracting attention as an alternative fuel to fossil fuels from the perspective of combating global warming and realizing a sustainable society. However, biomass fuels have the problems of low energy density and high transportation costs. Therefore, we focused on biomass gasification technology. In this study, H₂O gasification experiments were conducted with four different grain size samples using an electrically heated vertical batch furnace to investigate the effect of char grain size on the H₂O gasification behavior of woody biomass char. As a result, there was almost no effect of char particle size on the reaction rate because the reaction proceeds by diffusion of the gasifier into the porous structure of the wood.

Toward a decarbonized society, biomass energy is promising in terms of weather-independence and adjustable output. In this study, the effects of various calcium compounds added to Japanese cedar (JC) on the yield and composition of produced gases and kinetic parameters in the JC carbonization process were evaluated to investigate the mechanism of increase in H₂ production by eggshell (ES) addition. Addition of ES, CaCO₃ and CaO to JC, increased H₂ and CO production, and decreased CO₂ production in all cases. The results also that the addition of ES to JC increased the activation energy of pyrolysis above 600°C.

Smallwood biomass CHP, combined with wood chip boiler, is much expected as fitsolution for replacing fuel oil consumption at commercial facilities incountryside Japan. However, wood gasification is notorious for its demand on O&Mexpertise and efforts from user. To date only small fraction of users reachstable operation and satisfactory utilization rate. With this article Authorbegins to share experiences of daunting series of random problems during early yearsof operation. Author invites discussion for improvements toward much easier useof Wood CHP in future.

In our previous study, 5-hydroxymethylfurfural (5-HMF) was proposed as a key intermediate in cellulose carbonization. In this study, the formation mechanism of benzene rings in cellulose char was investigated by using ¹³C-labeled 5-HMFs and ¹³C-labeled glucoses. Char fraction obtained from the labeled 5-HMFs with glycerol (a model of coexisting primary pyrolysis products of cellulose) or labeled glucoses were analyzed by pyrolysis gas chromatography / mass spectrometry (Py-GC/MS). Based on the ¹³C content of fragments, the carbonization pathways are proposed, including furan rings partially remaining in the char, direct rearrangement of 5-HMF to phenols, and construction of benzene rings by condensation of the ring-opening fragments of 5-HMF. Based on these results, the mechanism of the char formation from cellulose during pyrolysis is discussed.

In Japan, theabsence of quality standards for woody biomass fuels (chips and pellets) hascaused fluctuations in fuel quality. This has hindered the efficient operationof power plants and heat utilization facilities. In this study we observed outof the 36 sample ashes, 23 expanded and foamed between 650 and 900°C in both CO₂ andreducing atmosphere. Since ash species with high potassium content areprevalent throughout the country, it is essential to consider ashcharacteristics when developing applications for woody biomass.

In recent years, the primary energy consumption has been incresing globally. Demands for biomass fuels, which are carbon neutral, have been becoming larger. However, biomass fuels have problems such as low energy density and low transportation efficiency. To solve them, biomass gasification has gained broad attention. In this study, we investigated the effect of CO₂ as an oxidant in the gasification reaction of woody biomass. CO₂ gasification experiments were conducted under three conditions with different CO₂ concentrations using an electrically heated drop tube furnace, and the produced gas was analyzed for chemical compositions. As a result, it was found that CO production increased with increase in CO₂ concentration under the experimental conditions while H₂ production decreased.

Overgrowth of water hyacinth (WH) poses environmental and economic challenges. This study explores the potential of utilizing WH biomass as solid fuel through hydrothermal carbonization (HTC). HTC converts high-moisture organic waste into biochar and bio-oil. While increasing the temperature during HTC improves bio-oil yield, it reduces energy recovery. Mixing WH with other biomass and adding citric acid enhances the process, particularly in bio-oil yield and energy recovery. The research revealed that citric acid enhanced bio-oil yield and energy recovery, indicating its role in promoting synergistic reactions in co-biomass hydrothermal carbonization.

