콜타르로부터 탄소섬유 제조를 위한 프리커서용 석탄계 핏치의 제조

고효준,박창욱,조효행,유미정,김명수,임연수,Ko, Hyo Joon,Park, Chang Uk,Cho, Hyo Hang,Yoo, Mi Jung,Kim, Myung-Soo,Lim, Yun-Soo 한국재료학회 2013 한국재료학회지 Vol.23 No.5

Coal tar is the primary feedstock of premium graphitizable carbon precursor. Coal tars are residues formed as byproducts of thermal treatments of coal. Coal tar pitches were prepared through two different heat treatment schedules and their properties were characterized. One was prepared with argon and oxidation treatment with oxygen; the other was prepared with oxygen treatment at low temperature and then argon treatment at high temperature; both used coal tar to prepare coal tar pitches. To modulate the properties, different heat treatment temperatures ($300{\sim}400^{\circ}C$) were used for the coal tar pitches. The prepared coal tar pitches were investigated to determine several properties, such as softening point, C/H ratio, coke yield, and aromaticity index. The coal tar pitches were subject to considerable changes in chemical composition that arose due to polymerization after heat treatment. Coal tar pitch showed considerable increases in softening point, C/H ratio, coke yields, and aromaticity index compared to those characteristics for coal tar. The contents of gamma resin, which consists of low molecular weight compounds in the pitches and is insoluble in toluene, showed that the degree of polymerization in the pitches was proportional to C/H ratio. Using an oxidizing atmosphere like air to prepare the pitches from coal tar was an effective way to increase the aromaticity index at relatively low temperature.

Pyrolyzed Fuel Oil/Coal-tar 혼합원료의 열중합 반응에 따른 Pitch 제조 특성

이은별 ( Eunbyul Lee ),김형기 ( Hyeong Gi Kim ) 한국공업화학회 2020 공업화학 Vol.31 No.3

본 연구에서는 PFO와 Coal-tar의 구조와 열 중합 거동 분석을 통해 PFO와 Coal-tar으로 구성된 혼합 원료의 피치 합성 간 제조 특성을 확인하였다. 원소분석과 FT-IR 분석을 통해, PFO와 Coal-tar 각각 0.355, 0.818로 방향족화도 수치를 확인하였다. 또한, PFO와 Coal-tar의 열중량 분석을 통해 질량 감소곡선의 차이를 확인하였으며, 이러한 현상은 방향족 화도와 관능기 함량에 따른 구조적 안정성에 기인한 것으로 판단된다. 피치 제조 특성은 PFO를 원료로 사용한 피치가 혼합원료로부터 제조된 피치보다 평균적으로 낮은 수율과 높은 연화점을 보임을 확인하였다. 특히 유사한 연화점을 가지는 P360 (138.5 ℃)과 B420 (141.4 ℃)을 비교하였을 때, 두 피치의 탄화수율은 각각 29.89, 49.03 wt%로 Coal-tar가 혼합된 경우 약 20 wt% 향상됨을 확인하였다. 이러한 결과는 다량의 알킬기를 포함하여 높은 피치 중합 반응성을 가지는 PFO와 높은 열적 안정성을 가지는 Coal-tar의 혼합에 기인한 것으로 판단된다. In this study, blended feedstock derived pyrolyzed fuel oil (PFO) and coal-tar was prepared to produce a pitch by thermal polymerization reaction for manufacturing artificial graphite materials. The aromaticity value of 0.355 and 0.818 was obtained for PFO and coal-tar, respectively. In addition, PFO and coal-tar exhibited the difference tendency of weight loss curve for thermogravimetric analysis, which is related to the structural stability depending on the aromaticity and functional groups. The production characteristics confirmed that the pitch derived PFO showed lower production yield and higher softening point than that using blended feedstock. In particular, when comparing P360 (138.5 ℃) and B420 (141.4 ℃) having similar softening points, the production yields of both pitches exhibited 29.89 and 49.03 wt%, respectively. This is mainly due to the blending of PFO and coal-tar having high pitch polymerization reactivity including a large amount of alkyl groups and coal-tar having high thermal stability. This phenomenon indicated that the increased production yield is because of a synergic effect of both the high reactivity of PFO and thermal stability of coal-tar.

