• Title, Summary, Keyword: reforming

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The Effect of Operating Conditions on the Heat-flow Characteristics and Reforming Efficiency of Steam Reformer with Combustor (연소기가 장착된 수증기 개질기에서 운전조건이 열유동 특성 및 개질효율에 미치는 영향)

  • Kim, Ji-Seok;Lee, Jae-Seong;Kim, Ho-Young
    • Journal of the Korean Society of Combustion
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    • v.16 no.1
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    • pp.36-45
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    • 2011
  • The heat-flow characteristics and reforming efficiency of steam reformer with combustor are numerically investigated at various operating conditions. SCR(Steam to Carbon Ratio) and GHSV(Gas Hourly Space Velocity) are adopted as important operating conditions. User-Defined-Function(UDF) was used to simultaneously calculate reforming and combustion reaction. Numerical results show that hot burned gas rise by a buoyant force and heat exchange between reforming reactors and cocurrent flow occurs in the combustion region. The results also indicate that an increase of SCR leads to decrease the mole fraction of hydrogen at the reactor outlet. As GHSV increases, conversion rate decreases.

Numerical Study on operating conditions of Autothermal Reformer using natural gas (천연가스를 이용한 자열개질기의 운영조건에 대한 수치해석 연구)

  • Kim, Jinwook;Kim, Sangwoo;Park, Dalyung;Jeon, Sanghee;Lee, Dohyung
    • 한국신재생에너지학회:학술대회논문집
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    • pp.91.1-91.1
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    • 2010
  • The Reforming system is an effective method to generate hydrogen which uses for fuel cell system. The purpose of this study is to present characteristics of an autothermal reformer at various operating conditions and to investigate ideal conditions for reforming efficiency. Dominant chemical reactions are Full Combustion, Steam Reforming reaction, Water-Gas Shift reaction and Direct Steam Reforming reaction. Operating parameters of the autothermal reformer are inlet temperature, Oxygen to Carbon Ratio, Steam to Carbon Ratio and Gas Hourly Space Velocity. Autothermal reformer is filled with catalysis of a packbed-bed type. Using numerical approach, we have investigated on various reaction conditions.

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Carbon Deposition on Nickel Catalyst for Pre-reforming of Propane (니켈 촉매를 이용한 프로판 예개질 반응의 탄소침적에 대한 연구)

  • Kim, Sun-Young;Bae, Joong-Myeon
    • 한국신재생에너지학회:학술대회논문집
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    • pp.487-490
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    • 2008
  • Temperature programmed oxidation (TPO) is used to characterize coke species deposited on commercial nickel catalyst, C11-PR during propane pre-reforming. Propane pre-reforming performed under various condition, S/C from 1.5 to 2.5 and temperature from $350^{\circ}C$ to $450^{\circ}C$. There are three kinds of coke species detected by TPO: (i) reactive coke, (ii) coke deposited on metal site and (iii) coke deposited on acid support. Coke deposited on metal and support are minimized although reactive coke is generated at temperature of $400^{\circ}C$ and S/C of 2.0. Reactive coke is expected to remove easily below temperature of $200^{\circ}C$. Therefore, optimized pre-reforming condition for propane is $400^{\circ}C$ and S/C of 2.0.

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Experimental study on self-sustaied $1kW_e$ liquid fuel reforming operation (자립형 $1kW_e$ 액체 연료 개질기 운전에 관한 연구)

  • Yoon, Sang-Ho;Bae, Gyu-Jong;Bae, Joong-Myeon
    • 한국신재생에너지학회:학술대회논문집
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    • pp.503-506
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    • 2008
  • Liquid hydrocarbon fuels, such as gasoline, kerosene, diesel and JP 8, can be good candidates for SOFC (solid oxide fuel cell) system fuel due to their high hydrogen density. Autothermal reforming (ATR) is suitable for liquid hydrocarbon fuel reforming because oxygen can decompose the aromatics in liquid fuel and steam can suppress the carbon deposition during catalytic reaction. The advantage of ATR is that it has a simple system construction due to exothermicity of ATR reaction. We control the exothermicity of reaction, make the reaction possible design a self-sustaining ATR reactor. A self-sustained 1kW-class kerosene autothermal reformer is introduced in this paper. The 1kW-class kerosene reformer was continuously operated for about 140 hours without degradation of reforming performance.

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Hydrogen Generation Characteristics of SMART Process with Inherent $CO_2/H_2$ Separation (CO$_2/H_2$ 원천분리 SMART 공정의 수소생산특성)

  • Ryu, Ho-Jung
    • 한국신재생에너지학회:학술대회논문집
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    • pp.55-58
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    • 2007
  • To check the feasibility of SMART (Steam Methane Advanced Reforming Technology)system, an experimental investigation was conducted. A fluidized bed reactor of diameter 0.052 m was operated cyclically up to the $10^{th}$ cycle, alternating between reforming and regeneration conditions. FCR-4 catalyst was used as the reforming catalyst and calcined limestone (domestic, from Danyang) was used as the $CO_2$ absorbent. Hydrogen concentration of 98.2% on a dry basis was reached at $650^{\circ}C$ for the first cycle. This value is much higher than $H_2$ concentration of 73.6% in the reformer of conventional SMR (steam methane reforming) system. However, the hydrogen concentration decreased because the $CO_2$ capture capacity decreased as the number of cycles increased.

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On the Implementation of Failure Diagnosis System for Naphtha Reforming Process (나프타 개질공정을 위한 이상 진단시스템의 구현)

  • Cha, Un-Ok
    • Journal of the Korean Society for Quality Management
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    • v.20 no.1
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    • pp.91-100
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    • 1992
  • A diagnosis system for naphtha reforming process has been designed and implemented using expert system building technique. The system is composed of knowledge base, inference engine, user interface, database and database interface. The concept and the method of this system may be applied to development of other systems for the reforming process.

