• 论文
主办单位:煤炭科学研究总院有限公司、中国煤炭学会学术期刊工作委员会
工艺条件对费托铁基催化剂气固流化特性的影响
  • Title

    Effect of process conditions on gas-solid fluidization behaviors of iron- based Fischer-Tropsch catalyst

  • 作者

    佟瑞利杨卓鲁波娜冯留海杜冰赵用明卜亿峰门卓武

  • Author

    TONG Ruili1 ,YANG Zhuo2,3 ,LU Bona2,3 ,FENG Liuhai1 ,DU Bing1 ,ZHAO Yongming1 ,BU Yifeng1 ,MEN Zhuowu1

  • 单位

    北京低碳清洁能源研究院中国科学院过程工程研究所多相复杂系统国家重点实验室中国科学院大学化工学院

  • Organization
    1. National Institute of Clean-and-Low-Carbon Energy,Beijing  102211,China; 2. State Key Laboratory of Multiphase Complex Systems,Institute of Process Engineering,Chinese Academy of Sciences,Beijing  100190,China; 3. School of Chemical Engineering,University of Chinese Academy of Sciences,Beijing 100049,China
  • 摘要

    传统上浆态床费托合成铁基催化剂主要采用浆态床反应器进行还原,之后转移至费托合成反应器中进行反应。随着费托合成反应器规模的扩大,配套的浆态床还原技术显现出了生产能力小,还原周期长等不足。通过对费托合成铁基催化剂气固流化特性进行研究,开发产能大、还原周期短的气固流化床还原技术能够显著提高费托合成装置的经济效益。在分析了费托铁基催化剂物性参数的基础上,利用氢气和氮气的混合气模拟还原合成气,在能够升温加压的不锈钢气固流化床反应器内,研究了工艺条件对催化剂气固流化特性的影响,包括温度、压力条件对床层压差脉动幅值的影响,温度、表观气速对反应器床层内气固分布的影响,并结合数值模拟揭示了加压条件下表观气速和温度条件对反应器床层轴向和径向的颗粒体积分数分布、径向颗粒速度分布的影响规律,获得了加压条件下床层从鼓泡流化态到湍动流化态的转变速度并与常压结果进行了对比。实验结果表明,压力增加能够降低床层压差脉动幅值;床层气固分布变化规律及关联计算结果表明在3.0 MPa条件下床层由鼓泡流化态转变为湍动流化态的气速为0.26 m/s。床层不同高度的径向模拟结果表明,在不同表观气速下,反应器内颗粒体积分数都沿径向呈中心稀、边壁浓的“环-核结构”,颗粒速度沿径向呈中心上行、边壁下行的流动趋势;温度升高会造成床层压差脉动幅值减小,但对颗粒体积分数和颗粒速度分布的影响并不显著。在气固流化床的工业运转中适当加大操作压力,利于湍动流化态的形成及流化质量的改善。


  • Abstract

    Traditionally,the iron-based catalysts for Fischer-Tropsch ( F-T) synthesis are reduced in an individual slurry bed reactor before being transferred to the main slurry bed F-T reactor. With the scale-up of F-T reactor,the matching slurry bed reduction technology exhibits the drawbacks of low production capacity and long reduction period.Through the study on the gas-solid fluidization characteristics of iron-based catalysts,the development of gas-solid flu- idized bed technology with high production capacity and low reduction period can significantly improve the economic profit of F-T synthesis plants. Based on the analysis of the physical properties of iron-based catalyst,the influence of process parameters on the fluidization characteristics are investigated in a high-temperature and pressurized stainless- steel gas-solid fluidized bed reactor using the mixture of H2 and N2 as simulated syngas. Specifically,the effects of tem- perature and pressure on the fluctuation of bed pressure drop as well as the impacts of temperature and superficial ve- locity on the gas-solid distribution in the reactor bed are examined,which is combined with the numerical simulation that reveals the influence pattern of superficial velocity and temperature on the axial / radial distribution of solid phase and axial distribution of particle velocity in reactor bed under pressurized condition. The transition velocity of the bed from bubbling state to turbulent state under elevated pressure is obtained and compared with that under atmospheric pressure. The experimental results indicate that the increase in pressure can lower the fluctuation of bed pressure drop. In addition,the bed would start the transition from bubbling state to turbulent state at 0. 26 m / s superficial velocity un- der 3. 0 MPa. The simulation results show that along radial direction,the particle concentration distribution generally presents a “core-annular structure” at different bed heights,while the particle velocity distribution displays a fast up- ward flow at the core area of the bed and a relatively slow downward flow near the wall. Moreover,the increase of tem- perature will also decrease the pressure drop fluctuation,while its effect on particle concentration and particle velocity distribution is insignificant. During the industrial operation,raising the pressure of the gas-solid fluidized bed properly may facilitate the formation of turbulent fluidization and improve the fluidization quality.

  • 关键词

    费托合成铁基催化剂流化床流化特性

  • KeyWords

    Fischer-Tropsch synthesis;iron catalyst;gas-solid fluidized bed;flow behavior

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主办单位:煤炭科学研究总院有限公司 中国煤炭学会学术期刊工作委员会

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