Comparisons of activated carbons produced from sycamore balls, ripe black locust seed pods, and Nerium oleander fruits and also their H2 storage studies

Osman ?ner,?nal Ge?gel,Tarık Avcu 한국탄소학회 2021 Carbon Letters Vol.31 No.1

Starting materials are very significant to produce activated carbons because every starting material has a different chemical structure; hence they affect the surface functional groups and surface morphologies of obtained activated carbons. In this study, sycamore balls, ripe black locust seed pods, and Nerium oleander fruits have been used as starting materials by ZnCl2 chemical activations for the first time. Firstly, activated carbons were obtained from these starting materials with ZnCl2 chemical activation by changing production conditions (carbonization time, carbonization temperature, and impregnation ratio) also affecting the structural and textural properties of the resultant activated carbons. Then, the starting materials and resultant activated carbons were characterized by utilizing diverse analysis techniques, such as TGA, elemental analysis, proximate analysis, BET surface areas, pore volumes, pore size distributions, N2 adsorption–desorption isotherms, SEM, FTIR spectra, and H2 adsorption isotherms. The highest surface areas were determined to be 1492.89, 1564.84, and 1375.47 m2/g for the activated carbons obtained from sycamore balls, ripe black locust seed pods, and N. oleander fruits, respectively. The yields of these activated carbons with the highest surface areas were calculated to be around 40%. As the carbonization temperature increased with sufficient ZnCl2 amount, N2 adsorption–desorption isotherms began to turn into Type IV isotherms given by mesoporous adsorbents with its hysteresis loops. Also, their hysteresis loops resembled Type H4 loop generally associated with narrow slit-like pores. Moreover, hydrogen uptakes under 750 mmHg at 77 K were determined to be 1.31, 1.48, and 1.24 wt% for the activated carbons with the maximum surface areas produced from sycamore balls, ripe black locust seed pods, and N. oleander fruits, respectively. As a result, the highest surface areas of the activated carbons with different structural properties produced in this study were obtained with different production conditions.

Pressure Effects on the Morphology Development of C/C Composites During Carbonization

Joo, Hyeok-Jong,Ryu, Seung-Hee,Ha, Hun-Seung 한국탄소학회 2001 Carbon Letters Vol.1 No.3

It is well known that the fabrication process of carbon/carbon composites is very complex. Above all, the carbonization process have major effect on the morphology development of carbon matrix. Carbon/carbon composites of 4-directional fiber preform were fabricated using the coal tar based pitch as a matrix precursor in this study. According to carbonization pressure of 1 bar, 100 bar, 600 bar, and 900 bar, morphological changes of cokes and matrix of composites were discussed. As the carbonization pressure increased to 600 bar, the flow pattern morphology of bulk mesophse was well developed. On the contrary, mosaic pattern morphology was found in case of 900 bar of carbonization pressure. It is confirmed that the carbonization pressure have profound effect on the degree of graphitization and crystal size of carbon matrix. Even in the highly densified carbon/carbon composites, large voids were still found in the matrix pocket region.

