微反应器内自热结晶法制备磷酸二氢铵

Preparation of Monoammonium Phosphate by Autothermal Crystallization in a Microreactor

为制备高纯固体磷酸二氢铵（MAP）并降低过程能耗,本工作提出一种基于微反应器的新工艺——自热结晶法。通过对该过程中放热、汽化、通道内结晶等现象的研究,更清楚地认识了微反应器内自热结晶法制备MAP的过程规律,为微反应器的设计及最佳工艺的选择提供了基础参数与理论支持。在酸碱物质的量比为1：1,MAP预设质量浓度为33.2%~55.0%时,获得了约40%的结晶收率,且所得样品晶粒小、纯度较高。实验证明,该方法在有效降低能耗的同时保证了较高的产率,具有良好的工业应用价值。

In this paper, a new process, namely autothermal crystallization, was proposed to prepare high purity solid monoammonium phosphate（MAP） in a microreactor with low energy consumption. The principle of the process was understood more thoroughly by the study of heat release, water vaporization and the inner crystallization phenomena in the process of preparation of MAP from autothermal crystallization in the microreactor, which provided fundamental data and theoretical support for microreactor design and parameter optimization. At the molar ratio of acid to base 1：1 and the concentration of MAP（cMAP） of 33.2%-55.0%（w）, a high crystallization yield of 40% was achieved, and the as-prepared MAP possessed small crystallite size and high purity. The experiments showed that this method can effectively reduce the energy consumption while maintaining a high yield, indicating that the process had great potential in the industrial production of solid MAP.