Small-scale wood gasification combined heat and power plants, which are promising for realising a decarbonised society and local revitalisation, have a low operation rate in Japan, partly due to the generation of clinker from the inorganic components of wood fuels, particularly cedar. In previous studies, although additives for clinker suppression were investigated, reducing the cost of additives was a challenge. The authors therefore considered that the clinker suppression effect could be achieved by appropriately blending cedar parts in the raw material instead of additives, and investigated blending sapwood and bark with the black heartwood of cedar. However, it was unclear whether the blending of sapwood or bark was effective for red heartwood. This study clarified the effect of binary blend of sapwood, heartwood, and bark on the ash fusion temperature for red heartwood of cedar and to identify the blend conditions to improve the fusion temperature.

We have been developing the on-site methane fermentation system for the purpose of recovering energy from kitchen waste and kitchen wastewater. In the previous system, about 30% of the organic matter contained in kitchen waste and kitchen wastewater was treated by wastewater treatment equipment. Therefore, we focused on the low temperature UASB as a method for recovering energy from organic matter in wastewater. In this study, we conducted continuous tests on the low temperature UASB using kitchen wastewater collected from an operating commercial building, and report the results.

This study aims to establish the hybrid methods using the closed and open microalgal cultivation systems for stable production of the biomass of marine diatoms Fistulifera solaris JPCC DA580 and Mayamaea sp. JPCC CTDA0820. We will improve the productivity of the diatom biomass by employing a wide range of techniques including more efficient utilization of solar energy, elucidation of the bottleneck of photosynthesis and oil production metabolism.

HyGeiaA, a small on-site hydrogen production device, produces hydrogen from city gas and emits flue gas containing CO₂ as a byproduct. If the flue gas that is normally exhausted into the air can be used for the growth of microalgae, the cultivation of microalgae may become an effective means of CCU. We developed a glass tube photobioreactor (PBR) installed outdoors that can supplied flue gas and evaluated the performance. As a result, two types of microalgae could be cultured. It was also found that CO₂ usage efficiency could be improved by modifying the gas supply section. In the future, we plan to measure the amount of CO₂ absorption and fixation rate in detail, and design an expanded model for industrialization.

Ferrierite zeolites were investigated as catalysts for the dimethyl ether (DME)-to-olefin (DTO) reactions to efficiently synthesize n-butene, such as 1-butene, trans-2-butene, and cis-2-butene using a fixed-bed flow reactor. P-loaded ferrierite zeolites with different structural parameters and acidic properties were prepared by the impregnation method by varying the P content and the temperature of air calcination as a pretreatment. Micropore surface area, external surface area, total pore volume, micropore volume, and weak and strong acid sites affected the DTO reaction behavior. A high n-butene yield (31.2 C-mol%) was observed, which is higher than the previously reported maximum yield (27.6 C-mol%).

Pyrolysis-based saccharification of pulp has attracted attention because pyrolysis of pulp yields levoglucosan, an anhydrous sugar. Alkali (Na⁺, K⁺) and alkaline earth (Mg²⁺, Ca²⁺) metal cations, present as cation-exchangeable salts of carboxyl groups in pulp, have a significant effect on the pyrolysis of cellulose in pulp. In this study, pulp exchanged with each metal cation was analyzed by thermogravimetry-mass spectrometry (TG-MS) to investigate the mechanism of their effects. The results obtained provide valuable insights for the production of levoglucosan by pulp pyrolysis.

High-temperature and high-pressure water has been recognized as a green chemical medium for monosaccharide reactions because dehydration and/or retro-aldol condensation can proceed without the use of a catalyst. There are some reports on the monosaccharides containing the hydroxyl groups (-OH) such as glucose and fructose. We previously reported the reaction of N-acetyl glucosamine, which contains an acetoamide group (-NHCOCH₃). In this work, we investigated the reaction of sialic acid and fucose, which are monosaccharides; however, there is no report on these two monosaccharides previously. Sialic acid contains both an acetoamide group (-NHCOCH₃) and a carboxyl group (-COOH). Fucose contains a methyl group (-CH₃). The dehydrations of sialic acid and fucose were proceeded in high-temperature and high-pressure water. In addition, the chemical structures of the dehydration products were affected by the functional group contained in sialic acid and fucose.

