批次結晶程序之動力模型彙整及分析

Abstract

本篇研究匯集了七個批次結晶程序之動力模型。電腦最適化結果顯示，後期成長策略有幫助於減少新成核晶體重量。然而，初期成長策略僅當成核級數小於長晶級數時才有減少新晶體重量的效果。此外，我們透過電腦製作晶種分析圖，決定出不同批次反應時間下之臨界晶種負載率，並將其與Kubota所提出之方程式做比較。由比較結果可知Kubota方程式可簡單地決定出臨界晶種負載率，且大致上適用於不同結晶系統。批次總反應時間影響臨界晶種負載率的分析指出，在成核級數大於長晶級數的條件下，總反應時間的增加可以讓晶種負載使用量下降並仍然達到減少新晶體重量的效果。當成核級數大於長晶級數時，增加總反應時間便無法在少量晶種負載下達到減少新晶體重量的效果，此時唯一的好處只在於能獲得較大晶體。

Seven published crystallization kinetics from batch crystallizer is compiled, and the simulation and optimization of crystallization process are also provided. The results suggest that a late growth policy would be appropriate to minimize the final nucleated crystal mass. However, an early growth policy seems to be only efficient to minimize the final nucleated crystal mass when nucleation order is smaller than growth order. The critical seed loading ratio is determined for the seven systems with different batch times and compared with Kubota’s equation [JCEJ. 2002; 35(7): 670−676]. It shows that Kubota’s equation is simple and can be easily applied to different crystallization processes. The results of the effect of total batch time on critical seed loading ratio indicate increasing batch time can reduce nucleated mass with low seed loading as nucleation order is larger than growth order. When nucleation order is smaller than growth order, increasing batch time can only increase the final product size and is improper of reducing nucleated mass with low seed loading.