• 제목/요약/키워드: thermochemical conversion

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Studying Thermochemical Conversion of Sm2O3 to SmCl3 using AlCl3 in LiCl-KCl Eutectic Melt

  • Samanta, Nibedita;Chandra, Manish;Maji, S.;Venkatesh, P.;Annapoorani, S.;Jain, Ashish
    • Journal of Electrochemical Science and Technology
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    • 제13권2호
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    • pp.279-291
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    • 2022
  • In this report the thermochemical conversion of Sm2O3 to SmCl3 using AlCl3 in LiCl-KCl melt at 773 K is discussed. The final product was a mixture of SmCl3, Al2O3, unreacted Sm2O3 and AlCl3 in the chloride melt. The electrochemical attributes of the mixture was analyzed with cyclic voltammetry (CV) and square wave voltammetry (SWV). The crystallographic phases of the mixture were studied with X-ray diffraction (XRD) technique. The major chemical conversion was optimized by varying the effective parameters, such as concentrations of AlCl3, duration of reaction and the amount of LiCl-KCl salt. The extent of conversion and qualitative assessment of efficiency of the present protocol were evaluated with fluorescence spectroscopy, UV-Vis spectrophotometry and inductively coupled plasma atomic emission spectroscopy (ICP-AES) studies of the mixture. Thus, a critical assessment of the thermochemical conversion efficiency was accomplished by analysing the amount of SmCl3 in LiCl-KCl melt. In the process, a conversion efficiency of 95% was achieved by doubling the stoichiometric requirement of AlCl3 in 50 g of LiCl-KCl salt. The conversion reaction was found to be very fast as the reaction reached equilibrium in 15 min.

미세조류 탈지세포잔류물의 미생물 배양 및 바이오에너지 생산으로의 재활용 (Recycling of Lipid-extracted Algae Cell Residue for Microorganisms Cultivation and Bioenergy Production)

  • 당낫민;이기세
    • 공업화학
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    • 제32권5호
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    • pp.487-496
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    • 2021
  • Microalgae is one of the promising biodiesel feedstock with high growth rates compared to those of terrestrial oil crops. Despite its numerous advantages, biodiesel production from microalgae needs to reduce energy demand and material costs further to go to commercialization. During solvent extraction of microalgal lipids, lipid-extracted algae (LEA) cell residue is generated as an organic solid waste, about 80-85% of original algal biomass, and requires an appropriate recycling or economic disposal. The resulting LEA still contains significant amount of carbohydrates, proteins, N, P, and other micronutrients. This review will focus on recent advancement in the utilization of LEA as: (i) utilization as nutrients or carbon sources for microalgae and other organisms, (ii) anaerobic digestion to produce biogas or co-fermentation to produce CH4 and H2, and (iii) conversion to other forms of biofuel through thermochemical degradation processes. Possible mutual benefits in the integration of microalgae cultivation-biodiesel production-resulting LEA with anaerobic digestion and thermochemical conversion are also discussed.

바이오매스 에너지화: 청정 연소를 위한 신재생 연료 생산 공정 (Biomass to Energy: Renewable Fuel Production Processes for Clean Combustion)

  • 정재용;김영두;양원;이은도;정수화;방병열;문지홍;황정호;장원석
    • 한국연소학회:학술대회논문집
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    • 한국연소학회 2015년도 제51회 KOSCO SYMPOSIUM 초록집
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    • pp.285-285
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    • 2015
  • Utilization of biomass as a substitute fuel for conventional energy systems have been grown larger everyday in the world. In particular, co-firing of biomass in a large coal power plant are common in Korea after the introduction of RPS since 2012, and the application of biomass-derived fuel is now spreading to district heating and power, industrial energy supply, and transportation sectors. For biomass to energy, appropriate conversion process is needed to satisfy the fuel requirements of a specific energy system. In this study, various kinds of thermochemical conversion technologies will be presented for renewable fuel productions from biomass.