Levulinic acid is one of the platform chemicals synthesized from cellulose with the generation of formic acid. Succinic acid, which can be synthesized from levulinic acid by Baeyer–Villiger oxidation, is also one of the platform chemicals. Succinic acid is a versatile substance with a wide range of applications. In this study, we investigated the reactivity of levulinic acid-succinic acid reaction with performic acid, obtained from formic acid and H₂O₂. The yield of succinic acid was 3.76% after 180 min at 90 °C. Most of the formic acid and H₂O₂ were decomposed immediately after the start of the reaction, and the yields of the various products converged accordingly. This result suggested the concentrations of formic acid and H₂O₂ have a significant effect on succinic acid synthesis.

Lignin is the most abundant natural aromatic polymer, and its quantitative and qualitative modification by genetic engineering is attracting attention towards its efficient conversion into value-added materials. In this study, the feruloyl-CoA 6'-hydroxylase gene (F6'H1) from Arabidopsis thaliana was overproduced in hybrid aspen to modify the lignin luminescence properties by the incorporation of scopoletin into lignin molecule. Cellulolytic enzyme lignin (CEL) was isolated from the transgenic aspens with various F6'H1-overproduced levels and evaluated for luminescence properties. Analysis of photoluminescence (PL) spectra of CEL in DMSO solutions showed high PL intensity with longer wavelengths in the F6'H1-overproduced aspen. The structure and distribution of the major chromophore, scopoletin, was discussed based on the spectral analysis in low-polarity solvents and structural analysis using gel permeation chromatography with a fluorescence detector. Furthermore, a reversible photodimerization reaction, characteristic of coumarins, was observed in F6'H1-overproduced aspen. These results suggest the great potential of genetic engineering strategy of the incorporation of scopoletin into lignin to produce the value-added materials.

We have developed equipment that dries the residue produced when extracting coffee (hereafter referred to as "coffee grounds") using a drying machine, processes it into solid fuel using a pellet molding machine, and roasts coffee using these pellets as fuel in a roasting machine (hereafter, the "green roasting machine"). Traditionally, coffee grounds have been disposed of as industrial waste in most beverage extraction facilities, incurring significant costs. Moreover, the roasting of coffee has typically relied on fossil fuels, leading to substantial greenhouse gas (GHG) emissions.Through this innovation, we can not only reduce the disposal cost associated with coffee grounds but also achieve a reduction in GHG emissions. Through this initiative, we aim to set a standard for sustainable practices in the coffee industry and position coffee as a model case for the Sustainable Development Goals (SDGs) in the food sector.

To estimate trunk volume and be visualization inside forest, supplemental software tools were developed for segmentation of tree components and measurement of size parameters by using of the latest machine learning for 3D point cloud. Point cloud of two plantation forests obtained in Fukushima Prefecture was preprocessed by the developed remote sensing tool of forest (las2tree) and manual segmentation separating into tree trunk and other components.Customized PointNet++ performed automatic segmentation for tree components. Accuracy of the segmentation was favorable for the future forest modeling process.

In recent years, Water hyacinth (Eichhornia crassipes) has been overgrowing all over the world, adversely affecting lake ecosystems and the people living in the vicinity. The objective of this study was to evaluate the effective use of water hyacinth for fuel and soil amendment application through life cycle assessment. System boundaries were defined as raw material procurement, transportation, biochar making, and fuel and soil amendment applications. The functional unit was defined as per kilogram of water hyacinth. The results suggested that the use of soil amendments was an effective way to utilize water hyacinth.

The utilization of woody biomass in Tochigi Prefecture、Japan was evaluated from the perspectives of economic efficiency and environmental impact. As a result, it was clarified that (1) the carbon dioxide emissions for lumber production were approximately 10% of the amount of carbon fixed in the product. (2) it has approximately 4% of the cost reduction effect on material usage utilizing lumber scraps for energy and 10% of it utilizing forest residues for energy. Based on the above results, it is expected that the integrated use of woody biomass for material and energy use will expand its utilization and promote low-carbonization with economic rationality.

Shortage of phosphate ore used in fertilizers and industry is a worldwide problem. On the other hand, excessive residual phosphate in closed water areas, such as lakes and marshes, causes eutrophication problems, resulting in too many nutrients in seawater and river water than in natural conditions. Based on the current situation, we guess that developing a method to recover phosphate from closed water areas could solve the environment, the resources, and the food problems. This study aims to investigate the mechanical system for efficient phosphate recovery in terms of eco-design. The dynamic performance is estimated regarding recovering calcium phosphate using the basic experimental apparatus. Here, the sorbent as calcium carbonate in modeled agricultural water was used. Through our tests, we found that about 90% of phosphorus in closed water areas in 4 min would be recovered. Finally, based on the experimental results, we estimated the eco-burden during the operating performance based on the LCA methodology. Consequently, approximately 66% against the conventional achieve CO₂ mitigation.

