无机盐工业

无机盐工业 ›› 2021, Vol. 54 ›› Issue (4): 67-72.doi: 10.11962/1006-4990.2020-0296

• 工业技术 • 上一篇    下一篇

Amomax-10/10H氨合成催化剂升温还原理论与实践

颜鑫1,李练昆2   

  1. 1.湖南化工职业技术学院, 湖南株洲 412000
    2.中国石化巴陵公司煤化工部
  • 收稿日期:2020-10-27 出版日期:2021-04-01 发布日期:2021-04-23
  • 作者简介:颜鑫(1967— ), 男, 工学硕士, 三级教授;E-mail: hnhgyanxin@126.com
  • 基金资助:
    化学工业出版社合作项目(HT-GZYS-2017004)

Theory and practice of heating reduction process of Amomax-10/10H ammonia synthesis catalyst

Xin Yan1,Liankun Li2   

  1. 1. Hunan Institute of Chemical Technology, Zhuzhou 412000, China
    2. Department of Coal Chemical, Sinopec Baling Company
  • Received:2020-10-27 Online:2021-04-01 Published:2021-04-23

摘要:

从Amomax-10/10H催化理论和生产实践两个维度提炼了Amomax-10/10H氨合成催化剂升温还原过程关键技术。理论方面, 从还原反应的特点可以推导出还原过程的基本还原原则, 从铁比[w(Fe 2+)/w(Fe 3+)]和铁氧比[n(Fe)/n(O)]角度来推导出了Amomax-10/10H的近似分子式Fe9O10和Fe9O;从Fe含量高和O含量低的角度, 分析了Amomax-10/10H具有良好的催化活性之理论依据;从纳米级钝化膜处于热力学亚稳定状态, 解释了Amomax-10H具有优异的低温还原性能, 以及解释了高低搭配、先易后难、分层串联还原的理论依据。实践方面:遵循“二高四低”、“阶梯式”升温、“不同时提温提压”的还原操作原则, 这是稳定升温还原操作、防止水气浓度超标、保证催化剂活性的必要举措。

关键词: Amomax-10/10H, 氨合成催化剂, 升温还原

Abstract:

There are dozens of kinds of ammonia synthesis catalyst products, among which the iron-based catalyst is in the absolute position with good activity, good quality, cheap price and long service life.In China, there are more than ten kinds of ironbased catalyst, such as A103, A103H, A106, A109, A110, A201, A203, A207, A207H, A301 and Amomax-10/10H, which areused in ammonia synthesis production successfully.A large number of researches have paid attention to Fe-Co catalysts, rare earth catalysts, ruthenium-based catalysts and Co-Mo bimetallic nitride catalysts. However, in the view of catalyst manufacturing cost and production cost, iron-based catalyst had good success and non-iron based catalyst still only has theoretical significance and it is difficult to replace.No matter which type of iron based ammonia synthesis catalyst, the active ingredients, whether Fe3O4, FeO, Fe1-XO or the pre-reduced catalyst, must be reduced to have catalytic activity.The reduction process is equivalent to the last important step of the catalyst preparation process whose success or failure determines the activity, energy consumption and benefit of the catalyst.Therefore, the reduction process of catalyst is very important, quite“one move accidentally, all lose” meaning.Fe1-XO-based ammonia synthesis catalyst is one of the most active molten iron catalysts in the world and has been widely used.In this paper, the Fe1-XO-based Amomax-10/10H composite catalyst was taken as an example to extract the key technology of the heating reduction process of iron based ammonia synthesis catalyst from both theoretical and practical dimensions.In terms of theory, the basic reduction principle of reduction process could be deduced from the characteristics of reduction reaction and the approximate molecular formulas of Fe9O10 and Fe9O of Amomax-10/10H were accurately deduced from the angle of iron ratio[w(Fe 2+)/w(Fe 3+)] and iron/oxygen ratio[n(Fe)/n(O)].From the point of view of high Fe content and low O content, the theoretical basis of Amomax-10/10H with good catalytic activity was analyzed.The excellent low temperature reduction performance of Amomax-10H was explained from the thermodynamic metastable state of the nanoscale passive film and the theoretical basis of high-low matching, easy first and difficult second, hierarchical series reduction was explained.In practice, the reduction operation principles of “two high and four low”, “step heating” and “different temperature and pressure raising at the same time” were followed, which were the necessary measures to stabilize the temperature rising and reduction operation, prevent the water vapor concentration from exceeding the standard and ensure the catalyst activity.

Key words: Amomax-10/10H, ammonia synthesis catalyst, heating reduction

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