기본소득형 탄소세의 과세논리와 타당성 검토

김신언 한국세무사회 부설 한국조세연구소 2022 세무와 회계 연구 Vol.11 No.1

The purpose of the carbon tax is to significantly reduce carbon emissions, which have been the main cause of global warming. In addition to the carbon emission trading system(Emissions Trading System, ETS) and the carbon border tax system, the reason for introducing the carbon tax is that it directly imposes a burden on the individual people who ultimately consume fossil fuels and can reduce their use. However, as basic income researchers argue, the logic of the basic income carbon tax used to finance carbon dividends has some contradictions. First, the carbon tax is a tax that has a regulatory nature to reduce carbon emissions through a method that burdens the people. However, indiscriminate carbon dividends can be counterproductive to efforts to reduce carbon emissions. In addition, instead of paying carbon dividends to prevent tax resistance, government must let people expect that cheap alternative energy or reduction technology(CCUS) would be developed before 2050 which is able to let them sufficiently free from the burden of carbon tax. Therefore, carbon tax spending should be prioritized for expanding time-consuming and costly renewable energy support such as expanding hydrogen and electricity charging stations and developing technologies and building infrastructure to improve energy efficiency. Since the carbon tax inevitably imposes on the consumption of carbon-emitting products in order to maintain its regulatory character, the regressive problem of the consumption tax and the impact of rising prices on society as a whole should be thoroughly examined. However, basic income researchers have not provided reasonable evidence that the Switzerland carbon dividend, which is cited as a best practice by them can reduce carbon emissions. The Switzerland’case is not only able to be an objective comparison even within Europe but the effect on tax resistance was not also verified. When a new tax item is created, it is necessary to discuss the validity and efficiency of the collection procedure from the legislative debate stage. Currently, the basic income carbon tax bill not only has some parts to be reconsidered in tax law theory such as double taxation and delegation legislation issues, but also conflicts with the taxable provisions in the collection procedure at the time of taxation. There is no doubt that the groundbreaking methods presented by basic income researchers have helped to some extent to gain public attention to decrease carbon emission. However, they must convince people based on more rational and verified data that show the basic income-type carbon tax can reduce not only carbon emissions but also regressive problems including tax resistance. 탄소세는 지구온난화의 주범이 된 온실가스 배출량을 획기적으로 줄이는 데 그 목적이 있다. 탄소배출권거래제도와 탄소국경세라는 제도에 추가하여 탄소세까지 도입하는 이유는 화석연료를 최종 소비하는 국민 개개인에게 직접 부담을 주어 그 사용을 줄일 수 있다는 유인 효과 때문이다. 그러나 기본소득 연구자들이 주장하는 바와 같이 기본소득형 탄소세가 탄소 배당의 재원으로서 사용되면 규제적 성격을 가진 조세임에도 탄소배출의 감소 노력에 역효과를 발생시킬 수 있다. 또한, 조세저항을 막기 위해서는 탄소 배당이 아니라, 저렴한 대체에너지 또는 저감기술(CCUS)을 개발하여 탄소배출로부터 충분히 자유로워질 수 있는 청사진이 제시되어야 국민의 호응을 얻을 것이다. 이를 위해서는 탄소세 세수의 지출을 시간과 비용이 많이 소요되는 재생에너지원 확대와 수소 및 전기충전소 확충, 에너지 효율 향상을 위한 기술개발과 인프라 구축에 우선 사용하여야 할 것이다. 탄소세가 규제적 성격을 유지하기 위해서는 필연적으로 탄소배출 제품의 소비에 부과할 수밖에 없으므로 소비세가 가지는 역진성 문제와 물가상승으로 사회 전반에 미치는 영향을 충분히 심사숙고하여야 한다. 그러나 기본소득 연구자들이 우수 사례로 꼽는 스위스의 탄소 배당은 탄소배출을 감소시키는 데 도움을 주었다는 합리적 근거가 제시되지 않았고, 같은 유럽 내에서도 객관적인 비교 대상이 될 수 없을 뿐만 아니라 조세저항에 대한 효과도 검증된 것이 아니다. 탄소세라는 새로운 세목이 창설될 경우 징수절차의 타당성과 효율성 등에 대해서도 입법단계에서부터 반드시 심도 있는 논의가 필요하다. 현재 기본소득 탄소세 법안은 이중과세나 위임입법 문제를 비롯한 조세법 이론상 재검토되어야 할 부분이 존재할 뿐만 아니라 과세대상과 과세시기에서 징수 절차상 조문 간의 충돌이 발생한다. 탄소배출을 줄이기 위한 다양한 방법 중에서 그동안 기본소득 연구자들이 제시한 획기적인 방법은 조세법의 시야 확장에 일정 부분 역할을 하였다는 점에는 의심의 여지가 없다. 그러나 기본소득형 탄소세가 탄소 배출량 감소뿐만 아니라 역진성 문제와 조세저항을 줄일 수 있다고 제시한 논거들이 납득하기 어려운 점이 있으므로 보다 합리적이고 검증 가능한 연구결과를 제시하여야 할 것이다.