This study proposes a new method for estimating tree diameter at breast height (DBH) using 3D point cloud data for sustainable forest resource management. The research focuses on forest resource management in Japan, and a circle fitting program using the RANSAC algorithm has been developed to tolerate outliers and improve accuracy. However, improving automation is considered a future challenge.

We are focusing on biomass pyrolysis as a green hydrogen production method, increasing the hydrogen demand in recent years. One of the challenges of this process is the tar generated during pyrolysis. If tar condenses and adheres to pipes or furnace walls, it can inhibit heat exchange and clog pipes. We argued tar removal conditions on the temperatures in the pyrolysis and the reforming processes in this study as tar removal conditions. Biomass-derived tar is composed mainly of cellulose and lignin. Therefore, to estimate the tar decomposition rate, we conducted experiments on the pyrolysis of cellulose and lignin with heating rates and reaction temperatures as parameters. Note that the measurement was implemented using the thermogravimetric analyzer and the online gas detector. The deviation between the experimental and practical plant results would be caused due to the differences in operating conditions. The temperature distribution may not be uniform so the tar decomposition rate may vary depending on the location in the furnace. Therefore, based on the experimental results, we used CFD simulations to analyze the tar decomposition behavior when extended from the experimental in the laboratory to the plant scale.

We have devised a system that efficiently generates electricity by mixing oxygen obtained from hydrogen production with air and using it as a gasifying agent for woody biomass. In order to put this system into practical use, we conducted a simulation to clarify the effect that the oxygen concentration of the gasifying agent has on the system.

To remove tar produced in the pyrolysis and gasification of bio-waste, we are studying on tar removal using not Ni catalysts or activated coal but residues such as char and ash accumulating on the bottom of pyrolyzer and gasifier. In the study, benzene vapor as simulated tar and N₂ gas were supplied to fixed bed of residues after pyrolysis and gasification of bio-waste, followed by heating the fixed bed to 450°C. Benzene removal rates using each bio-waste were examined by comparing benzene concentration in flue gas with that in blank test.

We are trying to introduce renewable hydrogen into steam gasification of woody biomass in order to reduce CO₂ emission from Biomass-to-Liquids (BTL) process. In the study, the effect of the addition of hydrogen to the steam gasification of woody biomass on the product gas composition was investigated using a fixed-bed continuous wood-supplying reactor. As a result, the introduction of hydrogen into the gasification at 900°C inhibited CO₂ production, while also inhibiting the conversion of carbon in woody biomass to product gas.

It was found that by adding CaO or K₂CO₃ to PVC at a molar ratio of 3 during pyrolysis at 573K, the hydrogen chloride generation rate could be reduced from 75% to 20%. On the other hand, when CaCO₃ was added at the same molar ratio, the hydrogen chloride generation rate could only be reduced to about 60%. Further, when K₂CO₃ was added at a molar ratio of 1, the amount of hydrogen chloride contained in the solid residue was about 50%.

Fluidized bed combustion equipment for biomass has not been widely adopted by Small and Medium Business（SMB）because of its largeness. Therefore, we aim to downsize the fluidized bed and to simplify the ancillary equipment by reducing the air ratio during combustion in this study. To achieve this objective, we evaluated the effects of differences in the internal structure of the combustor on combustion characteristic. We investigated carbon conversion rate and carbon dioxide conversion rate based on the presence or absence of secondary air and freeboard fluidized bed. As a result, it was confirmed that the inflow of secondary air promoted the combustion of unburned samples and unburned gas, and the fluidized bed in the freeboard section promoted the combustion of unburned samples.

In conventional Fischer-Tropsch synthesis (FTS), Fe-based catalyst is used for higher olefin selectivity. We are trying to use Fe-based catalyst for higher paraffin selectivity in FTS in order to achieve lower cost and earlier practical realization of Biomass-to-Liquids (BTL) process. In the study, the effect of FTS condition on CO conversion and hydrocarbon selectivity was experimentally examined. In addition, the effect of promotor supported with Fe-based catalyst on FTS was also examined.

