• Carbon letters
• /
• v.28
• /
• pp.24-30
• /
• 2018

Coke aggregates and carbon artifacts were produced to investigate the interactions of coke and pitch during the kneading process. In addition, the kneading ratio of the coke and binder pitch for the coke aggregates was controlled to identify the formation of voids and pores during carbonization at $900^{\circ}C$. Experiments and thermogravimetric analysis revealed that carbon yields were improved over the theoretical yield calculated by the weight loss of the coke and binder pitch; the improvement was due to the binding interactions between the coke particles and binder pitch by the kneading process. The true, apparent, and bulk densities fluctuated according to the kneading ratio. This study confirmed that an excessive or insufficient kneading ratio decreases the density with degradation of the packing characteristics. The porosity analysis indicated that formation of voids and pores by the binder pitch increased the porosity after carbonization. Image analysis confirmed that the kneading ratio affected the formation of the coke domains and the voids and pores, which revealed the relations among the carbon yields, density, and porosity.

• Applied Chemistry for Engineering
• /
• v.34 no.2
• /
• pp.153-160
• /
• 2023

In this study, biochar was produced from biomass waste, and its methylene blue adsorption capacity was evaluated. The major components of the biomass were cellulose, hemicellulose, and lignin. Ash content was high in waste wood. Carbonization yield decreased as carbonization temperature increased, as did hydrogen and oxygen content, but carbon content increased. Increased carbonization temperature also increased the specific surface area and micropores of biochar. At 600 ℃, biochar had the highest specific surface area (216.15~301.80 m² /g). As a result of methylene blue adsorption on biochar carbonized at 600 ℃, oak, waste wood, and pruned apple tree branches fit the Freundlich model, while pruned peach tree branches fit the Langmuir model. In the adsorption kinetics of methylene blue on biochar, oak and pruned peach tree branches fit a pseudo-first-order model, while waste wood and pruned apple tree branches fit a pseudo-second-order model.

• Journal of Environmental Science International
• /
• v.13 no.2
• /
• pp.161-165
• /
• 2004

This study has been conducted to develop a new recycling technology of sewage sludge using a carbonization process. The carbonizing yield, the calorific value and EC(electric conductivity) of carbonized sewage sludge had a tendency to be decreased with increase of the carbonizing temperature and time, but pH and the C/N were increased with increase the carbonizing temperature and time. The whole pore volume of carbonized sludge processed in the carbonizing furnace was /g, which was smaller than that in the electric furnace. But, the rates of mesopore and macropore were found to account for 100% therein. Rate of color and organic materials removal for dyeing wastewater were determined 70~97%, 78~83% on cotton yarn, 88~96%, 69~80% on wool wastewater and 77~89%, 77~87% on towel compared with powder activated carbon. Effect of carbonized sludge on chrysanthemum growth was investigated. Plant height and number of leaves was better mixture of carbonized sludge than comparison.

• Composites Research
• /
• v.29 no.4
• /
• pp.132-137
• /
• 2016

Based on mussel-inspired polydopamine (PDA), a novel technique to fabricate carbon nanowire (CNW) arrays is presented for a possible use of porous carbon electrode in electrochemical energy storage applications. PDA can give more porosity and nitrogen-doping effect to carbon electrodes, since it has high graphitic carbon yield characteristic and rich amine functionalities. Using such outstanding properties, the applicability of PDA for electrochemical energy storage devices was investigated. To achieve this, the decoration of the CNW arrays on carbon fiber surface was performed to increase the surface area for storage of electrical charge and the chemical active sites. Here, zinc oxide (ZnO) nanowire (NW) arrays were hydrothermally grown on the carbon fiber surface and then, PDA was coated on ZnO NWs. Finally, high temperature annealing was performed to carbonize PDA coating layers. For higher energy density, manganese oxide ($MnO_x$) nanoparticles (NPs), were deposited on the carbonized PDA NW arrays. The enlarged surface area induced by carbon nanowire arrays led to a 4.7-fold enhancement in areal capacitance compared to that of bare carbon fibers. The capacitance of nanowire-decorated electrodes reached up to $105.7mF/cm^2$, which is 59 times higher than that of pristine carbon fibers.

• Journal of the Korean Wood Science and Technology
• /
• v.26 no.2
• /
• pp.6-15
• /
• 1998

A total of forty five-ply, 30- by 30-cm lauan and larch plywood sheets were manufactured in the laboratory using commercial urea and phenol resin adhesives; half of these sheets were treated with fresh concrete. Each sheet was carbonized for 2, 4, and 6hours at $400^{\circ}C$, $600^{\circ}C$, and $750^{\circ}C$, respectively, and their physical properties were measured. The yie1d of charcoal decreased as carbonization temperature and time increased. Charcoal yield was greater in plywood than in veneer, and slightly greater in plywood treated with concrete compared to untreated plywood. Plywood manufactured with phenol resin adhesive had higher pH, higher equilibrium moisture content (EMC), and greater adsorption of methylene-blue dye compared to plywood manufactured with urea resin. For concrete-treated plywood, pH was greater than 10 even when the sheets were carbonized for 2hours at $400^{\circ}C$. Although the EMC of the phenol resin plywood was higher than that of the urea resin plywood, EMC of the phenol resin was lower than that of the urea resin. The larch phenol resin plywood that was carbonized for 6 hours at $750^{\circ}C$ adsorbed more methylene-blue than did the commercia1 wood-based activated charcoal as a result of total pore volume and surface area.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.25 no.4
• /
• pp.36-42
• /
• 2021

In this study, the impregnation of Lyocell fabrics was performed using phosphoric acid, ammonium phosphate, diammonium hydrogen, triammonium phosphate as phosphorus flame retardant, to fabricate continuous graphite fabrics using lyocell fiber. The physical and chemical structure changes were investigated by thermogravimetric, Fourier-transform infrared spectroscopy, C-nuclear magnetic resonance, X-ray diffraction, and weight analyses, By analyzing the thermal behavior of phosphorus flame retardant, conditions for the temperature, gas, and residual time of the pyrolysis process were set. Graphite fabrics with a tensile strength of 1,007.19±11.47 N/5 cm and yield of 25.3% were fabricated using continuous pyrolysis, carbonization and graphitization process.

