添加剂条件下的甘氨酸结晶过程研究及分子模拟

发布时间：2018-04-18 17:15

本文选题：甘氨酸 + 结晶热力学　；参考：《河北科技大学》2017年硕士论文

【摘要】：作为重要的精细化工中间体,甘氨酸广泛地应用于农药、医药、食品、饲料、光电材料及日用化工等领域。目前,国内生产的甘氨酸产品存在α、γ-晶型混晶、晶习差、粒度分布不均匀及长期储存易结块等问题,严重影响甘氨酸的生产、销售和使用。本论文以此为研究背景,对甘氨酸结晶过程进行了系统研究。添加剂作用下甘氨酸结晶热力学研究。采用激光动态法测定了不同种类添加剂作用下甘氨酸在常压下于293.15-343.15 K温度范围内在水中的溶解度,考察了添加剂种类、添加剂添加量及温度对甘氨酸溶解行为的影响,使用Apelblat经验方程、NRTL方程及λh方程对测定的溶解度数据进行了非线性回归拟合,获得了相关模型参数,建立了不同添加剂条件下的甘氨酸在水中溶解行为的数学模型。对甘氨酸在溶解过程中的热力学性质进行了系统分析,计算得到了甘氨酸在水中溶解过程的标准摩尔焓变、标准摩尔熵变、标准摩尔吉布斯自由能变、焓熵相对贡献、焓-熵补偿、剩余焓,为结晶工艺及动力学的研究提供了基础数据和理论支撑。添加剂作用下甘氨酸在水中的结晶介稳性质研究。本论文系统测定了不同添加剂条件下甘氨酸在水溶液中的超溶解度,获得了溶液结晶介稳区,主要考察添加剂种类、添加剂添加量及温度对甘氨酸介稳区宽度的影响。利用EasyMax装置测定了添加剂种类及添加量、降温速率、搅拌速率对甘氨酸在水溶液中冷却结晶出晶点温度的调控,明确了调控规律。添加剂作用下甘氨酸在水中结晶工艺研究。采用单因素控制法系统研究了不同种类添加剂对甘氨酸结晶过程的影响,以甘氨酸晶体产品的晶型、晶习及粒度分布为研究目标,分析并明确了添加剂对甘氨酸结晶产品质量的影响和调控规律。甘氨酸晶体形态学研究。以添加剂条件下甘氨酸在水溶液中获得的冷却结晶产品为研究对象,应用Materials Studio分子模拟软件对不同晶型的甘氨酸X-射线粉末衍射数据指标化得到相应晶胞参数,进而确定了两种不同晶型甘氨酸的微观结构。利用BFDH模型预测了甘氨酸的理论晶习。
[Abstract]:As an important intermediate of fine chemical industry, glycine is widely used in pesticide, medicine, food, feed, optoelectronic materials and daily chemical industry.At present, there are some problems in domestic glycine products, such as 伪, 纬 -crystal mixed crystal, poor crystal habit, uneven grain size distribution and easy caking in long-term storage, which seriously affect the production, sale and use of glycine.Based on this background, the crystallization process of glycine was studied systematically.Thermodynamics of Glycine Crystallization under the Action of Additives.The solubility of glycine in water under atmospheric pressure at 293.15-343.15 K was determined by laser dynamic method. The effects of additives, additive amount and temperature on the solubility of glycine were investigated.The Apelblat empirical equation and 位 h equation are used to simulate the solubility data, and the related model parameters are obtained. The mathematical model of glycine dissolution in water under different additive conditions is established.The thermodynamic properties of glycine in the dissolution process were systematically analyzed. The standard molar enthalpy, standard molar entropy, standard Gibbs free energy and relative contribution of enthalpy entropy of glycine dissolved in water were calculated.Enthalpy-entropy compensation and residual enthalpy provide basic data and theoretical support for the study of crystallization process and kinetics.Study on the crystal stability of glycine in water under the action of additive.In this paper, the supersolubility of glycine in aqueous solution was systematically determined under different additive conditions, and the crystal metastable region of the solution was obtained. The effects of additives, additive amount and temperature on the width of the metastable zone of glycine were investigated.The kinds of additives, the amount of additives, the cooling rate and the stirring rate of glycine were determined by EasyMax device to control the crystallization point temperature of glycine in aqueous solution.Study on the crystallization process of glycine in water under the action of additive.The effects of different additives on the crystallization process of glycine were systematically studied by single factor control method. The crystal form, crystal habit and particle size distribution of glycine crystal products were studied.The effect of additives on the quality and regulation of glycine crystal products was analyzed and clarified.Morphology of glycine crystals.The cooling crystallization products obtained from glycine in aqueous solution under additive conditions were studied. The corresponding unit cell parameters were obtained by using Materials Studio molecular simulation software to index the X-ray powder diffraction data of glycine in different crystal forms.The microstructures of two different crystal forms of glycine were determined.The theoretical habit of glycine was predicted by BFDH model.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O629.71

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