Japanese Cedar Bark Research Articles

Supercapacitors composed of Japanese cedar bark-based activated carbons with various activators

This study provided an overview of how pore structures and functional groups influence the electrochemical behaviors of activated carbons derived from a new type of biomass waste - Japanese cedar bark (JCB) with four different activators, i.e., KOH, K2CO3, H3PO4, and ZnCl2. Based on the chemical composition, microstructure, gas adsorption isotherms, and electrochemical analytical techniques, relationships between the pore structures, functional groups, and electrochemical behavior of the activated samples were assessed. The K2CO3 and KOH activated materials, designated KC-6 and KO-6, respectively, with an activation ratio of 6 (6 g an activator/1 g of JCB), were well rated for their electrochemical capabilities. At 10 mA g−1, these two samples had a specific capacitance of roughly 210 F g−1. The high electrochemical potential of KC-6 was attributed to a particular hierarchical structure comprised of micro-meso-macropores and rich oxygen functional groups on its surface, allowing faster ion diffusion and more effective ion adsorptions. Furthermore, in the case of the 1 M H2SO4 electrolyte, KO-6 had the largest specific surface area of 3000 cm2 g−1 and appropriate micropores (diameters (d) < 1.2 nm) for the electrolyte ion adsorptions, thus allowing this model to maintain an 80% specific capacitance for approximately 6500 Cyclic Voltammetry cycles at 1 mV s−1. The pore properties, functional groups, and electrochemical properties of the activated material derived from JCB can be controlled to some extent by the activator selections and experimental conditions.

Radiocesium mobility in different parts of the two major tree species in Fukushima

Radiocesium (137Cs) released in the Fukushima Dai-ichi Nuclear Power Plant accident is still cycling in the forest ecosystem. We examined the mobility of 137Cs in the external parts—leaves/needles, branches, and bark—of the two major tree species in Fukushima, Japanese cedar (Cryptomeria japonica) and konara oak (Quercus serrata). This variable mobility will likely lead to spatial heterogeneity of 137Cs and difficulty in predicting its dynamics for decades. We conducted leaching experiments on these samples by using ultrapure water and ammonium acetate. In Japanese cedar, the 137Cs percentage leached from current-year needles was 26–45% (ultrapure water) and 27–60% (ammonium acetate)—similar to those from old needles and branches. In konara oak, the 137Cs percentage leached from leaves was 47–72% (ultrapure water) and 70–100% (ammonium acetate)—comparable to those from current-year and old branches. Relatively poor 137Cs mobility was observed in the outer bark of Japanese cedar and in organic layer samples from both species. Comparison of the results from corresponding parts revealed greater 137Cs mobility in konara oak than in Japanese cedar. We suggest that more active cycling of 137Cs occurs in konara oak.

Hydrothermal separation of lignin from bark of Japanese cedar

Hydrothermal treatment was used to study the separation of lignin from bark derived from biomass. A coupled-system of two batch reactors was used to treat Japanese cedar bark (ca. 45% lignin) with water at 473K–573K without additives and to collect lignin fractions at given times. Hydrothermal treatment of bark at a temperature of 548K and a treatment time of 10min allowed 65wt% of the lignin to be separated, which means that it is possible to obtain about 0.3kg-lignin per kilogram of Japanese cedar bark. From the characterization, it was revealed that the hydrothermal-soluble lignin had a simple structure with a molecular mass of about 1000Da. The yield of lignin decreased for treatment temperatures higher than 548K that is attributed to carbonization. Hydrothermal treatment of bark can be used to recover lignin and has potential application to biorefineries.