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Uranium thermochemical cycle used for hydrogen production

  • Chen, Aimei;Liu, Chunxia;Liu, Yuxia;Zhang, Lan
    • Nuclear Engineering and Technology
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    • 제51권1호
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    • pp.214-220
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    • 2019
  • Thermochemical cycles have been predominantly used for energy transformation from heat to stored chemical free energy in the form of hydrogen. The thermochemical cycle based on uranium (UTC), proposed by Oak Ridge National Laboratory, has been considered as a better alternative compared to other thermochemical cycles mainly due to its safety and high efficiency. UTC process includes three steps, in which only the first step is unique. Hydrogen production apparatus with hectogram reactants was designed in this study. The results showed that high yield hydrogen was obtained, which was determined by drainage method. The results also indicated that the chemical conversion rate of hydrogen production was in direct proportion to the mass of $Na_2CO_3$, while the solid product was $Na_2UO_4$, instead of $Na_2U_2O_7$. Nevertheless the thermochemical cycle used for hydrogen generation can be closed, and chemical compounds used in these processes can also be recycled. So the cycle with $Na_2UO_4$ as its first reaction product has an advantage over the proposed UTC process, attributed to the fast reaction rate and high hydrogen yield in the first reaction step.

접시형 태양열 집광 시스템을 이용한 열화학 사이클의 수소생산 (TWO-STEP THERMOCHEMICAL CYCLES FOR HYDROGEN PRODUCTION WITH DISH TYPE SOLAR THERMAL SYSTEM)

  • 권해성;오상준;서태범
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2011년도 추계학술발표대회 논문집
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    • pp.169-176
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    • 2011
  • The two-step water splitting thermochemical cycle is composed of the T-R (Thermal Reduction)and W-D (Water Decomposition)steps. The mechanism of this cycle is oxidation-reduction, which produces hydrogen. The reaction temperature necessary for this thermochemical cycle can be achieved by a dish-type solar thermal collector (Inha University, Korea). The purpose of this study is to validate a water splitting device in the field. The device is studied and fabricated by Kodama et al (2010, 2011). The validation results show that the foam device, when loaded with $NiFe_2O_4/m-ZrO_2$powder, was successfully achieved hydrogen production with 9 (10 with a Xe-light solar simulator, 2009, Kodama et al.) repeated cycles under field conditions. Two foam device used in this study were tested for validation before an experiment was performed. The lab scale ferrite-conversion rate was in the range of 24~76%. Two foam devices were designed to for structural stability in this study. In the results of the experiments, the hydrogen percentage of the weight of each foam device was 7.194 and $9.954{\mu}mol\;g^{-1}$ onaverage, and the conversion rates 4.49~29.97 and 2.55~58.83%, respectively.

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시베리아산 전나무 바이오매스의 아세톤 용매분해반응 (Acetone Solvolysis of a Siberian Spruce Biomass)

  • 윤성욱
    • 한국수소및신에너지학회논문집
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    • 제20권1호
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    • pp.55-63
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    • 2009
  • In this study, thermochemical degradation by acetone solvolysis reaction of siberian spruce wood was investigated for a temperature range of $200{\sim}400^{\circ}C$. The liquid products by acetone solvolysis from siberian spruce wood produced various kinds of aliphatics, cyclic compounds and aromatics included phenols etc. Combustion heating value of liquid products by acetone solvolysis conversion processes was in the range of $8,010{\sim}8,180cal/g$. The energy yield in acetone solvolysis of siberian spruce wood was as high as 74.2% after 40min of reaction at $400^{\circ}C$. The liquid products from the thermochemical conversion of siberian spruce wood could be used as high-octane-value fuels and fuel additives.

