• Title/Summary/Keyword: Co-pyrolysis

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Radiation Heat Flux and Combustion Characteristics of Inverse Diffusion Flame Burner Using Synthesis Gas, Part 1 : Air-Fuel Combustion (합성가스를 이용한 역확산버너의 연소 및 복사열전달 특성, Part 1 : 공기-연료 연소)

  • Lee, Pil-Hyong;Park, Chang-Soo;Lee, Jae-Young;Park, Bong-Il;Hwang, Sang-Soon;Lee, Sung-Ho;Anh, Yong-Soo
    • Journal of the Korean Society of Combustion
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    • v.14 no.4
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    • pp.33-40
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    • 2009
  • Waste Thermal Pyrolysis Melting process was proposed and has been studied in order to prevent air pollution by dioxin and fly ash generated from combustion process for disposal of waste. In this study, applicability as the fuel of diffusion burner of synthesis gas formed from Waste Thermal Pyrolysis process was addressed. Results showed that there is no big difference in the flame shape between MNDF and SNDF, and lift off was detected in MIDF but flame is more stable in SIDF which contains hydrogen with high combustion velocity as flow rate in first nozzle is increased. And radiation heat flux in inverse diffusion flame of synthesis gas was found to be more by 1.5 times than that in inverse diffusion flame of methane because of higher mole fraction of $CO_2$ with high emissivity in product gas.

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Application of Spray Pyrolysis Process for Production of Ultra Pure and Fine Powder. (고순도 초미립 분체제조를 위한 분무열분해법의 응용)

  • Yu, Jae-Keun;Park, Hee-Beom;Park, Joo-Ill;Han, Jung-Soo;Han, Jin-A;Nam, Yung-Hyeon
    • Proceedings of the KAIS Fall Conference
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    • 2000.10a
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    • pp.39-41
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    • 2000
  • Newly modified spray Pyrolysis system was developed to Produce ultra Pure and fine Powder by spray Pyrolysis Process. In this system, raw material solution was effectively atomized and sprayed into the reaction furnace. Also, thermal decomposition process fully completed in the three zone reaction furnace, and produced powder was effectively collected. A technology to reduce impurities in complex acid solution below 20ppm was also developed. The characteristics of produced powder were studied by changing the reaction conditions such as reaction temperature, the injection velocity of the solution and air, nozzle tip size and concentration of solution. The morphology of powder had spherical shape under the most experimental conditions, and the composition and the particle size distribution were almost uniform. Under the most experimental conditions average particle size of most produced powder was below 100nm.

Up-conversion Luminescence Characterization of CeO2:Ho3+/Yb3+ Particles Prepared by Spray Pyrolysis

  • Jung, Kyeong Youl;Min, Byeong Ho;Kim, Dae Sung;Choi, Byung-Ki
    • Current Optics and Photonics
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    • v.3 no.3
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    • pp.248-255
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    • 2019
  • Spherical $CeO_2:Ho^{3+}/Yb^{3+}$ particles were synthesized using spray pyrolysis, and the upconversion (UC) properties were investigated with changing the preparation conditions and the infrared pumping power. The resulting particles had a size of about $1{\mu}m$ and hollow structure. The prepared $CeO_2:Ho^{3+}/Yb^{3+}$ particles exhibited intense green emission due to the $^5F_4/^5S_2{\rightarrow}^5I_8$ transition of $Ho^{3+}$ and showed weak red or near-IR peaks. In terms of achieving the highest UC emission, the optimal concentrations of $Ho^{3+}$ and $Yb^{3+}$ were 0.3% and 2.0%, respectively. The UC emission intensity of prepared $CeO_2:Ho^{3+}/Yb^{3+}$ particles had a linear relationship with crystallite size and concentration quenching was caused by dipole-dipole interaction between the same ions. Based on the dependency of UC emission on the pumping power, the observed green upconversion was achieved through a typical two-photon process and concluded that the main energy transfer from $Yb^{3+}$ to $Ho^{3+}$ was involved in the ground-state adsorption (GSA) process.