• Journal of Korea Foresty Energy
• /
• v.22 no.3
• /
• pp.49-56
• /
• 2003

As a part of agricultural utilization of charcoal and pyroligneous acid, the effect of wood carbonization products on the growth of red pepper and soil microorganisms was investigated. The treatment of charcoal and pyroligneous acid provided good growth conditions to microorganisms through neutralizing soil acidity and improving the physicochemical properties of soil. Therefore the density of useful microorganism in the soil has been increased. In the growth of red pepper, the length, diameter, and the fruit numbers of red pepper have been increased by treating with wood carbonization products. It was especially shown that yield has increased about 50% in the fruit number, by treating charcoal 1kg, 1000 time-diluted solution of pyroligneous acid and bacteria, compared with the control. It was estimated that increasing the length of seedling and the diameter of red pepper stem contributed to the resistance against the prerequisites of various environmental changes in open field. Therefore, the final yield would be increased. In the antagonism experiment of red pepper mold (Colletotrichum gloeosporioides), the mold became extinct in the 2- and 10-time diluted solution of pyroligneous acid, compared with the control. On the other hand, their growth speed was delayed in the 100- and 1000 time-diluted solution.

• Korean Journal of Materials Research
• /
• v.8 no.4
• /
• pp.299-303
• /
• 1998

We examined, using thermoanalytical methods, the effects of $2000^{\circ}C$ heat-treated graphite powders and heating rate of cure after impregnation on the thermal stability and carbon yield of furfuryl alcohol, which is frequently used not only as an impregnant but also as a matrix precursor for carbon fiber-reinforced carbon composites. It was founded that the addition of 30wt% graphite powders to furfuryl alcohol and the heating rate of $35^{\circ}C$/min showed the highest thermal stability of furfuryl alcohol/graphite powder mixture. The carbon yield above $1000^{\circ}C$ was enhanced more than 10% in comparison with the absence of graphite powders. It would be expected that this result can contribute to some extent to reduce the repeating number of processing cycle (carbonization-impregnation-cure-re-carbonization) required to densify a carbonaceous composite.

• Journal of the Korean Wood Science and Technology
• /
• v.28 no.2
• /
• pp.57-65
• /
• 2000

Objective of research is obtain fundamental data of carbonized wood wastes for soil condition, de-ordorization, absorption of water, carrier for microbial activity, and purifying agent for water quality of river. The carbonization technique and the properties of carbonized wood wastes(wood-based materials) were analyzed. Proximate analysis showed the wood-based materials contains 0.37~2.27% ash, 70~74% volatile matter, and 17~20% fixed carbon. As carbonization temperature was increased, the charcoal yield was decreased. However, no difference in charcoal yield was found due to time increase. The specific gravity after the carbonization decreased about 30~40% comparing to green wood. The charcoal had 1.08~4.18% ash, 5.88~13.79% volatile matter, and 80.15~90.94% fixed carbon. The pH of plywood and particleboard(pH 9 at $400^{\circ}C$, pH 10 at $600^{\circ}C$ and $800^{\circ}C$) made charcoals was higher than that of fiberboard. The water-retention capacity was not affected by the carbonization temperature and time. The water-retention capacity within 24h was about 2~2.5 times of sample weight, and the Equilibrium moisture content(EMC) became 2~10% after 24h. EMC of charcoal from the thinned trees were 9.40~11.82%($20^{\circ}C$, RH 90%), 6.87~7.61%($20^{\circ}C$, RH 65%), and 1.69~2.81%($20^{\circ}C$, RH 25%). EMC of charcoal from the wood-based materials under $20^{\circ}C$, relative humidity(RH) 90% was similar to EMC of charcoal from the thinned trees(9~11 %). However, under $20^{\circ}C$, RH 25.65%, EMC of charcoal from the wood-based materials were higher(2~3%) than EMC of charcoal from the thinned trees. Every charcoal from the wood-based materials fulfilled the criteria in JWWA K 113-1947.

• Carbon letters
• /
• v.16 no.1
• /
• pp.62-66
• /
• 2015

In this study, carbonized fibers were prepared by using acidically cross-linked LDPE fibers. The surface morphologies of the carbonized fibers were observed by SEM. The effects of cross-linking process temperatures were studied using thermal analyses such as DSC and TGA. The melting and heating enthalpy of the fibers decreased as the cross-linking temperature increased. The cross-linked fibers had a carbonization yield of over 50%. From SEM results the highest yield of carbonized LDPE-based fibers was obtained by cross-linking at a sulfate temperature ($170^{\circ}C$). As a result, carbonation yield of the carbonized fibers was found to depend on the functions of the cross-linking ratio of the LDPE precursors.