3-1-1 スギ樹皮の連続ガス化におけるCa(OH)2の添加効果(3-1 ガス化1,Session 3 バイオマス等,研究発表)

3-1-1 スギ樹皮の連続ガス化におけるCa(OH)2の添加効果(3-1 ガス化1,Session 3 バイオマス等,研究発表)

P226 木材構成成分のガス化特性 : 小型噴流床ガス化炉における樹皮,脱リグニン樹皮ペレットのガス化(ポスター発表)

P226 木材構成成分のガス化特性 : 小型噴流床ガス化炉における樹皮,脱リグニン樹皮ペレットのガス化(ポスター発表)

Cesium absorption through bark of Japanese cedar (Cryptomeria japonica)

Absorption of radiocesium (137Cs and 134Cs) through bark, and its subsequent translocation into wood and needles, has been suggested as a potential source of tree contamination, but the process is not well understood. Field experiments were conducted to confirm whether Cs could enter a Japanese cedar tree through the bark and how Cs moves within a tree. Stable Cs (133Cs) was applied to the bark at 1.2-m height on 10- and 26-year-old Japanese cedars. The 133Cs concentrations were determined in the bark, sapwood, and heartwood (for 26-year-old cedar only) of stem disks from several heights, as well as in current-year needles from the canopy. The 133Cs concentrations were considerably higher in the sapwood and heartwood of stem disks from 1.2-m height in treated trees than in untreated trees, suggesting that 133Cs penetrated the bark to enter the wood. The average 133Cs concentrations were higher in the heartwood than the sapwood, indicating 133Cs accumulation in the heartwood. High 133Cs concentrations in the needles of treated trees implied acropetal movement of 133Cs to actively growing organs. Our results demonstrate that Cs can enter Japanese cedar trees through the bark and that Cs is transported radially to the heartwood and vertically to the apex.

Why do small Japanese flying squirrels, Pteromys momonga, prefer Japanese cedar bark as a nest material ? II. Study of heat-trapping capacity

Why do small Japanese flying squirrels, <i>Pteromys momonga</i>, prefer Japanese cedar bark as a nest material ? II. Study of heat-trapping capacity

Radiocesium concentrations in the bark, sapwood and heartwood of three tree species collected at Fukushima forests half a year after the Fukushima Dai-ichi nuclear accident

Radiocesium (134Cs and 137Cs) distribution in tree stems of Japanese cedar (aged 40–56 y), red pine (42 y), and oak (42 y) grown in Fukushima Prefecture were investigated approximately half a year after the Fukushima Dai-ichi nuclear accident. Japanese cedar, red pine, and oak were selected from five sites, one site, and one site, respectively. Three trees at each site were felled, and bark, sapwood (the outer layer of wood in the stem), and heartwood (the inner layer of wood in the stem) separately collected to study radiocesium concentrations measured by gamma-ray spectrometry. The radiocesium deposition densities at the five sites were within the range of 16–1020 kBq m−2. The radiocesium was distributed in bark, sapwood, and heartwood in three tree species, indicating that very rapid translocation of radiocesium into the wood. The concentration of radiocesium in oak (deciduous angiosperm) bark was higher than that in the bark of Japanese cedar and red pine (evergreen gymnosperms). Both sapwood and heartwood contained radiocesium, and the values were much lower than that in the bark samples. The results suggest that radiocesium contamination half a year after the accident was mainly attributable to the direct radioactive deposition. The radiocesium concentrations in the Japanese cedar samples taken from five sites rose with the density of radiocesium accumulation on the ground surface. To predict the future dynamics of radiocesium in tree stems, the present results taken half a year after the accident are important, and continuous study of radiocesium in tree stems is necessary.

No.46 スギ樹皮の低中温熱分解に及ぼす水蒸気の影響(バイオマス(1))

No.46 スギ樹皮の低中温熱分解に及ぼす水蒸気の影響(バイオマス(1))

Why do small Japanese fl ying squirrels, Pteromys momonga, prefer to use bark of Japanese cedar as a nest material?

Why do small Japanese fl ying squirrels, <i>Pteromys momonga</i>, prefer to use bark of Japanese cedar as a nest material?