Preparation of GdBCO Thin Film by Ex-situ Process using Nitrate Precursors (질산염 전구체 원료로 Ex-situ 공정에 의한 GdBCO 박막 제조)

  • Kim, Byeong-Joo;Lee, Chul-Sun;Lee, Jong-Beom;Lee, Jae-Hun;Moon, Seung-Hyun;Lee, Hee-Gyoun;Hong, Gye-Won
    • Progress in Superconductivity
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    • v.13 no.2
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    • pp.127-132
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    • 2011
  • Many research groups have been manufacturing coated conductor by various processes such as PLD, MOD, and MOCVD, but the methods with production cost suitable for wide and massive application of coated conductor did not develop yet. Spray pyrolysis method adopting ultrasonic atomization was tried as one of the possible option. GdBCO precursor films have been deposited on IBAD substrate by spray pyrolysis method at low temperature and converted to GdBCO by post heat treatment. Ultrasonic atomization was used to generate fine droplets from precursor solution of Gd, Ba, and Cu nitrate dissolved in water. Primary GdBCO films were deposited at $500^{\circ}C$ and oxygen partial pressure of 1 torr. After that, the films were converted at various temperatures and low oxygen partial pressures. C-Axis oriented films were obtained IBAD substrates at conversion temperature of around $870^{\circ}C$ and oxygen partial pressures of 500 mtorr ~ 1 torr in a vacuum. Thick c-axis epitaxial film with the thickness of 0.4 ~ 0.5 ${\mu}m$ was obtained on IBAD substrate. C-axis epitaxial GdBCO films were successfully prepared by ex-situ methods using nitrate precursors on IBAD metal substrate. Converted GdBCO films have very dense microstructures with good grain connectivity. EDS composition analysis of the film showed a number of Cu-rich phase in surface. The precursor solution having high copper concent with the composition of Gd : Ba : Cu = 1 : 2 : 4 showed the better grain connectivity and electrical conductivity.

Photoluminescence Enhancement of Y2O3:Eu3+ Red Phosphor Prepared by Spray Pyrolysis using Aliovalent Cation Substitution and Organic Additives (이가 양이온 금속 친환 및 유기 첨가제를 이용하여 분무열분해법으로 제조된 Y2O3:Eu3+ 적색 형광체의 휘도 개선)

  • Min, Byeong Ho;Jung, Kyeong Youl
    • Journal of Powder Materials
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    • v.27 no.2
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    • pp.146-153
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    • 2020
  • The co-doping effect of aliovalent metal ions such as Mg2+, Ca2+, Sr2+, Ba2+, and Zn2+ on the photoluminescence of the Y2O3:Eu3+ red phosphor, prepared by spray pyrolysis, is analyzed. Mg2+ metal doping is found to be helpful for enhancing the luminescence of Y2O3:Eu3+. When comparing the luminescence intensity at the optimum doping level of each Mg2+ ion, the emission enhancement shows the order of Zn2+ ≈ Ba2+ > Ca2+ > Sr3+ > Mg2+. The highest emission occurs when doping approximately 1.3% Zn2+, which is approximately 127% of the luminescence intensity of pure Y2O3:Eu3+. The highest emission was about 127% of the luminescence intensity of pure Y2O3:Eu3+ when doping about 1.3% Zn2+. It is determined that the reason (Y, M)2O3:Eu3+ has improved luminescence compared to that of Y2O3:Eu3+ is because the crystallinity of the matrix is improved and the non-luminous defects are reduced, even though local lattice strain is formed by the doping of aliovalent metal. Further improvement of the luminescence is achieved while reducing the particle size by using Li2CO3 as a flux with organic additives.

Effects of Particle Size and Pyrolysis Temperature of Oyster Shell on Change of Coastal Benthic Environment (굴 패각의 입경 및 소성 온도에 따른 연안 오염 저서환경 변화 연구)

  • Jeong, IlWon;Woo, Hee-Eun;Lee, In-Cheol;Yoon, SeokJin;Kim, Kyunghoi
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.26 no.7
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    • pp.873-880
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    • 2020
  • After pre-treatment of oyster shells according to particle size (0 ~ 1, 1 ~ 2, 2 ~ 5 mm) and pyrolysis temperature (400(P400), 500(P500), 600(P600), 800(P800)℃), changes in the properties of sediments mixed with pre-treated oyster shells were investigated. The primary component of the oyster shell was changed from CaCO3 to CaO at temperatures above 700℃. The Ca2+ concentration in P800 was 790 mg/L, which was 2 ~ 3 times higher than those in the control and other experimental samples. Ca2+ elution significantly increased at the pyrolysis temperature over than 600℃. In oyster shells pyrolyzed over 600℃, the pH of the pore water increased by 0.1 ~ 0.5, due the hydrolysis of CaO formed by the pyrolysis of CaCO3. The PO4-P of the overlying and pore water in P600 and P800 were 0.1 ~ 0.2 mg/L lower than those of the control. The increased pH and elution of Ca2+ from oyster shells should suppress the upwelling of PO4-P from the sediment. Based on the above results, it was confirmed that the pyrolysis temperature of oyster shells influenced NH3-N and PO4-P concentrations in the sediment; however, the particle size of oyster shells had little effect. The results of this study can be used as a foundation for research on the use of pyrolyzed oyster shells to improve low-contamination coastal benthic environments.

