Analysis of chemical structure of wood charcoal by X-ray photoelectron spectroscopy

Wood charcoal carbonized at various temperatures was analyzed by X-ray photoelectron spectroscopy (XPS), Fourier-transform infrared spectroscopy (FTIR), and X-ray diffractometry to investigate the changes of chemical structures during the carbonization process. From the infrared spectra, the carbon double bonds and aromatic rings were seen to form at a carbonization temperature of about 600°C. From the XPS spectra, the ratio of aromatic carbons increased in the temperature range 800–1000°C and over 1800°C. The condensation of aromatic rings proceeded as carbonization progressed. The drastic reduction of electrical resistivity of charcoals was observed in almost the same temperature range. It was found that the condensation of aromatic rings had some relation to the decline in electrical resistivity. Wood charcoal carbonized at 1800°C was partly graphitized, a finding supported by the results of X-ray diffraction and XPS. The functional groups containing oxygen diminished with the increase in carbonization temperature.This paper was presented at the 45th Annual Meeting of the Japan Wood Research Society in Tokyo, April 1995 and at the 47th Annual Meeting of the Japan Wood Research Society in Kochi, April 1997     

Reactivity of wood charcoal with ozone

We investigated the resistance of wood charcoal against ozone and estimated the half-life of the charcoal in air. The weight of wood charcoal prepared by the carbonization of Fagus crenata sawdust at 400°C (C-400) was not affected with up to 8.5% ozone while the charcoal prepared at 1000°C (C-1000) burned with 4.9% ozone. Pores with a diameter of approximately 100–200nm were observed on the surface of ozone-treated C-1000 by scanning electron microscopy, although no pores were found in ozone-treated C-400. The peak positions of the C1s spectra and the full width at half maximum of X-ray photoelectron spectrum peaks suggest that C-400 has an amorphous structure composed of aliphatic carbons and small aromatic molecules while C-1000 and activated charcoal (AC) are polyaromatic. It is likely that the aromatic layers of C-1000 and AC were destroyed and the edge carbon atoms were removed as CO or CO₂ by ozone oxidation. We estimated the half-life of C-1000 with ozone in air to be about 50000 years by assuming that the weight of C-1000 decayed exponentially. Thus, it is suggested that wood charcoal is stable on a geological time scale.     

Intercalation of wood charcoal with sulfuric acid

Intercalation of wood charcoal with sulfuric acid (H₂SO₄) was investigated. Carbonized sugi (Japanese cedar) samples were prepared by heating at various temperatures in the range 1700°–2700°C. Electrochemical oxidization was carried out in H₂SO₄ and the feasibility of intercalation was determined. In potentiometric analysis, plateaus appeared for samples carbonized at temperatures above 2300°C. In their X-ray diffraction profiles, the peak at around 26° was shifted to a smaller angle of about 22.4°. These results can be considered as signs of intercalation with acid molecules. Fourier transform infrared analysis of charcoal heated at 2700°C, following washing with water and drying of the sample, showed a band at 1220 cm⁻¹ that was assigned to a sulfonate group. This band was not observed for samples heated at 1900°C. These observations suggest the occurrence of intercalation in the former charcoal, but not in the latter. It is concluded that wood charcoal can undergo intercalation when it has ordered stacking of hexagonal carbon layers. Part of this article was presented at the 55th, 56th, and 57th Annual Meetings of the Japan Wood Research Society, Akita, Hiroshima, and Tsukuba, August 2006, August 2007, and March 2008, respectively, and at the International Conference on Carbon “CARBON 2008,” Nagano, July 2008     

Cone structure of hexagonal carbon sheets stacked in wood cell lumen

Cone-shaped carbon particles were produced inside the cell lumen of sugi (Japanese cedar) charcoal treated at 2500°C. We succeeded in clarifying the structural and morphological features by separating the cone-shaped carbon from the carbonized cell wall by heating to 800°C in air. Cone-shaped carbon is less susceptible to oxidation than the carbonized cell wall. The isolated cone-shaped carbon and carbonized cell wall fracture were observed separately by transmission electron microscopy and selected area electron diffraction. Results revealed that the cone-shaped carbon has a very highly ordered cone structure with regularly stacked hexagonal carbon sheets, whereas the carbonized cell wall has a disordered structure of mosaic-like turbostratic carbon.Part of this work was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002     