In this study, the effect of carbonization temperatures of cedar char on the saccharification performance of cellulase recovered using cedar char was evaluated by kinetic analysis. Cellulase recovered using cedar char showed higher substrate affinity than free cellulase. The elution amount of cellulase tended to increase with increase of substrate concentration.

In methane fermentation using high nitrogen-concentrated feedstock, inhibition by ammonia is a problem. This study aimed to reduce the amount of free ammonia and suppress inhibition by adjusting the pH in the fermenter to 6.8 to 7.3 by adding acid. Results showed that pH control by acid addition was possible and had no adverse effect on methane fermentation. In addition, even at high nitrogen concentrations with TAN of 9,000 to 11,000 mg L^-1, it was possible to suppress ammonia inhibition and maintain methane production through pH control. These results suggest that methane fermentation using high nitrogen-concentrated feedstock, which has been difficult to achieve in the past, is possible, and that a high nitrogen-concentrated digestate can be obtained as a result.

In this study, the pelletizing characteristics and quality of a new material made from a mixture of cattle manure compost and biochar were revealed using a roll-type flat die pelletizer, which is used for fertilizer production and wood pellets. The 25% biochar mixing rate decreased the bulk density of the raw material, resulting in a lower production volume compared to cattle manure compost alone, but the energy intensity, which indicates energy input per production volume, was maintained at the same level. In terms of quality, the 25% biochar blending rate showed equal or better durability and wettability, indicating that it can be used in the same way as cattle manure compost pellets for fertilizer.

In this study, acetylated woody flour was prepared by acetylating pulverization using a vibration mill with ring media, mixed with ABS, and formed into filament for fused additive manufacturing 3D printer. The tensile strength of filaments mixed with 15wt% acetylated wood flour reached over 23MPa. It was also confirmed that the variation in tensile strength was suppressed by using particles with a particle size of 100-250μm.

Polymethyl methacrylate (PMMA) resin is widely used as a material with excellent hardness, weather resistance, and transparency, but its physical strength is lower than other resins. On the other hand, there is a social demand for de-plasticization and plastic reduction. In this study, cellulosic materials including CNF were used as reinforcement for PMMA resin to improve the functionality of PMMA resin and to reduce the amount of plastic used by using plant resources, and the kneading conditions were investigated together with various additives.

In this study, wood flour acetylation with paratoluenesulfonic acid as a catalyst was carried out using a vibration mill with ring media with increasing amounts of acetic anhydride. As a result, it was confirmed that wood flour with a high acetylation degree was obtained by increasing the amount of acetic anhydride added, but the acetylation reaction rate tended to slow down.

A simultaneous pulverization and acetylation of wood powder (Japanese cedar) was carried out using a vibration mill with ring media to imparts functionality to wood. Acetic anhydride was used as the acetylation reagent to be added during pulverization, and the input ratio of acetic anhydride was set to 50% for 800 g wood powder. The degree of acetylation by the weight percent gain (WPG) were estimated using saponification of the pulverized sample. And the particle size distribution and heat resistance by thermogravimetry was measured. As a result, acetylation reaction was finished in a short milling time of 15 minutes, and WPG of acetylated wood powder was reached 15.0%. In addition, the 95% weight loss temperature of the powder was improved by 14 °C.

For the direct hydrogenation of succinic acid (SA), 1,4-dioxane derived from fossil resources has been widely used as a solvent. In this study, we aim to establish a reaction system for γ-butyrolactone (GBL) production by SA hydrogenation by using biomass-derived tetrahydrofuran (THF) solvent. We compared GBL yields at different reaction temperatures, reaction times, and hydrogen pressures. The results show that higher reaction temperature up to 230 ºC was superior to GBL yields. From the comparison of reaction time, it was found that the rate-limiting step in the SA–GBL reaction is the reaction of the intermediate succinic anhydride to GBL, and that the GBL yield decreases after a certain reaction time due to GBL overreaction. Hydrogen pressure had a significant effect on GBL yield. These experiments showed high GBL yield of up to 52.3mol% (230 °C, 6 h, 3 MPa) by using a biomass–derived THF solvent.