• Carbon letters
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• v.14 no.2
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• pp.94-98
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• 2013

Isotropic pitch fibers were stabilized and carbonized for preparing carbon fibers. To optimize the duration and temperature during the stabilization process, a thermogravimetric analysis was conducted. Stabilized fibers were carbonized at 1000, 1500, and $2000^{\circ}C$ in a furnace under a nitrogen atmosphere. An elemental analysis confirmed that the carbon content increased with an increase in the carbonization temperature. Although short graphitic-like layers were observed with carbon fibers heat-treated at 1500 and $2000^{\circ}C$, Raman spectroscopy and X-ray diffraction revealed no significant effect of the carbonization temperature on the crystalline structure of the carbon fibers, indicating the limit of developing an ordered structure of isotropic pitch-based carbon fibers. The electrical conductivity of the carbonized fiber reached $3.9{\times}10^4$ S/m with the carbonization temperature increasing to $2000^{\circ}C$ using a four-point method.

• Proceedings of the Korean Society For Composite Materials Conference
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• 2001.10a
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• pp.133-136
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• 2001

The effect of pre-carbonization condition on the mechanical properties of nonwoven needle-punched carbon/phenolic composite was studied. The nonwoven Oxi-PAN felt was pre-carbonized at different temperature. The pre-carbonized Oxi-PAN felt was needle-punched and then carbonized. Needle-punched nonwoven carbon preforms were formed into composites with phenol resin. The tensile and flexural strengths showed maximum value with pre-carbonization temperature of $500^{\circ}C$. Compared with the non-pre-carbonized composite, the mechanical properties were slightly improved.

• Journal of Forest and Environmental Science
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• v.22 no.1
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• pp.32-40
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• 2006

Structure change of Quercus variabilis charcoal during the carbonization temperature was investigated by scanning electron microscopy. Volume of wood sample decreased with increasing the carbonization temperature, and checks were occurred along with radial direction. SEM observation indicated that the all wood cells presented the layering structure at $250^{\circ}C$ and $300^{\circ}C$. However, the cross section of cell walls at $340^{\circ}C$ and over showed an amorphous-like structure without cell wall layering.

• Carbon letters
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• v.8 no.1
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• pp.43-48
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• 2007

The influences of various carbonization temperatures on electrical resistivity and morphologies of polyacrylonitrile (PAN)-based nanofiber webs were studied. The diameter size distribution and morphologies of the nanofiber webs were observed by a scanning electron microscope. The electrical resistivity behaviors of the webs were evaluated by a volume resistivity tester. From the results, the volume resistivity of the carbon webs was ranged from $5.1{\times}10^{-1}\;{\Omega}{\cdot}cm$ to $3.0{\times}10^{-2}\;{\Omega}{\cdot}cm$, and the average diameter of the fiber webs was varied in the range of 310 to 160 nm with increasing the carbonization temperature. These results could be explained that the graphitic region of carbon webs was formed after carbonization at high temperatures. And the amorphous structure of polymeric fiber webs was significantly changed to the graphitic crystalline, resulting in shrinking the size of fiber diameters.

• Macromolecular Research
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• v.10 no.6
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• pp.318-324
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• 2002

In this paper we have extensively studied what and how processing parameters for quasi-carbonization influence the breaking strength and modulus of resulting quasi-carbon fabrics that are prepared from stabilized PAN fabrics with a spun yarn texture. Seven processing parameters have been considered as follows: applied tension, final heat-treatment temperature, heating rate, heating step, holding time, cooling rate, and purging gas purity. The results indicate that optimal uses of applied tension, final heat-treatment temperature, heating rate, and heating step during quasi-carbonization process are primarily important to increase the tensile properties of quasi-carbon fabrics and holding time, cooling rate, and purging gas purity are less importantly contributed.

• Journal of Korea Foresty Energy
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• v.25 no.1
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• pp.9-17
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• 2006

Properties of wood charcoal made from the domestic wood species at $300-900^{\circ}C$ have investigated to understand the correlation between carbonization temperature and chemical and physical characteristics of wood charcoal. In terms of charcoal yield at particular carbonization temperatures, it was drastically decreased until the temperature reaches up to $600^{\circ}C$ and the decrease ratio of yield was reduced at higher temperatures. As the carbonization temperature increased, pH of the wood charcoal increased so that it became basic at last. The wood charcoal prepared at $600{\sim}700^{\circ}C$ showed the highest caloric value and those of wood charcoals made at higher temperature became plateau at a little lower level than the peak. The caloric value of Japanese larch charcoal was a bit higher than that of Red oak charcoal. The carbon content in the wood charcoal was increased as the carbonization temperature increased, whereas the hydrogen content was decreased. Specific surface area of the wood charcoal became larger with increase in temperature up to $600^{\circ}C$ but it was decreased or reduced in the increasing ratio after, and then it rose again at higher temperature than $800^{\circ}C$. Absorption capacity of the wood charcoal against iodine and gaseous acetic acid became greater as the carbonization temperature increased. Japanese larch charcoal presented higher absorption capacity than Red oak charcoal. As the above results, it is revealed that carbonization temperature affects the chemical and physical properties of wood charcoal. Therefore, to use wood charcoal with maximum effect it should be prepared at optimum temperature for proper use.