Growth of cone-shaped carbon material inside the cell lumen by heat treatment of wood charcoal

Conclusions With treatment at 2500°C, wood cell walls partially transform into a turbostratic carbon structure, which has an X-ray diffraction peak corresponding to a layer plane spacing of 0.343 nm. Despite this change, there was no apparent change within the cell wall seen by SEM.Cone-shaped carbon material was formed inside the cell lumen after treatment at 2500°C. This is not a feature originating from any wood cell organism and seems to result from vaporized carbon or pyrolysis gases that originate within the cell wall.Part of this work was presented at the 52nd Annual Meeting of the Japan Wood Research Society, Gifu, April 2002     

Sorption properties of torrefied wood and charcoal

Abstract

Pre-treating biomass by torrefaction is assumed to improve the material's storage properties because of reducing hydrophilicity. In order to assess the effect of sorption on storage properties, the adsorption of water vapour and capillary absorption of liquid water in torrefied and charred spruce and birch were studied. In addition, the chemical changes were evaluated through Fourier Transform Infrared (FT-IR) spectroscopy. Adsorption decreased notably as severity of treatment increased, as was expected due to degradation of the wood constituents, namely hemicelluloses and amorphous cellulose. Capillary absorption increased with increasing severity in spruce samples while birch showed less change, but the maximum volume for absorption increased with both species. FT-IR results showed an increase in aromatic structures that have a role in forming crystalline structures, possibly leading to increased porosity. Torrefied and charred material should not be stored outside, as liquid water absorbs readily into the material, turning it into a suitable substrate for fungi.     

Three-dimensional visualization of soil pore structure using computed tomography

The geometric and spatial characteristics of pore structures determine the permeability and water retention of soils, which have important effects on soil functional diversity and ecological restoration. Until recently, there have not been tools and methods to visually and quantitatively describe the characteristics of soil pores. To solve this problem, this research reconstructs the geometry and spatial distribution of soil pores by the marching cubes method, texture mapping method and the ray casting method widely used in literature. The objectives were to explore an optimal method for three-dimensional visualization of soil pore structure by comparing the robustness of the three methods on soil CT images with single pore structure and porosity ranging from low (2–5%) to high (12–18%), and to evaluate the reconstruction performance of the three methods with different geometric features. The results demonstrate that there are aliases (jagged edges) and deficiency at the boundaries of the model reconstructed by the marching cubes method and pore volumes are smaller than the ground truth, whereas the results of the texture mapping method lack the details of pore structures. For all the soil images, the ray casting method is preferable since it better preserves the pore characteristics of the ground truth. Furthermore, the ray casting method produced the best soil pore model with higher rendering speed and lower memory consumption. Therefore, the ray casting method provides a more advanced method for visualization of pore structures and provides an optional technique for the study of the transport of moisture and the exchange of air in soil.     

竹炭利用综合评述

根据目前国内外竹炭产业发展的状况,综述了竹炭应用现状。主要包括竹炭在农林畜牧业、医疗保健、环境保护等不同方面的应用,同时对竹炭的进一步研究和应用提出些建议和展望。     

THE DETECTION OF THE BOUNDARY OF IMAGE OF WOODANATOMICAL STRUCTURE MOLECULAR

INTRODUCTIONWiththedevelopmentofcomputerandseniorthehnology,imagcprocessingtechnol-ogr-hasmadeagreetprogrssandbeenap-pliedtomedicalscience.mechanicalflawde-tection,industrialcontrol,geologicalprosPeCt-ing.archaeology,astronomy'chemisty.'Phys-icsctc.Eventhoughithasjustbeenappliedinwoodscicnceforashorttime'imopprocess-ingtechnologyshowabroadprosPeCts.Thesegmentationofimagepsdthecollcc-tionofimageboundaryisoncofthemostclas-sictasksforstUdyinimageproc6ksing,imagcanal}'sisandcomputcr\,ision.…     

竹炭的种类和用途

主要介绍竹炭的种类和它的主要用途,包括作燃料、空气净化与湿度调节、净化水、土壤改良、保鲜、卫生保健、屏蔽电磁波、工艺品制作等。     

加工活性炭处理松材线虫病死木技术的研究

经３ａ的试验和实践结果表明，加工活性炭处理松材线虫病死木中松褐天牛成、幼虫等媒介昆虫是一项简单易行、灭害彻底、效益较高的处理松材线虫病死木的新技术，值得在疫区推广应用。     

