저전력 및 고효율 면상발열체를 위한 피치기반 탄소종이 제조 및 특성

양재연,윤동호,김병석,서민강 한국복합재료학회 2018 Composites research Vol.31 No.6

In this work, phenolic resins containing conductive carbon fillers, such as, petroleum coke, carbon black, and graphite, were used to improve the surface heating elements by impregnating a pitch-based carbon paper. The influence of conductive carbon fillers on physicochemical properties of the carbon paper was investigated through electrical resistance measurement and thermal analysis. As a result, the surface resistance and interfacial contact resistivity of the carbon paper were decreased linearly by impregnating the carbon fillers with phenol resins. The increase of carbon filler contents led to the improvement of electrical and thermal conductivity of the carbon paper. Also, the heating characteristics of the surface heating element were examined through the applied voltage of 1~5 V. With the applied voltage, it was confirmed that the surface heating element exhibited a maximum heating characteristic of about 125.01oC(5 V). These results were attributed to the formation of electrical networks by filled micropore between the carbon fibers, which led to the improvement of electrical and thermal properties of the carbon paper. 본 연구에서는 면상발열체 특성을 향상시키기 위해 피치계 탄소종이에 전도성 탄소필러로 석유계 코크스, 카본블랙, 흑연을 페놀수지와 함께 함침시켰으며, 탄소종이에 함침된 탄소필러가 물리화학적 성질에 미치는영향을 전기적, 열적 특성 분석을 통해 고찰하였다. 그 결과, 면저항과 계면접촉저항이 선형적으로 감소하였으며, 탄소필러의 함량이 증가함으로써 전기전도도와 열전도도가 향상하였다. 또한, 탄소종이에 1~5 V 전압을 인가하였을 경우 탄소종이의 면상발열 특성을 관찰하였을 때 5 V 전압에서 최대 125.01oC로 발열 특성을 나타내었다. 이러한 결과는 탄소섬유 사이에 존재하는 미세공극이 채워짐으로써, 전기적 네트워크가 형성되어 전기적 및 열적특성이 향상되었기 때문이다.

Diminution of disposal cost and sequestration of carbon dioxide using paper making waste sludge

전치완,박상원,안지환,방준환,채수천 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.0

Pulp and paper mill waste sludges generated by primary pulping operation or waste paper making causes an environmental and disposal problem manufacturers of pulp and paper. The pulp and paper sludges digested with several acids for the purpose of dissociation of rigid form. The resulting leached solutions which contains many of calcium ions were treated with carbon dioxide gas for the purpose of mineral carbonation. The remained residuals below 20% composed to almost of organic material contained high calory can be used to energy resources. All the experimental process were proceeded in the media of aqueous solution with addition of amine in the state of open and closed system with carbon dioxide. The high efficiencies carbonation above 99% and high purity of calcium carbonate conversed their feature can be allowed to low cost disposal of paper making waste sludge, carbon dioxide diminution and reusing of calcium carbonate.

Efficiency Enhancement by pH Swing in Indirect Carbonation using Paper Sludge Ash and Acid

( Dami Kim ),( Myoung-jin Kim ) 한국폐기물자원순환학회(구 한국폐기물학회) 2015 한국폐기물자원순환학회 춘계학술발표논문집 Vol.2015 No.-

