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Chin. J. Process Eng. ›› 2017, Vol. 17 ›› Issue (1): 123-129.DOI: 10.12034/j.issn.1009-606X.216270

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Decomposition Kinetics of Ammonium Bicarbonate and Its Dissolution Property in Weak Alkaline Solution

LIU Wei 1,ZHANG Yan 2,LIU Wen-li 3   

  1. 1. College of chemical and environmental engineering, China university of mining and technology Beijing)
    2. Key Laboratory of Green Process and Engineering, Institute of Process Engineering, CAS
    3. College of Chem. & Environ. Eng., China University of Mining and Technology (Beijing)
  • Received:2016-09-05 Revised:2016-09-30 Online:2017-02-20 Published:2017-02-22
  • Contact: LIU Wen-li lwl@cumtb.edu.cn

碳酸氢铵分解动力学及其在弱碱性条件下的溶解特性

刘伟1,张妍2,刘文礼1   

  1. 1. 中国矿业大学（北京）化学与环境工程学院
    2. 中国科学院过程工程研究所绿色过程与工程实验室
  • 通讯作者: 刘文礼 lwl@cumtb.edu.cn

Abstract: Formaldehyde titration method was used to study the terminal decomposition process of the product of the ammonia method. The concentration variation of main ions was measured when the ammonium bicarbonate solution with initial concentration from 3.0%~7.9% decomposed at 323~363 K. Besides that the determination of the solubility for ammonium bicarbonate in the NH4HCO3?Na2CO3?H2O system from 288 to 313 K was carried by a dynamic method. The results show that the concentration of HCO3? ion falls sharply within the first 30 min and then decreases slowly. The decomposition rate of ammonium bicarbonate solution grows as the temperature rises, at the same temperature the higher the concentration of ammonium bicarbonate solution is, the shorter equilibrium time will be needed. Decomposition process of ammonium bicarbonate solution can be described by the Lageren equation after calculated; It has also been discovered that the solubility of NH4HCO3 increased with the rising of temperature, and increased firstly and then decreased gradually with increasing the concentration of Na2CO3 solution at the same temperature. With a peaked value at Na2CO3 concentration was 0.1 mol/kg when the equilibrium phase changed from NH4HCO3 to NaHCO3 in this aqueous system.

Key words: ammonium bicarbonate, decomposition, kinetics, ammonia method, dissolution property

摘要： 用甲醛滴定法研究了氨法脱碳产物NH4HCO3溶液的受热分解，测定了温度323~363 K、浓度3.0%~7.9%(?)时的NH4HCO3溶液分解过程中主要离子的浓度变化，并用动态法测定了288~313 K时NH4HCO3在Na2CO3?H2O体系中的溶解度. 结果表明，HCO3?浓度在前30 min内先快速下降再平缓下降，NH4HCO3分解速率随温度升高增大. 同一温度下，浓度越高，达到分解平衡所需时间越短. NH4HCO3的分解过程符合Lageren吸附模型；NH4HCO3的溶解度随温度升高而增加，随Na2CO3浓度增加先上升后下降，在0.1 mol/kg时最大，此时平衡固相由NH4HCO3变为NaHCO3.

关键词: 碳酸氢铵, 分解, 动力学, 氨法, 溶解特性

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