A Study on Characteristics of Wood Pellet Gasification in Two Stage Gasifier (Two Stage Gasifier에서의 우드펠릿 가스화 특성 연구)

  • Lee, Moon-Won;Choi, Sun-Yong;Kim, Lae-Hyun
    • Journal of Energy Engineering
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    • v.19 no.4
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    • pp.240-245
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    • 2010
  • In this study, characteristics of wood pellet gasification was studied using a Two Stage Gasifier which is consisted of pyrolysis reactor and ultra high temperature reformer. The average yields of $H_2$, $CH_4$, CO, $CO_2$ were 16.7, 11.3, 37.2, 26.6 L/mim, conversion rate from biomass to gas was 65% in pyrolysis reactor and gas yields in reformer were 55.4, 0.8, 120.8, 56.8 L/mim, respectively. The hydrogen flow rate from reformer is obtained 360.1 L/hr. The most of $CH_4$ was decomposed from 12.3 to 0.3 vol.% while $H_2$ is from 18.2 to 23.7 vol.% in reformer by methane dry reforming, Boudouard reaction, oxidation and/or steam reforming. The amount of $H_2O$ generated by hydration reaction from reformer was 1111.8 g, its accelerated conversion of $CH_4$ to other products. The conversion rate from $CH_4$ to other Compounds was 97.2%. Cold gas efficiency was 53.2%.

Pyrolysis and Breaking Characteristics of Waste Wood for Wood-wool Board (Wood-wool board로 활용(活用)을 위한 폐목재(廢木材)의 열분해(熱分解) 및 파쇄특성(破碎特性))

  • Park, Sang-Min;Kim, Jae-Woo;Sim, Ki-Sup;Park, Sang-Sook
    • Resources Recycling
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    • v.19 no.2
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    • pp.19-27
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    • 2010
  • The purpose of this research was to see thermal and breaking type characteristics of waste wood for construction materials using high temperature and pressure equipment. In TG/DTA graph weight of waste wood was steeply decreased at $250^{\circ}C$, it has to be treated below $250^{\circ}C$ for construction materials. In popping test the needle-leaved tree was more broken in texture than the broad-leaved tree, especially, Chamaecyparis obtusa(W-7) was the best. The optimum result was obtained at temp. $200^{\circ}C$, pressure 3MPa among the experimental condition.

Characteristics of pyrolysis gas production in charcoal production process of lignocelluloisic biomass (목질계 바이오매스 숯 생산 공정에서 발생하는 열분해가스 생산 특성)

  • Park, Soo-Nam;Ku, Jae-Hoi;Lim, Yong-Taek;Xu, Lihua;Seo, Yong-Kyo;Lee, Il-Kyu;Ha, Hu-Chan
    • 한국신재생에너지학회:학술대회논문집
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    • 2009.06a
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    • pp.443-446
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    • 2009
  • 바이오매스 에너지라 함은 생물체를 구성하는 유기물을 이용하는 에너지이다. 바이오매스는 에너지 위기 및 $CO_2$에 의한 지구온난화 및 화석자원의 고갈이 진행되면서, 화석연료와 달리 재생이 가능하고 지속 가능한 자원으로 각광을 받고 있다. 그 중에서도 목질계 바이오매스는 다른 신재생에너지원에 비해 국내 잠재량이 가장 풍부한 에너지원 중의 하나이다. 바이오매스 에너지 기술로는 직접연소, 열화학적 변환, 생화학적 변환의 기술이 있다. 본 연구에서는 목재를 원료로 한 부분산화 조건의 숯 생산 공정에서 목재의 열분해 가스 생산특성을 고찰하였다. 열분해가스 중에 응축된 목초액의 pH는 3.58~3.92 정도로 분석 되었고, 산도는 시간이 경과 할수록 2.74에서 4.44%로 농도가 증가 되었다. 숯 생산 공정에서의 목재의 열분해는 초기부터 48시간까지는 열분해가스의 조성의 변화가 거의 없었고, 48시간 경과 후에는 열분해가스 중에 가연성가스인 $H_2$, CO, $CH_4$가 약 5%정도 배출되는 것을 알 수 있었다.

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