Dielectric relaxation due to the heterogeneous structure of wood charcoal

Delignified hinoki wood and cellulose as well as hinoki and lauan woods were carbonized at 590°C for 1 h. The dielectric properties of these specimens were measured at 20°C in a frequency range of 20 Hz to 1 MHz. Inflection points in the dielectric constant (ε′) versus the logarithm of frequency (log f) curves as well as in the logarithm of the electric conductivity (log σ) versus log f curves for all specimens prepared were recognized. Peaks in the dielectric loss and the imaginary part of the complex conductivity versus the log f curves were detected in the frequency location corresponding to the inflection point in the ε′ and log σ versus log f curves. It was considered that this relaxation was responsible for the interfacial polarization observed in heterogeneous materials because no permanent dipoles existed in the specimens carbonized above 500°C. The Cole–Cole circular arc law was applied to account for this relaxation. Similar average relaxation times were obtained for all specimens. These results suggested that the observed relaxation was ascribed to interfacial polarization at microscopic levels in the cell walls.     

传统木材生产与效益木材生产

本探讨了传统木材生产和效益木材生产的区别，并从生产方式和经营模式上具体论述了传统木材生产和效益木材生产。     

木材干燥产生缺陷的预防措施及补救方法

缺陷对木材的加工及使用影响很大 ,本文对木材干燥产生的缺陷及产生的原因进行了探讨 ,提出干燥引起缺陷的预防措施。     

WOODPRO木材解剖特征图象处理系统的开发

本文简要地介绍了WOODPRO木材解剖特征图象处理系统；并结合木材细胞图象特点，描述了计算机图象处理技术在FFT图谱构建、木材细胞几何参数测量等方面的应用。     

机制空心炭市场预测及发展趋势

本文较为详细地论述了国内外机制空心炭市场发展方向,为机制空心炭生产的可行性研究提供了市场预测的依据。     

Production and spatial price differences for charcoal in Uganda

Charcoal production activity assumes importance not only for generating large employment and income and supplying major fuel requirements in Uganda but also for triggering environmental degradation. Based on production and marketing data collected from one of the important charcoal producing districts, namely, Nakasongola, this study found that charcoal production being less capital intensive and risk free, is mainly carried out by numerous small, economically weak and unorganised individual producers. The price-distance relationship was analysed for the average prices of a bag of charcoal prevalent in each town over a stretch of 140 km between Kampala, the capital and main consuming center for charcoal in Uganda, and Kafu Bridge during the years 1995 and 1999. A movement of 1 km from Kampala resulted in a price decline of about 28 UShs in 1995 and 33 UShs in 1999 (prices held constant at 1995 level). The price-distance relationship and responsiveness of charcoal prices to distance from Kampala, as measured through distance elasticity of price, remained unchanged over the period 1995 to 1999. There is no statistical evidence to prove that the charcoal producers were better paid in 1999 than in 1995. It appears unlikely to halt the harmful environmental degradation effects of charcoal making activity without generating adequate alternate employment opportunities in rural areas and internalizing the full environmental costs of forest degradation in the consumer price of charcoal.     

Water sorption,surface structure and surface energy characteristics of wood composite fibres refined at different pressures

During fibre processing, wood fibres are subjected to a range of physical and chemical conditions sufficient to slightly alter their chemical composition and hence their ultimate performance when used in the manufacture of wood fibre-based composites. In order to better understand the effects of refiner conditions on material performance, wood fibres were subjected to processing at different refiner pressures (4, 6, 8 and 10 bar) and subsequently dried in a flash drier. The fibres were analysed for changes in surface area, surface energy, surface structure and water vapour sorption characteristics. The methods applied were nitrogen adsorption utilising the Brunauer–Emmett–Teller theory, inverse gas chromatography, scanning electron microscopy and dynamic vapour sorption. It was found that increasing refiner pressure resulted in fibres of lower surface area, accompanied by increasing dispersive surface energies up to operating refiner pressures of 8 bar. It was found with fibres refined at different pressures that as the refiner pressure increased the equilibrium moisture content of the fibre decreased at the set relative humidities. However, it was also noted that the hysteresis was not significantly different between each of the refiner pressures. The results suggest that different refiner pressures can be used to tune the surface characteristics which may be beneficial to product development and the improvement of the environmental profile of the wood fibre composites.