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Studies on the Production of Hydrogen by the Steam Reforming of Glycerol Over NI Based Catalysts (NI계 촉매상에서 글리세롤의 수증기 개질반응(Steam Reforming)에 의한 수소제조 연구)

  • Hur, Eun;Moon, Dong-Ju
    • Transactions of the Korean hydrogen and new energy society
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    • v.21 no.6
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    • pp.493-499
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    • 2010
  • Steam reforming (SR) of glycerol, a main by-product of manufacturing process of bio-diesel, for the production of hydrogen was investigated over the Ni-based catalysts. The Ni-based catalysts were prepared by an impregnation method, and characterized by $N_2$ physisorption, CO chemisorption, XRD and TEM techniques. It was found that the Ni/${\gamma}-Al_2O_3$ catalyst showed higher conversion and catalytic stability for the carbon formation than the other catalysts in the steam reforming of glycerol under the tested conditions. The results suggest that the steam reforming of glycerol over modified Ni/${\gamma}-Al_2O_3$ catalyst minimized carbon formation can be applied in hydrogen station for fuel-cell powered vehicles and fuel processor for stationary and portable fuel cells.

Effect of Carbon Capture Using Pre-combustion Technology on the Performance of Gas Turbine Combined Cycle (연소전 처리를 이용한 탄소포집이 가스터빈 복합화력 플랜트의 성능에 미치는 영향)

  • YOON, SUKYOUNG;AHN, JIHO;CHOI, BYEONGSEON;KIM, TONGSEOP
    • Transactions of the Korean hydrogen and new energy society
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    • v.27 no.5
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    • pp.571-580
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    • 2016
  • In this paper, performance of the gas turbine combined cycle(GTCC) using pre-combustion carbon capture technology was comparatively analysed. Steam reforming and autothermal reforming were used. In the latter, two different methods were adopted to supply oxygen for the reforming process. One is to extract air form gas turbine compressor (air blowing) and the other is to supply oxygen directly from air separation unit ($O_2$ blowing). To separate $CO_2$ from the reformed gas, the chemical absorption system using MEA solution was used. The net cycle efficiency of the system adopting $O_2$ blown autothermal reforming was higher than the other two systems. The system using air blown autothermal reforming exhibited the largest net cycle power output. In addition to the performance analysis, the influence of fuel reforming and carbon capture on the operating condition of the gas turbine and the necessity of turbine re-design were investigated.

Study on Internal Reforming Characteristic of 1 kW Solid Oxide Fuel Cell Stack (1 kW 고체산화물 연료전지 스택의 내부개질 특성 연구)

  • CHOI, YOUNGJAE;AHN, JINSOO;LEE, INSUNG;BAE, HONGYOUL;MOON, JIWOONG;LEE, JONGGYU
    • Transactions of the Korean hydrogen and new energy society
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    • v.28 no.4
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    • pp.377-383
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    • 2017
  • This paper presents the performance characteristics of a 1 kW solid oxide fuel cell (SOFC) stack under various internal reforming and fuel utilization conditions. The Research Institute of Industrial Science & Technology (RIST) developed the 9-cell stack using a $20{\times}20cm^2$ anode supported planar cell with an active area of $324cm^2$. In this work, current-voltage characteristic test, fuel utilization test, continuous operation, and internal reforming test were carried out sequentially for 765 hours at a furnace temperature of $700^{\circ}C$. The influence of fuel utilization and internal reforming on the stack performance was analyzed. When the 1 kW stack was tested at a current of 145.8 A with a corresponding fuel utilization of 50-70% (internal reforming of 50%) and air utilization of 27%, the stack power was approximately 1.062-1.079 kW. Under continuous operation conditions, performance degradation rate was 2.16%/kh for 664 hours. The internal reforming characteristics of the stack were measured at a current of 145.8. A with a corresponding fuel utilization of 60-75%(internal reforming of 50-80%) and air utilization of 27%. As fuel utilization and internal reforming ratio increased, the stack power was decreased. The stack power change due to the internal reforming ratio difference was decreased with increasing fuel utilization.

Research of High Efficiency Integrated Reforming System Using Separated Reforming System (분리형 개질기를 이용한 고효율 일체형 개질기 개발에 관한 연구)

  • PARK, SANG-HYOUN;KIM, CHUL-MIN;SON, SUNG-HYO;JANG, SE-JIN;KIM, JAE-DONG;BANG, WAN-KEUN;LEE, SANG-YONG
    • Transactions of the Korean hydrogen and new energy society
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    • v.29 no.1
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    • pp.11-18
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    • 2018
  • A high efficiency integrated reforming system for improving the efficiency of the 5 kW PEMFC system used as the back up power of building was studied. The separated reforming system consisted of three parts - A steam reformer with two stage concentric circular shape, a heat exchanger type steam generator and a CO shift reactor. Temperature and steam carbon ratio (SCR) were control variables during operation. The operating conditions were optimized based on the thermal efficiency of the steam reformer as reformate gas composition changes at different temperature. In experiments, water was fully vaporized in the steam generator up to SCR 3.5 and the maximum thermal efficiency was achieved at the operating temperature around $700^{\circ}C$ in the steam reforming reactor. With the results of the separated reforming system research, we improved the shape of high efficiency integrated reformer. The performance evaluation of the integrated reformer was based on optimized operating conditions in SCR 3.5. As a result, the developed integrated reforming system maintained an efficiency of 76% and constant performance over 3,000 hours.