I214 稲ワラと杉バークの急速熱分解特性(OS-11: バイオマス関連の基礎研究と利活用(1))

I214 稲ワラと杉バークの急速熱分解特性(OS-11: バイオマス関連の基礎研究と利活用(1))

Gasification reaction kinetics on biomass char obtained as a by-product of gasification in an entrained-flow gasifier with steam and oxygen at 900–1000 °C

The purpose of this study was to investigate the gasification kinetics of biomass char, such as the wood portion of Japanese cedar char (JC), Japanese cedar bark char (JB), a mixture of hardwood char (MH) and Japanese lawngrass char (JL), each of which was obtained as a by-product of gasification in an entrained-flow type gasifier with steam and oxygen at 900–1000 °C. Biomass char was gasified in a drop tube furnace (DTF), in which gasification conditions such as temperature ( T g), gasifying agent (CO 2 or H 2O), and its partial pressure ( P g) were controlled over a wide range, with accompanying measurement of gasification properties such as gasification reaction ratio ( X), gasification reaction rate ( R g), change of particle size and change of surface area. Surfaces were also observed with a scanning electric microscope (SEM). By analyzing various relationships, we concluded that the random pore model was the most suitable for the biomass char gasification reaction because of surface porosity, constant particle size and specific surface area profile, as well as the coincidence of R g, as experimentally obtained from Arrhenius expression, and the value is calculated using the random pore model. The order of R g was from 10 −2 to 10 −1 s −1, when T g = 1000 °C and P g = 0.05 MPa, and was proportional to the power of P g in the range of 0.2–0.22 regardless of gasifying agent. Reactivity order was MH > JC > (JB, JL) and was roughly dependent on the concentration of alkali metals in biomass feedstock ash and the O/C (the molar ratio of oxygen to carbon) in biomass char.

3-8 水蒸気/酸素雰囲気下でのスギ樹皮,脱リグニン樹皮のTG測定とガス化特性の考察((2)ガス化2,Session 3 バイオマス等,研究発表(口頭発表))

3-8 水蒸気/酸素雰囲気下でのスギ樹皮,脱リグニン樹皮のTG測定とガス化特性の考察((2)ガス化2,Session 3 バイオマス等,研究発表(口頭発表))

Biomethanol Production and CO2 Emission Reduction from Forage Grasses, Trees, and Crop Residues

With a wide array of potentially renewable energy resources, the concept and proposed benefits evolving from the use of biofuels are inspiring. Recently, a new approach for gasification of biomass by partial oxidation and subsequent biomethanol production has been developed and is being evaluated at the “Norin Green No. 1 (renamed as Norin Biomass No. 1)” test plant in Nagasaki, Japan. To determine a useful protocol for producing biomethanol, various kinds of biomass resources, such as sawdust and bark of Japanese cedar, chipped Japanese larch, bamboo, salix, cut waste wood from demolition sites, sorghum, and bran, straw, and husks of rice were evaluated for their biofuel-use characteristics. From this analysis, lignocellulosic resources (wood materials) and rice bran were estimated to produce a high methanol yield (55% by weight), whereas rice straw and husks were estimated to produce lower methanol yield of 36% and 39%, respectively. On the basis of the data obtained from the test plant, the net heat yield by the methanol production of a full-scale commercial plant was estimated to be ca. 40%. Each of these products is a clean material, readily obtained and highly useful for biomethanol production. Developing nations interested in constructing a national energy policy should focus upon the establishment of a biofuel-based economy. Recycling of agricultural and forest industry by-products has been previously shown to reduce the demand for fossil fuels and provides a more ecologically friendly energy resource. Our research suggests that additional sources of biomethanol production could be developed through the utilization of cellulosic and lignocellulosic raw materials.

Biosorption of Cr(VI) on Japanese Cedar Bark

The ability of Japanese cedar (Cryptomeria japonica) bark to remove Cr(VI) from aqueous solutions was investigated. The research parameters included the solution pH, temperature, and initial concentration of Cr(VI) in solution. The removal of Cr(VI) was highly solution pH dependent and adsorbate concentration dependent, and mainly governed by physicochemical adsorption under the weak acidic conditions studied (initial solution pH ≥ 3). However, the reduction of Cr(VI) to Cr(III) occurred extensively at low solution pH (initial solution pH ≤ 2). The equilibrium data at different temperatures fit well in the Langmuir isotherm model. The endothermic nature of the adsorption was confirmed by the positive value of enthalpy change (18.9 kJ mol−1). The positive value of entropy change (65.2 J mol−1 K−1) suggested the increased randomness at the solid–solution interface during the adsorption. The studies showed that Japanese cedar bark can be used as a cost‐effective adsorbent for the removal of Cr(VI) from wastewater.