중국 탄소중립 지역별 이행여건 및 산업전략 분석

전유정,김수한 사단법인 코리아컨센서스연구원 2023 분석과 대안 Vol.7 No.2

Carbon neutrality, the international community's practical challenge in response to climate change, is becoming a key industrial strategy for the future development of nations. Despite concerns that China, as an economic powerhouse in the G2, may face challenges leading global climate change efforts due to its high-carbon-emitting industrial structure, it is leveraging carbon neutrality to enhance its industrial competitiveness. The Chinese government has formulated national policies for achieving carbon neutrality and detailed sector-specific plans to implement them. In particular, it aims to leverage carbon neutrality industrial strategies as a lever for adjusting the domestic industrial structure and fostering new industries, at the same time responding to international climate norms and external pressures. However, the effectiveness of carbon-neutral industrial strategies is expected to vary based on regional conditions such as economic and industrial levels. This article analyzes the regional conditions for implementing carbon neutrality in China, as well as the contents and characteristics of major industrial policies. Due to differing levels of economic development and industrial structures, significant variations in carbon emissions, size, emission sources, and efficiency are inevitable across regions. These disparities introduce diverse initial conditions and endogenous factors in pursuing carbon-neutral goals, limiting the direction and implementation of carbon-neutral industrial strategies favoring certain regions. In particular, the extent of policy autonomy granted to local governments regarding carbon neutrality implementation will influence the regional dynamics of central-local environmental governance. Consequently, it is crucial to emphasize regional monitoring alongside comprehensive national research to accurately navigate the path towards carbon neutrality in China. In summary, the article underscores the importance of understanding regional variations in economic development, industrial structure, and policy autonomy for successful carbon neutrality implementation in China. It highlights the need for regional monitoring and comprehensive national research to determine a more precise direction for achieving carbon neutrality.

Oxidation Resistant SiC Coating for carbon/carbon Composites

Joo, Hyeok-Jong,Lee, Nam-Joo,Oh, In-Seok 한국탄소학회 2003 Carbon Letters Vol.4 No.1

In this study, densified 4D carbon/carbon composites were made from carbon fiber and coal tar pitch through the process of pressure impregnation and carbonization and then followed by carbonization and graphitization. To improve the oxidative resistance of the prepared carbon/carbon composites, the surface of carbon/carbon composites was coated on SiC by the pack cementation method. The SiC coated layer was created by depending on the constitution of pack powder, and reaction time of pack-cementation. The morpology of crystalline and texture of these SiC coated carbon/carbon composites were investigated by XRD, SEM/EDS observation. So the coating mechanism of pack-cementation process was proposed. The oxidative res istance were observed through the air oxidation test, and then the optimal condition of pack cementation was found by them. Besides, the oxidative mechanism of SiC formed was proposed through the observation of SiC coated surface, which was undergone by oxidation test.

Role of Interface on the Development of Microstructure in Carbon-Carbon Composites

Dhakate, S.R.,Mathur, R.B.,Dhami, T.L.,Chauhan, S.K. Korean Carbon Society 2002 Carbon Letters Vol.3 No.4

Microstructure plays an important role in controlling the fracture behaviour of carbon-carbon composites and hence their mechanical properties. In the present study effort was made to understand how the different interfaces (fiber/matrix interactions) influence the development of microstructure of the matrix as well as that of carbon fibers as the heat treatment temperature of the carbon-carbon composites is raised. Three different grades of PAN based carbon fibres were selected to offer different surface characteristics. It is observed that in case of high-strength carbon fiber based carbon-carbon composites, not only the matrix microstructure is different but the texture of carbon fiber changes from isotropic to anisotropic after HTT to $2600^{\circ}C$. However, in case of intermediate and high modulus carbon fiber based carbon-carbon composites, the carbon fiber texture remains nearly isotropic at $2600^{\circ}C$ because of relatively weak fiber-matrix interactions.