Carbon dioxide has steadily increased in atmosphere since the industrial revolution, and it is the main cause of the global warming. In this study, carbon dioxide is stored in the form of insoluble calcium carbonate through indirect carbonation using paper sludge ash (PSA) as a raw material and acids (acetic acid and hydrochloric acid) as solvents. Acid is very efficient to extract calcium from PSA, which is as high as 55%. However, since the pH of calcium extractant obtained using acid is as low as 6 and carbon dioxide is not present in the form of CO₃ ^2- at the low pH, carbonation reaction does not occur to form calcium carbonate. Sodium hydroxide, therefore, is added into the calcium extractant to increase pH up to 13. The amount of sodium hydroxide is calculated based on the equivalent of calcium in the extractant. Then, carbon dioxide is injected into the calcium extractant for 30 minutes at a flow rate of 0.05 L/min. The calcium extractant is prepared in advance using 40 g of PSA and 1L of 0.7 M acid, and 35mL of 50% sodium hydroxide is added into the extractant to adjust pH. During carbonation, liquid samples are taken at designated intervals to measure pH and calcium concentration. After the carbonation is completed, white solids are collected to dry at 105℃ for 12 hours, which weigh 30.0 g and 33.1 g from the extractants using acetic acid and hydrochloric acid, respectively. The white solids are found to be highly pure calcite by XRD analysis. Based on the solid mass, the amounts of carbon dioxide sequestrated in PSA are calculated to be 330.4 kg CO₂/ton PSA and 363.7 kg CO₂/ton PSA using acetic acid and hydrochloric acid as solvents, respectively.

Coffee-Driven Green Activation of Cellulose and Its Use for All-Paper Flexible Supercapacitors

Lee, Donggue,Cho, Yoon-Gyo,Song, Hyun-Kon,Chun, Sang-Jin,Park, Sang-Bum,Choi, Don-Ha,Lee, Sun-Young,Yoo, JongTae,Lee, Sang-Young American Chemical Society 2017 ACS APPLIED MATERIALS & INTERFACES Vol.9 No.27

<P>Cellulose, which is one of the most-abundant and-renewable natural resources, has been extensively explored as an alternative substance for electrode materials such as activated carbons. Here, we demonstrate a new class of coffee-mediated green activation of cellulose as a new environmentally benign chemical-activation strategy and its potential use for all-paper flexible supercapacitors. A piece of paper towel is soaked in espresso coffee (acting as a natural activating agent) and then pyrolyzed to yield paper-derived activated carbons (denoted as 'EK-ACs'). Potassium ions (K+), a core ingredient of espresso, play a viable role in facilitating pyrolysis kinetics and also in achieving a well-developed microporous structure in the EK-ACs. As a result, the EK-ACs show significant improvement in specific capacitance (131 F g(-1) at a scan rate of 1.0 mV s(-1)) over control ACs (64 F g(-1)) obtained from the carbonization of a pristine paper towel. All-paper flexible supercapacitors are fabricated by assembling EKACs/carbon nanotube mixture-embedded paper towels (as electrodes), poly(vinyl alcohol)/KOH mixture-impregnated paper towels (as electrolytes), and polydimethylsiloxane-infiltrated paper towels (as packaging substances). The introduction of the EKACs (as an electrode material) and the paper towel (as a deformable and compliant substrate) enables the resulting all-paper supercapacitor to provide reliable and sustainable cell perforinance as well as exceptional mechanical flexibility. Notably, no appreciable loss in the cell capacitance is observed after repeated bending (over 5000 cycles) or multiple folding. The coffee mediated green activation of cellulose and the resultant all-paper flexible supercapacitors open new material and system opportunities for eco-friendly high-performance flexible power sources.</P>

Effects of oxidized single-walled carbon nano tubes on carbon fiber papers as gas diffusion layers

김익규,박수진 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

In this work, PAN-based carbon fiber papers (CFPs) were prepared with various weight of oxidized single walled-carbon nanotubes. The electric properties, mechanical properties, surface energy and porosity of the resulting CFPs were investigated. The influences of the oxidized single wall carbon nano tubes contents on the electric and mechanical properties were also examined. The morphology of CFPs was observed using scanning electron microscopy and X-ray diffraction. The electric properties of the prepared CFPs were characterized by four-probe point method. The surface free energy was investigated using contact angle measurement of three liquid droplets. The porosity of prepared CPFs was examined by mercury porosimetry. The results indicate that amounts of oxidized single wall carbon nanotubes affect the electric and mechanical properties, and surface free energy of carbon fiber papers.

