丙烯酰胺的结晶动力学

采用MSMPR连续结晶器研究了丙烯酰胺的成核 -生长动力学。实验结果表明 ,丙烯酰胺的晶体生长基本符合生长速率与粒度无关的ΔL定律。在小于 1 0 0 μm的晶体粒度范围内 ,存在大量的细小晶粒 ,分析了产生这种现象的 4种可能原因。得到结晶温度分别为 1 0、1 5、2 0℃时 ,丙烯酰胺的成核 -生长动力学模型分别为 :n0 =1 2 6× 1 0 - 5G3 6 6 、n0 =3 92× 1 0 - 5G2 92 、n0 =7 65× 1 0 - 5G3 31 。在 1 0～ 2 0℃内 ,丙烯酰胺的成核 -生长动力学级数为 4 30。动力学级数对温度敏感性较小 ,不能通过调节晶浆密度来控制晶体产品的主粒度。进行了丙烯酰胺结晶的应用研究 ,完成了连续三步式结晶新工艺的概念设计。

Crystallization Kinetics of Acrylamide

Kernel formation and growth kinetics of acrylamide crystals in continuous MSMPR crystallizer was studied.The results show that the growth of crystals accords with Δ L law,that the growth of crystal is independent of the crystal size.The cause of appearing many little particles in the range of 100 μm was concluded in four items.The kinetic models of acrylamide crystallization at 10 ℃,15 ℃ and 20 ℃ were obtained.The kinetic coefficient of acrylamide crystallization is 4 30,and is not sensitive to temperature,thus it is not possible to control the main crystal size by means of adjusting the concentration of suspension.The application study of crystallization was included in the last part of this paper.A new process of continuous three step crystallization was designed.