How To Crystallize Anhydrous Racemic Tartaric Acid from an Ethanol鈥揥ater Solution

详细信息    查看全文

• 作者：Xiaofang Wang ; Leping Dang ; Simon Black ; Xiangyang Zhang ; Hongyuan Wei
• 刊名：Industrial & Engineering Chemistry Research
• 出版年：2012
• 出版时间：February 15, 2012
• 年：2012
• 卷：51
• 期：6
• 页码：2789-2796
• 全文大小：422K
• 年卷期：v.51,no.6(February 15, 2012)
• ISSN：1520-5045

文摘

Racemic tartaric acid (TA) exists in the solid state as an anhydrate and a monohydrate. In this paper, a method to obtain the anhydrate at lower temperature by adjusting the water activity, a_w, through introduction of ethanol is proposed. The influence of a_w on the phase conversion temperature of TA was investigated by the determination of the ternary phase diagrams for the system of water鈥揺thanol鈥揟A at varying temperatures. The result shows that the anhydrous TA can be obtained at ambient temperature by lowering the water activity and that the conversion rate from monohydrate to anhydrate appears to increase with decreasing water activity. The result can be extended to the application of other anhydrate and hydrate systems. Meanwhile, the process of anhydrous TA crystal formation from ethanol鈥搘ater solution was investigated by using microscopy and HPLC.