• Journal of the Korean Wood Science and Technology
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• v.39 no.3
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• pp.230-237
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• 2011

The study was performed to investigate the characteristics of charcoal and temperature change of a kiln's inner and outer walls in carbonization process using improved kiln. In this kiln system, carbonization process was completed in eight days. In the kiln, the ignition temperature was kept about $720^{\circ}C$. And then the temperature were increased gradually prior to be refined. Finally, the temperature in refining process was reached to maximum point, $1,000^{\circ}C$. In the chimney, the temperature was increased gradually from $90^{\circ}C$ at ignition to $750^{\circ}C$ at refining. The temperature change of the kiln wall resembles a temperature change progress curve during a carbonization process. The highest temperature of the kiln wall that appeared by a carbonization process was around $500^{\circ}C$. As a result of having measured an inner wall and the outer wall of the kiln using an infrared thermography camera, it was judged with there being considerable latent heat on kiln wall and ceiling. Fixed carbon contented of charcoal was 85.9~89.9%. Refining degree of charcoal, hardness, calorific value and pH were l, 12, 7,047~7,456 kcal/kg, 9.0~9.9, respectively. The yield of wood charcoal was 13.8%, and compared to conventional kiln's yield increased 1.5%.

• Journal of the Korean Wood Science and Technology
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• v.38 no.1
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• pp.43-48
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• 2010

This study was aimed at offering basic data to develop a new use of sawdust and rice husk. The results of this study were as follows: In surface temperature of ceramics by resin impregnation rate, the velocity was great in the early time of heat transfer because the temperature precipitously increased to 10 minutes elapsed. Also, the surface temperature of ceramics manufactured in resin impregnation rate of 60~70% indicated the highest. Heat transfer was fast in terms of the changes in surface temperature of ceramics according to the carbonization temperature, as because the density of ceramics made on condition of the carbonization temperature of $1000^{\circ}C$and $1200^{\circ}C$ was high. Moreover, ceramics maintained heat for a long time because the descent velocity of surface temperature of ceramics was slower than that of heater.

• Journal of the Korean Wood Science and Technology
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• v.42 no.5
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• pp.615-623
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• 2014

Increases of public attention on healthy environment lead to the regulation of indoor air quality such as Clean Healthy House Construction Standard. This standard covers emission of total volatile organic compounds (TVOCs) (e.g., formaldehyde, benzene, and toluene), ventilation, and use of environmentally-friendly products or functional products. Moisture absorption and desorption abilities are a recommended functionality for improving indoor air quality. In this study, moisture absorption and desorption capacities of carbonized board from wood-based panels and other materials were determined by using UNT-HEAT-01 according to ISO 24358:2008. Pine had higher moisture absorption and desorption capacities ($49.0g/m^2$ and $35.3g/m^2$, respectively) than hinoki cypress, cement board, gypsum board, oriented strand board, and medium density fiberboard (MDF). The moisture absorption and desorption capacities differed considerably according to the wood species. After carbonization process at $400^{\circ}C$, the absorption and desorption ability of MDF increased to 38% and 60%, respectively. However, moisture absorption and desorption capacities decreased with increasing carbonization temperature, but they were still higher than original MDF. Therefore, it is suggested that carbonization below $600^{\circ}C$ can improve moisture absorption/desorption capacities.

• Transactions of the Korean hydrogen and new energy society
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• v.28 no.4
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• pp.426-432
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• 2017

Hydrothermal carbonization (HTC) is an effective and environment friendly technique; it possesses extensive potential towards producing high-energy density solid fuels. it is a carbonization method of thermochemical process at a relatively low temperature ($180-250^{\circ}C$). It is reacted by water containing raw material. However, the production and quality of solid fuels from HTC depends upon several parameters; temperature, residence time, and pressure. This study investigates the influence of operating parameters on solid fuel production during HTC. Especially, when food waste was reacted for 2 hours, 4 hours, and 8 hours at $200^{\circ}C$ and 2.0-2.5 MPa, Data including heating value, proximate analysis and water content was consequently collected and analyzed. It was found that reaction temperature, residence time are the primary factors that influence the HTC process.