콜타르 피치를 취급하는 근로자의 광독성 피부질환

정철,임현술,김두희,성열오,Jung, Cheol,Lim, Hyun-Sul,Kim, Doo-Hie,Sung, Yeol-Oh 대한예방의학회 1997 예방의학회지 Vol.30 No.1

Interview survey and dermatological examination have been performed to investigate the health problems of workers continuously exposed to coal-tar pitch. The phototoxicity of coal-tar pitch was confirmed by the photopatch tests for six healthy adults. The main results are followings; 1. There was no special history of allergic diseases in both the exposed and non-exposed group. 2. The frequency of the phototoxic dermatosis and the coal-tar acne in the exposed group was significantly greate.(p<0.05) than that of the control group. In the exposed group, the phototoxic dermatosis and the coal-tar acne were observed in nine workers(90%) and seven workers(70%), respectively. However, those, disease were not observed in the control group. 3. Five results(83%) were positive to the photopatch test for coal-ta. pitch 48 hours after UVA irradiation. But the lesion was subsiding 72 hours after UVA irradiation. 4. Malignant cancers were not reported among workers ever exposed to coal-tar pitch. In conclusion, it appears that workers exposed to coal-tar pitch have high risks of phototoxic dermatosis and coal-tar acne. A health policy should be provided to prevent phototoxic dermatosis among coal-tar pitch workers. More studies are required to determine malignancy.

열분해유/콜타르 혼합비가 피치계 활성탄의 수율 및 물성에 미치는 영향

유태웅 ( Tae Ung Yoo ),서상완 ( Sang Wan Seo ),임지선 ( Ji Sun Im ),이수홍 ( Soo Hong Lee ),송우진 ( Woo Jin Song ),강석창 ( Seok Chang Kang ) 한국공업화학회 2024 공업화학 Vol.35 No.2

피치계 활성탄의 수율 향상을 위해 열분해유와 콜타르를 혼합하여 피치를 합성하고, 합성된 피치를 물리적 활성화하여 활성탄을 제조하였다. 피치는 콜타르를 열분해유 대비 0~20%로 달리하여, 380~420 ℃에서 3 h 반응하여 합성하였다. 합성된 피치는 80~260 ℃ 사이의 연화점을 가졌고, 10~40% 범위의 수율을 나타냈다. 모든 합성온도에서 콜타르 혼합비율이 증가할수록 수율이 증가하고, 연화점이 감소함을 확인하였다. 합성된 피치 중 연화점이 230~260 ℃ 사이의 피치를 선정하여 물성을 고찰하였다. 열분해유만으로 제조된 피치에 비해 콜타르가 함유된 피치가 저비점에서 휘발분이 많고, 잔탄량이 높았다. 이는 콜타르와 열분해유의 조성에 따른 차이로, 방향족 성분이 많은 콜타르와 지방족 성분이 많은 열분해유의 영향임을 확인하였다. 선정된 피치를 관형 반응기에서 950 ℃까지 승온하고, 1 h 동안 수증기로 물리적 활성화하였다. 콜타르가 포함된 활성탄이 열분해유만으로 제조된 활성탄에 비해 높은 수율과 미세기공율을 나타냈다. 본 연구에서는 피치 원료 혼합에 의한 활성탄 수율 증가 효과를 확인하고, 콜타르 혼합 비율에 따른 물리적 활성화 특성을 고찰하였다. In order to produce high-yield pitch-based activated carbon, pitch was synthesized by blending pyrolysis fuel oil (PFO) and coal-tar. Pitch was synthesized by varying the amount of coal-tar from 0~20% compared to PFO and reacting at 380~420 ℃ for 3 h. The synthesized pitch had a softening point between 80 and 260 ℃, and yields ranged from 10 to 40%. At all synthesis temperatures, as the coal-tar blending ratio increased, the yield increased and the softening point decreased. After considering the selected pitches (softening points: 230~260 ℃), pitches containing coal-tar were more volatile at a low boiling point and had a higher residual carbon content. This is a difference in the composition of coal-tar and PFO, and it was confirmed that coal-tar has a lot of aromatics and PFO has a lot of aliphatics. The selected pitch was heated to 950 ℃ in a tubular reactor and physically activated with steam for 1 hour. Activated carbon containing coal-tar showed higher yield and microporosity compared to only PFO. In this study, the effect of increasing activated carbon yield by blending pitch raw materials was confirmed, and the physical activation characteristics according to the coal-tar mixing ratio were examined.