2050 탄소중립 목표 실현을 위한 입법적 과제

채영근 인하대학교 법학연구소 2022 法學硏究 Vol.25 No.4

Korea is participating in the international community's response to climate change by joining the 1992 Convention on Climate Change, the Kyoto Protocol in 1997, and the Paris Agreement in 2015. Although it was classified as a developing country under the Kyoto Protocol and did not bear the obligation to reduce carbon emissions, Korea announced a voluntary reduction plan in 2009 called ‘30% reduction based on BAU by 2020’. Carbon emissions in 2020 increased by more than 100 million tonnes compared to 2009 as a result of not taking practical follow-up measures to reduce. However, in 2013, the Lee Myung-bak administration announced a plan to license seven new large-scale privately funded coal-fired power plants. The ETS, which was introduced as a major means of reducing carbon emissions in 2015, turned out generous allocation of emission rights to companies. These government policies demonstrate lack of sincerity of its intention to reduce carbon emissions. Since most of Korea's carbon emissions come from energy consumption, carbon reduction policies can be achieved through energy conversion, reorganization of energy-consuming industrial structures, and suppression of energy demand in all areas of society. However adhering to a low energy price policy, Korea is going in the opposite direction to reducing carbon emissions. In 2020, the Moon Jae-in administration again jumped on the bandwagon of the international community’s active movement to respond to the climate crisis, and declared that it would achieve carbon neutrality, which means zero net carbon emissions by 2050, and enacted the Framework Act on Carbon Neutrality in 2021 to legalize the goal of carbon neutrality. And as a mid- to long-term goal to achieve carbon neutrality by 2050, a 40% reduction in emissions compared to 2018 by 2030 was stipulated in the Enforcement Decree of the Act. The government has shown a stronger will than before by legislating the carbon neutral goal and intermediate goals in the legislation, but it is still criticized for not having any practical measures to achieve the goal. Rather than making practical and technical efforts to reduce carbon emissions, the Korean government has poured a lot of energy into only packaging slogans for “green growth.” Even if the Korean government’s policy itself is called ‘greenwashing’, what can be said? The Framework Act on Carbon Neutrality, which has been in effect since March 2022, covers a number of abstract policy measures to achieve carbon neutrality goals. The international community is responding in all directions in response to the climate crisis, and global companies are also accelerating the separation of growth and carbon for a sustainable economy. Traditional carbon-dependent businesses will increasingly lose ground. Large corporations in Korea, which have sensed the atmosphere of the times, are also making efforts to transform quickly. As Joseph Stieglitz said, “The problem is politics,” Korea is also becoming a situation where politics is holding back the economy. Politicians and the media are wasting precious time on political arguments rather than making efforts to draw a national consensus on the sharing of transition costs and serious discussions about the climate crisis. The climate crisis clock is now rapidly ticking down to six years. In this article, I first look at the current climate crisis situation and how the international community and global economic actors are moving in response to it, and argue that the implementation of the 2050 carbon neutral goal is not a matter of choice. In addition, the current status of carbon emissions in Korea, carbon policy, and the contents of the Carbon Neutral Framework Act are reviewed, and the Act is critically reviewed. Finally, practical policy measures and subsequent legislative directions needed to reduce carbon emissions are briefly presented. 우리나라는 1992년 기후변화협약, 1997년 교토의정서, 2015년 파리협정에 가입하는등 국제사회의 기후변화 대응에 참여는 하고 있으나, 온실가스 배출 저감을 위한 실천의지가 약하여 글로벌 기후위기의 주요 원인자가 되어가고 있다. 우리나라는 국제사회의적극적인 기후위기대응 움직임에 동참, 2050년까지 탄소 순배출량 제로를 의미하는 탄소중립을 달성하겠다는 선언을 하였고 2021년 탄소중립기본법을 제정하여 탄소중립 목표를 법률에 명문화하였다. 그리고 2050 탄소중립을 달성하기 위한 중장기목표로 2030 년까지 2018년 배출량대비 40% 감축을 동법시행령에 명문화하였다. 정부는 「탄소중립기본법」과 그 시행령에 탄소중립목표와 중간목표를 아예 법제화함으로써 종전보다 강한 의지를 보였으나, 정작 목표 달성을 위한 실질적인 조치는 없어 여전히 비판받고 있다. 우리나라의 탄소배출은 대부분 에너지소비에서 유래하는 바, 탄소저감 정책은 에너지전환, 에너지 다소비 산업구조의 개편, 사회전방위 에너지수요 억제를 통해 달성할 수 있을 것인데, 우리나라는 계속 경제에 미치는 영향을 이유로 낮은 에너지가격 정책을 고수하고있어 탄소배출 저감과 정반대 방향으로 가고 있다. 국제사회는 기후위기를 맞아 전방위적으로 대응하고 있고, 글로벌 기업들 역시 지속가능한 경제를 위해 성장과 탄소의 분리에 박차를 가하고 있다. 전통적인 탄소의존 사업들은 점점 더 설 자리가 없어지게 될 전망이다. 이러한 시대적 분위를 감지한 우리나라의 대기업들도 빠르게 변신을 위한 노력을 하고 있다. ‘문제는 정치야’라고 한 조지프 스티글리츠 말처럼, 우리나라 역시 정치가경제의 발목을 잡는 형국이 되어 가고 있다. 정치권과 언론은 기후위기에 대한 진지한토론과 전환비용 분담에 대한 국민적 합의도출을 위한 노력을 기울이기 보다는 정치공학적 이전투구에 아까운 시간을 허비하고 있다. 기후위기시계는 이제 6년으로 빠르게 줄어들고 있다. 이 글에서는 먼저 현재의 기후위기 상황과 이에 대한 국제사회 및 글로벌경제주체들이 어떻게 움직이고 있는지 살펴보고 2050 탄소중립 목표의 실천이 선택의문제가 아님을 논증한다. 그리고 우리나라의 탄소배출 현황과 탄소정책 및 탄소중립기본법의 주요 내용을 살펴보고 동법률에 대하여 비판적으로 검토한다. 마지막으로 탄소배출감축을 위해 필요한 실질적인 정책수단들과 후속 입법 방향을 간략히 제시하고자 한다.