Efficiency Enhancement by pH Swing in Indirect Carbonation using Paper Sludge Ash and Acid

Dami Kim,Myoung-Jin Kim 한국폐기물자원순환학회 2015 한국폐기물자원순환학회 학술대회 Vol.2015 No.05

Carbon dioxide has steadily increased in atmosphere since the industrial revolution, and it is the main cause of the global warming. In this study, carbon dioxide is stored in the form of insoluble calcium carbonate through indirect carbonation using paper sludge ash (PSA) as a raw material and acids (acetic acid and hydrochloric acid) as solvents. Acid is very efficient to extract calcium from PSA, which is as high as 55%. However, since the pH of calcium extractant obtained using acid is as low as 6 and carbon dioxide is not present in the form of CO32- at the low pH, carbonation reaction does not occur to form calcium carbonate. Sodium hydroxide, therefore, is added into the calcium extractant to increase pH up to 13. The amount of sodium hydroxide is calculated based on the equivalent of calcium in the extractant. Then, carbon dioxide is injected into the calcium extractant for 30 minutes at a flow rate of 0.05 L/min. The calcium extractant is prepared in advance using 40 g of PSA and 1L of 0.7 M acid, and 35mL of 50% sodium hydroxide is added into the extractant to adjust pH. During carbonation, liquid samples are taken at designated intervals to measure pH and calcium concentration. After the carbonation is completed, white solids are collected to dry at 105℃ for 12 hours, which weigh 30.0 g and 33.1 g from the extractants using acetic acid and hydrochloric acid, respectively. The white solids are found to be highly pure calcite by XRD analysis. Based on the solid mass, the amounts of carbon dioxide sequestrated in PSA are calculated to be 330.4 kg CO2/ton PSA and 363.7 kg CO2/ton PSA using acetic acid and hydrochloric acid as solvents, respectively.

Low-Cost, High-Efficiency Conductive Papers Fabricated Using Multi-Walled Carbon Nanotubes, Carbon Blacks and Polyvinyl Alcohol as Conducting Agents

Kalam, Amir Abul,Bae, Joonho The Electrochemical Society 2015 ECS journal of solid state science and technology Vol.4 No.7

<P>Paper-based electronics or energy storage devices are emerging as next-generation technology. However, conducting agents for paper electrodes are prohibitively expensive at present. In this work, we demonstrate a facile and cost-effective way of converting sheets of commercial papers into high-performance conductive electrodes for supercapacitors. Multi-walled carbon nanotubes (CNTs), carbon blacks (CBs), and polyvinyl alcohol were successfully employed to fabricate conductive, flexible, bendable, disposable and foldable paper electrodes. The CNTs showed higher mass-specific capacitance (219 Fg<SUP>−1</SUP>), area-specific capacitance (9.8 mFcm<SUP>−2</SUP>), and energy density (30 Wh kg<SUP>−1</SUP>). Carbon blacks also demonstrated significantly large mass-specific capacitance (92 Fg<SUP>−1</SUP>) and area-specific capacitance (4.4 mFcm<SUP>−2</SUP>). This work is the first report on carbon-blacks-based paper electrodes of supercapacitors. Our method could provide a scalable way to realize paper-based electrode materials, which could find applications in next generation wearable devices.</P>