Effect of the pre‑treated pyrolysis fuel oil: coal tar pitch ratio on the spinnability and oxidation properties of isotropic pitch precursors and the mechanical properties of derived carbon fibers

Jinchang Liu,Hiroki Shimanoe,Jong‑Eun Choi,Seunghyun Ko,Young‑Pyo Jeon,Koji Nakabayashi,Jin Miyawaki,Seong‑Ho Yoon 한국탄소학회 2019 Carbon Letters Vol.29 No.2

Pitch precursors affording excellent spinnability, high-level oxidation-resistance, and good carbonization yields were prepared by bromination–dehydrobromination of various ratios of pyrolyzed fuel oil and coal tar pitch. The pitches exhibited spinnabilities that were much better than those of pitches prepared via simple distillation. A pitch prepared using a 1:2 ratio of fuel oil and coal tar pitch exhibited the best tensile strength. Pitch fibers of diameter 8.9 ± 0.1 μm were stabilized at 270 °C without soaking time after heating at a rate of 0.5 °C/min and carbonized at 1100 °C for 1 h after heating at 5 °C/min. The resulting carbon fibers exhibited a tensile strength, elongation, Young’s modulus, and average diameter of 1700 ± 170 MPa, 1.6 ± 0.1%, 106 ± 37 GPa, and 7.1 ± 0.2 μm, respectively.

석탄계 타르의 열처리 중 압력변화에 따른 변성 콜타르 핏치의 미세구조 및 물성 변화

고효준,정성모,한지훈,박창욱,김명수,임연수,Ko, Hyo Joon,Chung, Sung Mo,Han, Ji Hoon,Park, Chang Uk,Kim, Myung-Soo,Lim, Yun-Soo 한국재료학회 2014 한국재료학회지 Vol.24 No.6

Coal-tar pitch, a feedstock which can be heat-treated to create graphite, is composed of very complex molecules. Coal-tar pitch is a precursor of many useful carbon materials (e.g., graphite, carbon fibers, electrodes and matrices of carbon/carbon composites). Modified coal-tar pitch (MCTP) was prepared using two different heat-treatment methods and their properties were characterized and compared. One was prepared using heat treatment in nitrogen gas; the other was prepared under a pressure of 350 mmHg in air. The MCTPs were investigated to determine several properties, including softening point, C/H ratio, coke yield, formation of anisotropic mesophase and viscosity. The MCTPs were subject to considerable changes in chemical composition due to condensation and polymerization in the used-as-received coal-tar pitch after heat-treatment under different conditions. The MCTPs showed considerable increases in softening point, C/H ratio, and coke yield, compared to those of as-received coal-tar pitch. The MCTP formed by heat-treatment in nitrogen showed isotropic phases below $350^{\circ}C$ for 1 h of soaking time. However, MCTP heat-treated under high pressure (350 mmHg) showed isotropic phases below $300^{\circ}C$, and showed anisotropic phases above $350^{\circ}C$, for 1 h of soaking time. The viscosity of the MCTPs increased with increase in their softening points.

환경친화적 콜탈에나멜의 개발

이진욱,이의수,이명천 동국대학교 산업기술연구원 1998 산업기술논문집 Vol.11 No.-

콜탈에나멜의 수송관 코팅제로서의 요구물성을 충족시키면서, 유해한 fume의 발생을 최소화하는 환경 친화적인 저 휘발성 콜탈에나멜을 개발하였다. 이는 기존의 coal tar enamel의 주원료인 coal tar를 사용하지 않고, 휘발분의 유출량이 상대적으로 적은 물성을 가진 원료인 heavy oil, middle pitch, coal만의 혼합으로 가능하였으며, 제품을 휘발분 실험한 결과 휘발분이 평균 36.7%가 낮은 환경 친화적인 제품을 만들 수 있었다. 저 휘발성 콜탈에나멜을 제조시 얻은 물성 data로부터 heavy oil과 pitch의 투입비(%), coal의 투입량(weight%), 그리고 원료 heavy oil의 ASTM 유출량을 독립변수로 하여 연화점과의 상관관계식을 도출하였으며, 이로부터 얻어지는 연화점으로부터 침입도를 예측할 수 있는 관계식을 유도하였다. 이들 관계식은 향후 신제품 개발시, 공정을 최적화시키기 위한 원료 배합비의 결정을 위한 기준으로 사용될 수 있다. For easement of working environmental problem we developed low fume coal tar enamel(CTE), which is made by mixing of low volatile materials, i.e heavy oil, middle pitch and coal. The new CTE product not only meets the required physical properties as the protective coatings for steel pipe but has volatilities by average 36.7% lower than existing CTE. As a guide for manipulation of operation conditions we derived a correlated equation of softening point from independent manufacturing variables such as projection ratio of heavy oil and pitch(%), projection weight (%), and ASTM effluent quality of heavy oil. And we also derived a correlated equation for prediction of penetration point from softening point. These equations can be used to predict the optimal mixing ratio of raw materials