시베리아산 전나무 바이오매스의 열분해-액화반응 (Pyrolysis-Liquefaction of a Siberian Spruce Biomass)

  • 윤성욱
    • 한국수소및신에너지학회논문집
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    • 제19권5호
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    • pp.430-438
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    • 2008
  • Siberian spruce, found in the northern temperature and boreal regions of the earth, is usable biomass as fuels. In this study, parameters of thermochemical degradation by pyrolysis-liquefaction reaction of siberian spruce such as the effect of reaction temperature, reaction time and degradation products and energy yields were investigated. The liquid products from pyrolysis-liquefaction of siberian spruce contained various kinds of cyclicketones, cresols, dimethyl phenols and benzenediols. Combustion heating value of liquid products from pyrolysis-liquefaction conversion processes was in the range of $7,650{\sim}7,800cal/g$. The energy yield in pyrolysis-liquefaction of siberian spruce was as high as 69.5% after 40min of reaction at $400^{\circ}C$. The liquid products from the thermochemical conversion of siberian spruce could be used as high octane value fuels and fuel additives.

석탄순환형 연료전지 모사시스템용 석탄전환율 측정 및 분석법개발에 관한 연구 (Measurement and Analysis of Coal Conversion Efficiency for a Coal Recirculating Fuel Cell Simulator)

  • 이상초;김치환;황문경;김민성;김규보;전충환;송주헌
    • 한국수소및신에너지학회논문집
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    • 제23권5호
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    • pp.503-512
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    • 2012
  • There is a new power generation system such as direct coal fuel cell (DCFC) with a solid oxide electrolyte operated at relatively high temperature. In the system, it is of great importance to feed coal continuously into anodic electrode surface for its better contact, otherwise it would reduce electrochemical conversion of coal. For that purpose, it is required to improve the electrochemical conversion efficiency by using either rigorous mixing condition such as fluidized bed condition or just by recirculating coal particle itself successively into the reaction zone of the system. In this preliminary study, we followed the second approach to investigate how significantly particle recycle would affect the coal conversion efficiency. As a first phase, coal conversion was analyzed and evaluated from the thermochemical reaction of carbon with air under particle recirculating condition. The coal conversion efficiency was obtained from raw data measured by two different techniques. Effects of temperature and fuel properties on the coal conversion are specifically examined from the thermochemical reaction.

고온열 이용 공정의 열역학적 해석 (Thermodynamic Analysis of Thermochemical Process for Water Splitting)

  • 김종원;손현명;이상호;심규성;정광덕
    • 한국수소및신에너지학회논문집
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    • 제13권3호
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    • pp.204-213
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    • 2002
  • In this work, hydrogen production by a 2-step water-spritting thermochemical cycle based on metal oxides redox pairs was investigated on the bases of the thermodynamics and technical feasibility. Also, a 2nd-law analysis performed on the closed cyclic process indicates a maximum exergy conversion efficiency of 7.1% when using a solar cavity-receiver operated at 2300K and air/Fe3O4 molar ratio = 10.

셀룰로오스의 분해특성 및 연료물질 생성[II] - 용해분해 반응 - (Degradation Properties and Production of Fuels from Cellulose - Solvolysis -)

  • 이종집;이병학
    • 한국수소및신에너지학회논문집
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    • 제16권2호
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    • pp.159-169
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    • 2005
  • Cellulose, consisted of 45 wt% in wood, is usable as fuels and heavy oil additives if depolymerized to monomer unit, because the chemical structures are similar to high octane materials found in gasoline. In this study, thermochemical degradation by solvolysis reaction of cellulose such as the effect of reaction temperature, reaction time and type of solvent on conversion yield and degradation products were investigated. It was found that the effectiveness of the solvent on the sovolysis reaction was as follows; acetone>n-butanol>tetralin. When acetone was used as a solvent, the highest cellulose conversion was observed to be 91.8% at 500$^{\circ}C$, 40min. Combustion heating value of liquid products from thermochemical conversion processes was in the range of 7,330${\sim}$7,410cal/g. The energy yield and mass yield in acetone-solvolysis of cellulose was as high as 66.8% and 37.0 g oil/100g raw material after 40min of reaction at 400$^{\circ}C$. Various aliphatic and aromatic compounds were detected in the cellulose solvolysis products. The major components of the solvolysis products, that could be used as fuel, were mesityl oxide, mesitylene, isophorone.