Optimization of Thermal Preprocessing for Efficient Combustion of Woody Biomass

We attempted to optimize both drying time and temperature for stem chips and bark of Japanese cedar in order to obtain the largest release of combustion heat. Moisture release rates of the stem and bark during air-drying in an oven were evaluated. Higher and lower heating values of stem and bark, dried at different temperatures for different lengths of time, were also evaluated. The drying conditions of 180°C and 30min resulted in the largest heat release of the stem (∼ 4%increase compared to conditions of 105°C and 30min). The optimal drying conditions were not obvious for bark. However, for the drying process in actual plants, the conditions of 180°C and 30min were suggested to be acceptable for both stem and bark.

スギ樹皮の熱分解物と活性炭の細孔特性

スギ樹皮の熱分解物と活性炭の細孔特性

Removal of trichloroethylene from aqueous solution by pyrolyzed Japanese cedar bark

The bark of Japanese cedar (Cryptomeria japonica D. Don) was heated in an N2 atmosphere at 300‡–900‡C for 3h to investigate the surface properties of the pyrolyzed residuces and their ability to remove trichloroethylene (TCE) from aqueous solutions. The specific surface areas (S N) and total pore volumes (V N) of the pyrolyzed barks steadily increased with rising pyrolysis temperature; no significant differences in the average pore diameters (D N) were observed at higher temperatures (600‡–900‡C). The adsorption capacities of the pyrolyzed residues for TCE were determined under batch mode conditions using an aqueous solution containing 500Μg TCE dm−3. The adsorption data were well fitted to the Freundlich equation. The adsorption capacity of the bark pyrolyzed at 900‡C was about five times larger than that of commercial activated carbon.

Effects of Japanese Cedar Inner Bark Nutritional Quality on Development of Semanotus japonicus (Coleoptera: Cerambycidae)

The inner bark of Japanese cedar, Cryptomeria japonica D. Don., is the main food of the bark borer Semanotus japonicus Lacordaire. Borer adults that emerge from dead trees are usually smaller than those from living trees, suggesting that nutritional quality of the host material affects the development of S. japonicus . To evaluate the influence of the nutritional quality of cedar inner bark on borer development and survival, I introduced newly hatched larvae into cedar logs that were waxed, unwaxed with 1 end in water, or into control logs that were unwaxed and not watered. In the watered logs, larval and adult weights were greater than those of adults from waxed logs and control logs. Nitrogen content, an index of nutritional quality, and water content in watered logs, were significantly higher than those in waxed logs and control logs 40 d after larval introduction. These results suggest that enhanced nutritional conditions in the inner bark of logs can positively affect borer development.

Reproductive strategy of the sugi bark borer, Semanotus japonicus (Coleoptera: Cerambycidae) on Japanese cedar, Cryptomeria japonica

The inner bark of Japanese cedar,Cryptomeria japonica D. Don., is the main food of the sugi bark borer,Semanotus japonicus Lacordaire, but may also be involved in resistance to attack by the borer. I used newly hatched larvae to inoculate cedar logs that had been cut 2-weeks to 12-months earlier, and undamaged living cedar trees. On living trees, all larvae were killed by resin flow from the traumatic resin canals between the outer- and inner bark or between the inner bark and cambium. In logs that were cut more than 4 months prior to inoculation, larvae were unable to complete development. In logs cut 2 weeks prior to inoculation, almost all larvae were able to reach the adult stage but they were smaller in size than adults from living trees damaged by this borer. These results suggest that poor nutrient conditions in the inner bark of logs affected development and survival of the borer. Because of its nutritional advantage, living cedars provide a better environment for the sugi bark borer. However, all larvae are killed by resin flow, suggesting that this insect is “in between” being primary and secondary with respect to living trees, or a “weak” primary insect. The sugi bark borer seems to develop early in the season so that early instar larvae encounter reduced amounts of resin flow and so that late-instar larvae feed mostly in summer when nutrient levels in the inner bark are at their highest.