Controlling spinning pitch property by tetrahydrofuran‑soluble fraction of coal tar pitch co‑carbonization with petrolatum

Wei Jiang,Guosong Ni,Pingping Zuo,Shijie Qu,Yunmei Li,Hongxian Niu,Wenzhong Shen 한국탄소학회 2019 Carbon Letters Vol.29 No.5

Isotropic pitch-based carbon fiber was successfully prepared from tetrahydrofuran-soluble fraction of coal tar pitch cocarbonization with petrolatum by air-blowing. The effects of reaction temperature and time, amount of petrolatum added on the composition and spinning properties of resultant pitches were investigated. It indicated that petrolatum could effectively improve the softening point, aromaticity, hydrogen content and molecular weight of the resultant pitches by promoting cross-linking and dehydrogenation polymerization reactions at low air-blowing temperature. Moreover, more aliphatic and naphthenic structures had been introduced into resultant pitches as addition of petrolatum and also inhibited the generation of quinoline-insoluble particles. The obtained green fibers were facile to be stabilized and carbonized and the resultant carbon fibers showed fully isotropic and finer, uniform diameter with smooth surface and higher tensile strength of up to 0.92 GPa. It provided a facile chemical modification method for isotropic pitch-based carbon fiber production.

탄소/탄소 복합재 매트릭스 전구체로서의 메조페이스 핏치의 제조 및 특성에 관한 연구

정현진,임연수 한국세라믹학회 1996 한국세라믹학회지 Vol.33 No.12

A study on mesophase pitch as a matrix precursor of carbon fiber reinforced carbon (C/C) composite has been recently presented. This study is concerned with the production of mesophase pitch as matrix precursors for C/C composite from coal tar pitch. A commercial coal tar pitch was heat-treated at 25$0^{\circ}C$ for 2 hours to remove low molecular weight fraction from the pitch then increasing the temperature of the pitch to between 350~45$0^{\circ}C$ to produce mesophase pitch. The pitch was continuously stirred during this time and nitrogen gas was continuously bubbled through the pitch. Spherical and bulk mesophases were formed in the pitch after heat-treatment,. Parent and mesophae pitches were characterized by elemental analysis coke yield solubi-lity in tetrahydrofuran and hexane and an optical microscopy to measure the mesiophase content. It was neces-sary to produce C/C composite that a mesophase pitch with about 30-40 vol% mesophase spherulites can be infiltrated into a fiber preform without a filter effect as a matrix precursor conditions. This condition was satisfied with mesophase pitch heat treated at 40$0^{\circ}C$ for 2 hours. The other heat treatment conditions showed the nuclei of mesophase or bulk mesophae which were not satisfied with the matix precursor condition.

Modification of isotropic coal-tar pitch by acid treatments for carbon fiber melt-spinning

Yoo, Mi Jung,Ko, Hyo Jun,Lim, Yun-Soo,Kim, Myung-Soo 한국탄소학회 2014 Carbon Letters Vol.15 No.4

In this work, thermal treatment accompanied with different acid treatments was applied to a commercial coal tar pitch (CTP) to obtain a spinnable precursor pitch for carbon fiber. In the case of thermal treatment only, a relatively high reaction temperature of between 380˚C and 400˚C was required to obtain a softening point (SP) range of 220˚C-260˚C and many meso-phase particles were created during the application of high reaction temperature. When nitric acid or sulfuric acid treatment was conducted before the thermal treatment, the precursor pitch with a proper SP range could be obtained at reaction temperatures of 280˚C-300˚C, which were about 100˚C lower than those for the case of thermal treatment only. With the acid treatments, the yield and SP of the precursor pitch increased dramatically and the formation of meso-phase was suppressed due to the lower reaction temperatures. Since the precursor pitches with acid and thermal treatment were not spinnable due to the inhomogeneity of properties such as molecular weight distribution and viscosity, the CTP was mixed with ethanol before the consecutive nitric acid and thermal treatments. The precursor pitches with ethanol, nitric acid, and thermal treatments were easily spinnable, and their spinning and carbon fiber properties were compared to those of air blowing and thermal treated CTP.