에너지 저장 장치 활용을 위한 간단한 폐지 탄화 방법 개발

손예닮,최석우,장윤정,김혜정 대한기계학회 2023 大韓機械學會論文集B Vol.47 No.11

전 세계 인구의 지속적인 성장으로 인해 다양한 종류의 종이에 대한 수요와 생산이 크게 증가했으며, 이로 인한 환경 오염 영향을 완화하기 위해 폐기물 관리 기술 발전 필요성이 증가했다. 본 연구에서는 폐지로부터 탄소 물질을 합성하기 위한 간단하고 빠른 탄화 방법을 개발했다. 합성한 폐지 유래 탄소의 물리적, 화학적 특성을 분석하고, 슈퍼커패시터 전극으로 제작하여 전기화학적 성능평가를 분석하고 에너지 저장 응용에 대한 가능성을 평가하였다. 제작한 탄소물질 중 MWC(microwave-assisted waste paper carbon)는 전기이중층 커패시턴스 특징을 가지고 있고 5 mV/s scan rate 에서 최대 119 F/g 의 중량 커패시턴스를 가진 것을 확인했다. 본 연구는 폐지를 탄소소재 생산에 재사용할 수 있는 대안을 제시함으로써 폐기물 관리 문제에 대한 해결책을 제공할 것으로 기대한다. The continuous growth of global population has led to a substantial increase in the demand for and production of various types of papers, which in turn, exacerbated the urgent need for waste management techniques to mitigate the environmental impact of these materials. Herein, we have developed a simple and rapid carbonization method for synthesizing valuable carbon materials from waste papers. Physical and chemical characteristics of the prepared waste paper derived carbons (WPDCs) were investigated. Next, the carbons were utilized in the fabrication of supercapacitor electrodes. Electrochemical performance of the WPDCs was systematically analyzed, and their feasibility for energy storage application was evaluated. Among the fabricated WPDCs, microwave-assisted waste paper carbon (MWC) exhibited electrical double layer capacitance and a maximum specific capacitance of 119 F/g at a scan rate of 5 mV/s. These findings provide a solution to the waste management problem by presenting an alternative way to reuse waste papers via the production of carbon materials.

탄소나노튜브로 개질된 탄소종이 기반 젖산산화효소 - 카탈레이즈 전극 제작 및 특성 분석

김창준,시키,셀바라잔 바르시니,양영일,김혁한 한국화학공학회 2023 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.61 No.4

This study aimed to investigate the impact of enhancing the electrode conductivity and mitigating the production of hydrogen peroxide - a by-product arising from lactate oxidation – on the performance of lactate electrodes. The electrical conductivity of the electrode was improved by modifying the surface of carbon paper with single-walled carbon nanotubes. Catalase was introduced to effectively eliminate the hydrogen peroxide produced during the lactate oxidation reaction. The carbon paper electrode, with simultaneous immobilization of both lactate oxidase and catalase, yielded a current 1.7 times greater than the electrode where only lactate oxidase was immobilized. The electrode in which lactate oxidase and catalase were co-immobilized on the surface of carbon paper modified with single-walled carbon nanotubes, produced a current of 171 μA, which was more than twice as much current as the carbon paper with only lactate oxidase immobilized. The optimized electrode showed a linear response up to lactate concentration of 20 mM, confirming that it can be used as a sensor electrode.

Porous carbon derived from waste corrugated paper with KOH-NaOH mixture and its adsorption property for methylene blue

Yang Mannan,Fang Changqing,Su Jian,Zeng Huilin,Lin Qilang 한국탄소학회 2023 Carbon Letters Vol.33 No.4

In this study, waste corrugated paper was used as carbon precursor with KOH-NaOH mixture (mole ratio was 51:49 and the melting point is 170 °C) as activator to prepare porous carbon at different reaction temperature and different mass ratio of KOH-NaOH mixture/waste corrugate paper fiber. The micro-morphology, pore structure information and composition of porous carbon were analyzed, and the formation mechanism of pores was investigated. The effect of activator amount and pyrolysis temperature on the morphology and structure of porous carbon were studied. The adsorption capacity of porous carbon was evaluated with the methylene blue as model pollutant. The effect of adsorbent amount, adsorption time and temperature on the adsorption performance of the porous carbon were analyzed. The maximum specific surface area is 1493.30 m2·g−1 and the maximum adsorption capacity of methylene blue is 518 mg·g−1. This study provides a new idea for efficient conversion and utilization of waste paper.