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1.
Kengo Ishimaru Tomas Vystavel Paul Bronsveld Toshimitsu Hata Yuji Imamura Jeff De Hosson 《Journal of Wood Science》2001,47(5):414-416
Conclusions Various carbon structures were observed in the wood charcoal sample: the well known pyrolytic graphite layers, onion-like particles, and diamond structure. It is suggested that wood charcoal carbonized at 700°C is a complex of various carbon structures. The pore structure was observed by electron microscopy, and it is supposed that the microstructure and pores are closely related. Further study of the microstructure during the carbonization process of charcoal is necessary to better understand the characteristic functions of wood charcoal for utilizing it as a source of carbon material.A summary of this study was presented at the 51st annual meeting of the Japan Wood Research Society, Tokyo, April 2001, and the 50th annual meeting of the Society of Materials Science, Osaka, May 2001 相似文献
2.
Reactivity of wood charcoal with ozone 总被引:8,自引:0,他引:8
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. 相似文献
3.
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 相似文献
4.
Koei Nishimiya Toshimitsu Hata Yuji Imamura Shigehisa Ishihara 《Journal of Wood Science》1998,44(1):56-61
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 相似文献
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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 相似文献
7.
Maija Kymäläinen Mikko Havimo Jarmo Louhelainen 《Wood material science & engineering》2014,9(3):170-178
AbstractPre-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. 相似文献
8.
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 相似文献
9.
The influence of inorganic matter on the pyrolysis of Japanese cedar (Cryptomeria japonica) wood was studied at a gasification temperature of 800°C with demineralization through acid washing. Some influences on the
formation of char, tar, and low molecular weight products coincided with results reported at temperatures lower than the gasification
temperature. However, the carbonization behavior of the volatile products and the yield of polysaccharide fraction were not
able to be explained as a sum of the pyrolysis of cellulose, hemicellulose, and lignin even after demineralization. These
results suggest some interactions between wood constituent polymers other than the influence of inorganic matter. 相似文献
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11.
Sakae Horisawa Yutaka Tamai Yoh Sakuma Shuichi Doi Minoru Terazawa 《Journal of Wood Science》2000,46(4):317-321
The optimum working moisture content of a wood matrix for the garbage automatic decomposer-extinguisher (GADE) machine was investigated using a small-scale degradation reactor. A formula feed for rabbits was used as the model waste. The degradation experiment was conducted under controlled conditions such as moisture content, environmental temperature, and airflow rate. The degradation rate was estimated precisely from weight loss and the CO2 evolution rate. The degradation rate were nearly constant at a moisture content of 30%–80% on a-wet-weight basis. Microorganisms from the environment propagated in the reactor with no inoculums added. The number of microorganisms showed a trend similar to that of the degradation rate. The microorganism community changed according to the moisture content of the matrix and were considered to attain a constant degradation rate at a wide range of moisture content of a matrix.Part of this report was presented at the 49th annual meeting of the Japan Wood Research Society, Tokyo, April 1999 相似文献
12.
农用货车在木材生产中应用的评价 总被引:1,自引:1,他引:1
从经济改革,南方林区道路状况,结合农用货车性能特点。通过与EQ1090、CA1090等车型各方面比较,对农用货车在木材生产中应用作出了评价。 相似文献
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14.
Woodsurfaceroughnessisthemicrogeometrypropertycomposedbyalittlespacingandpeak-tovalley.Generallythesurfaceroughnesswascomposedbytheworkingmethodandotherfactorst123.Woodsurfaceroughnesswasnotonlyanimportantindexwhichmeasuredthesur-facesmoothextentofwoodproductandtheworkingqualitybutalsothewoodsur-fitceroughnessaffectedwoodsurfacefeel--lngandpsychologicalfeeling[3'4,lo,ll:.Th,'quantitativesurftlceproPertyparametersweretheimportantpartwhichmarkedthewoodsurfacevisualpsycho1ogicalmagni-tude,whichha… 相似文献
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Charalampos Lykidis Ioannis Barboutis Athanasios Grigoriou 《Wood material science & engineering》2016,11(5):254-260
This paper investigates the basic hygroscopic properties and formaldehyde content (FC) of particleboards produced with wood biomass from fruit tree branches and evergreen hardwood shrubs as substitute raw materials for fir particles. One-layer laboratory particleboards with two distinct target densities (0.63 g/cm3 and 0.69 g/cm3) were produced using various mixtures of the above materials. Industrially produced wood particles were also used for comparison purposes. The results showed that the replacement of fir wood (FW) by evergreen hardwood material significantly upgraded board's quality in terms of thickness swelling (TS) and water absorption (WA) (except boards with density of 0.63 g/cm3) after immersion in water for 24 h and residual swelling (RS) after reconditioning. The contribution of branch-wood (BW) particles in the production of FW boards with density of 0.63 g/cm3 induced increase of TS, WA, and RS while for boards with density of 0.69 g/cm3 did not result to significant changes except for RS. In terms of FC, boards made of BW and evergreen hardwood showed significantly lower FC compared to those produced by FW and industrial particles. 相似文献
17.
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. 相似文献
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Inthe21stcentury,thewoodsupplyinChinawillcontinLJetobelessthanthedemand,soChinawillneedtousewoodasetfectivelyasPossible.Theuseotwoodcompositesisaveryefficientwaytosavewood.ChinalackssLJfficientforeststomeetitsdemandforwood,especiallyinfinequalitywoods.BecauseofChina'spopulationandfiberdemand,efficientuseofwoocJismoreimportanttoChinathanthattosomeothercoLJntries.However,Chinawasneitherconvincedofthisandnordiditpayattentiontothestudyofwoodcompositesbeforethe1970's.FacingthewoodcrisisChinaf… 相似文献
20.
Dynamics of large wood in an eastern U.S. mountain stream 总被引:1,自引:0,他引:1
Large wood (LW) is an important feature in many streams in northeastern North America, yet the dynamics (recruitment, movement, and export) of large wood remain largely undocumented for streams in this region. In this study we quantify the dynamics of LW in 400 m of a second-order, high gradient, boulder-dominated stream in the eastern Adirondack Mountains, NY. Characteristics and location of all LW (>1-m length, >10-cm diameter) in the 400-m study reach were initially recorded and pieces were individually tagged in November 2000. Subsequent surveys were conducted in late summer/fall of 2001, 2003, and 2004. Twenty-six% of the 112 pieces of LW initially tagged moved 5.0 m or more during the 4 years of this study. Mobile wood was, on average, shorter than non-mobile wood. Nearly all mobile wood was shorter than the 8.0-m bankfull width of the stream. From 2000 to 2004, 2.16 m3 (0.54 m3 100 m−1; 43 pieces) of LW entered the study reach and 0.7 m3 (0.18 m3 100 m−1; 13 pieces) left the stream. Retention of wood in debris dams was key to reducing potential export. For this stream, located within a second-growth mixed northern hardwood riparian forest that is approaching maturity, the net wood accumulation rate was estimated as ranging from 0.09 to 0.15 m3 100 m−1 year−1. Our data support previous observations that LW length strongly influences its potential to move in high gradient streams, though debris dams can reduce LW movement rates and movement distances for wood of all sizes. 相似文献