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Carbonization behavior of the low molecular weight components in petroleum based pitch
최종은,고승현,이철위,전영표 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.0
Pyrolysis fuel oil (PFO) is a promising candidate to be utilized as petroleum pitches for carbon materials. We have researched effects of low molecular weight components in PFO onto carbonization behavior of resulting pitches prepared by thermal treatments. Molecular weight distribution of PFO has been selectively adjusted by series of pre-heat treatment methods. After pre-treatment, the PFO has been synthesized by thermal polymerization under various conditions. Once the pitches were synthesized, carbonization experiments of the pitches were conducted, and resulting materials were characterized according to the traditional manner; softening point measurement, EA, NMR, MALDI-TOF analysis. Molecular weight distributions and chemical structure were investigated by MALDI-TOF and solid-state (13)C-NMR. Thermal properties and C/H atomic ratio were measured by thermogravimetric analysis and elemental analysis.
Preparation of Cost-Competitive Impregnating Pitch from Petroleum Residue
최종은,고승현,장혁철,이철위,전영표 한국공업화학회 2016 한국공업화학회 연구논문 초록집 Vol.2016 No.1
Impregnation is one of the most important steps to produce high quality synthetic graphite by densifying graphite block or electrode. A typical resource to synthesize impregnating pitch is coal-tar, which has relatively higher impurities, such as sulfur, nitrogen, ash, and etc., than petroleum residue. Due to such impurities, several purification steps are necessary to synthesize impregnating pitch from coal-tar. As a precursor for impregnating pitch synthesis, we have examined pyrolysis fuel oil (PFO), one of the petroleum residues which already well purified through the petroleum refining processes. We also have applied a simple thermal polymerization technique under various conditions to minimize processing cost. As results, we obtained impregnating pitches with softening point (TSP) between 110 and 130°C, and the resulting pitches were characterized by analytical techniques.
고승현,최종은,이철위,전영표 한국공업화학회 2017 Journal of Industrial and Engineering Chemistry Vol.54 No.-
A modified oxidative thermal treatment was developed to increase the softening point of a pitch precursor while minimizing the pitch yield loss. An O2/N2 mixed gas was used as the reaction gas, and the softening point and pitch yield variations were measured at different O2 concentrations. As a result, when softening point increased from 130 to 249 C, the pitch yield remained almost constant (only 0.6% drop). Structural analysis performed via MALDI-TOF, FTIR, and 1H and 13NMR showed that condensation reaction between pitch molecules in the presence of O2-containing gas followed a different mechanism depending on the O2 concentration. In addition, the precursors were spun into pitch fibers and carbonized at 1100 C. During the spinning, they exhibited excellent spinnability without breakage for more than 10 min of spinning. The obtained carbon fibers showed high tensile strengths comparable to that of a commercial isotropic-pitch-derived carbon fiber (0.83 GPa). The current study showed that the modified thermal treatment is useful for the preparation of cost-competitive pitch precursors suitable for carbon fiber production.
고승현,최종은,이철위,전영표 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1
We have studied effects of nitrogen flow rate on mesohpase pitch synthesis from a type of petroleum residue, pyrolysis fuel oil (PFO). A distillation method was applied to synthesize petroleum pitch; heat treatments were performed in a 0.5 L autoclave type of reactor under nitrogen gas flow and effects of temperature were studied. To investigate the influence of nitrogen flow rate on growth rate of mesophase sphere, gas flow rate was preciously controlled from 100 to 800 cm<sup>3</sup>/min. The resultant pitches were characterized by using a polarized light microscopy and a thermogravimetric analysis instrument. Additional pitch characteristics such as softening points and quinoline insoluble contents of the experimental pitches were also examined.
고승현,최종은,이철위,전영표 한국탄소학회 2020 Carbon Letters Vol.30 No.1
Spinnable mesophase pitch precursor containing more than 98% mesophase content was successfully prepared from FCC-DO (fuid catalytic cracking-decant oil) without hydrogenation or catalytic reaction. The preparation method involved thermal condensation, vacuum treatment, and annealing treatment. Petroleum mesophase pitch-based carbon fbers are produced by melt spinning of pitch precursors, followed by stabilization and carbonization. The resulting carbon fber exhibited good mechanical performances up to tensile strength of 2.1 GPa and tensile modulus of 212 GPa, with strain-to-failure higher than 1.0%. These properties ensuring that the automotive grade carbon fbers can be successfully prepared from FCC-DO derived petroleum mesophase pitches through the cost-competitive processes.
고승현,최종은,하승재,이철위,전영표 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0
Mesophase pitch is one of the key precursors for the preparation of high performance carbon materials. In this study, we have conducted oxidative thermal treatment of fluidized catalytic cracking-decant oil (FCC-DO), and investigated its effect on the formation of mesophase pitch. The oxidative treatment was performed at temperatures between 200 °C and 300 °C with air-blowing. And the resulting products were analyzed by Fourier transform infrared spectroscopy (FTIR), elemental analyzer (EA), and polarized-light microscopy. As a result, it was found that the oxidative treatment definitely facilitated the formation of mesophase pitch.
Effects of SO2 gas adsorption properties of N2 plasma treaed activated carbon fiber
배병철,최종은,이철위,이영석,임지선 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.0
The mechanisms of the SO2 gas adsorption properties of activated carbon fibers were studied based on surface treatment. The surfaces of the activated carbon fibers (ACFs) were modified by plasma treatment using N2 gas to enhance the adsorption of SO2 by the fibers based on the effects of the nitrogen functional groups introduced on the surface. Nitrogen functional groups were effectively introduced onto the surfaces of the ACFs based on the semi-introduction with SO2 molecules, and they attached themselves to the pores of the ACFs as the flow rate of N2 gas increased. The nitrogen functional groups, on the surfaces of the ACFs played an important role in guiding SO2 into the micropores via the attractive forces experienced by the electrons in the SO2 molecules.
Histamine - gammaglobulin 으로 치료한 천식환아에서의 치료전후의 혈청 IgE , IgG 및 혈중 총호산구 변화
김규언,김학용,최종위,이기영 대한천식알레르기학회 1984 천식 및 알레르기 Vol.4 No.1
Histaminemaglobulin is used as nonspecific immunotheraphy to the patients who can not be hyposensitized with specific allergens due to negaive skin test and who are infants or very young qhildren with asthma. Fourtne children with asthm a were studied and their mean age were 6 2/12 years. Serum levels of IgE, IgG and total eosinophil count were me asured after 9 subcutaneous injections at 10 days interval and the levels were compared with those before administration. IgE (238.17 + 42.65 U/ml), IgG (782.76 + 37.68 mg/dl) and total eosinophil count (498.41 + 83.14/mm) before therapy and IgE (195.68 + 34.15 U/ml), IgG (814.44 + 38.42 mg/dl), total eosinophil count (411.37 + 62.55 mm) after therapy showed no significant change (P > 0.05). Those changes among the patients who showed improving tendency (26 patients, 63.4%) and those who showed no response (15 patients, 36.6%) also were not significant (P > 0.05). It is suggested that the evaluation of the effectiveness of histamine-gammaglobulin therapy can be based upon clinical symptoms and that the changes of serum immunoglobulin levels and total eosinophil count have no aignificance.