Perylenetetracarboxylic dianhydride의 탄소전구체로의 응용

권웅,김창규,한민우,정의경 한국섬유공학회 2020 한국섬유공학회지 Vol.57 No.5

This study aims to investigate the application of perylenetetracarboxylic dianhydride (PTCDA), which is also known as C.I. Pigment Red 224 (PR224), as a carbon precursor. PTCDA has a stacking structure and planarity, thereby forming a crystal structure and good thermal stability. Moreover, PTCDA has a very high theoretical elemental carbon content of 73.47%, which suggests that its maximum theoretical carbon yield is more than 70%. Therefore, PTCDA was selected as a carbon precursor and compared with coal-tar pitch and petroleum pitch, which are carbon precursors with high carbon yield and excellent carbon crystallinity after carbonization. The initial decomposition temperature of PTCDA was 240–328 °C higher than that of the pitches, suggesting that the thermal stability of PTCDA is better than that of the other pithces. After carbonization, the graphite (002) interplanar distance (d002) of carbonized PTCDA (C-PTCDA) was 3.54 Å, which was similar to that of the pitch-based carbons. The crystal size (Lc) was the largest among the prepared carbons with 30.03 Å. The ID/IG ratio of C-PTCDA was 2.12, which was the lowest value among the prepared carbons. The 2D peak of C-PTCDA was observed at 2720 cm-1, suggesting the least disordered graphite structure. Therefore, we believe that PTCDA has excellent potential for use as a carbon precursor for highly ordered carbon materials.

Preparation and characterization of carbon/carbon composites with coal-tar pitch based carbon felt

양재연,고재경,김병석,서민강 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

Carbon/carbon (C/C) composites are structural materials for use in structural applications at elevated temperatures due to the combination of their excellent mechanical properties and lower thermal expansion coefficient. Mechanical properties of the C/C composites depend on the matrix precursor and type of the carbon fibers used. Among these, the factor concerning carbon fibers plays an important role. In this study, C/C composites were made using type of the carbon fibers and resoltype phenolic resins. And effects of carbon fiber types on mechanical properties of the C/C composites were investigated by the three-point short-beam test according to the flexural strength and fractured C/C composites were examined under a scanning electron microscope (SEM).

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.