【作者】 强黎明；

【导师】 蒋登高； 周彩荣；

【作者基本信息】 郑州大学 ， 化学工艺， 2004， 硕士

【摘要】 本文针对以环己烯为原料合成反式-1，2-环己二醇绿色工艺路线中目的产品的分离问题，以及与之相关的物性数据等进行研究，探索出了能耗低、节省原料、操作简便、适宜于工业化生产的分离工艺，为反式-1，2-环己二醇的大规模工业化生产奠定了基础。 本文采用合成法和激光技术测定了反式-1，2-环己二醇在水和乙酸乙酯中及甲酸钠在水中的溶解度和超溶解度数据，得到了反式-1，2-环己二醇在水中的介稳区宽度与温度和搅拌速度的关系曲线，以及反式-1，2-环己二醇在乙酸乙酯中、甲酸钠在水中的介稳区宽度与温度的关系曲线。 实验结果表明，反式-1，2-环己二醇在水中和乙酸乙酯中的溶解度、超溶解度和介稳区宽度AS皆随温度的升高而增加，且反式-1，2-环己二醇在水中的溶解度、超溶解度和介稳区宽度AS远远大于其在乙酸乙酯中的溶解度、超溶解度和介稳区宽度△S；而反式-1，2-环己二醇在水中的溶解度、超溶解度和介稳区宽度△S均随搅拌速度的提高而减小。反式-1，2-环己二醇在水中的介稳区宽度△θ，高速搅拌下为4℃左右，中速搅拌下为了℃左右；在乙酸乙酯中的介稳区宽度△θ为3℃左右。甲酸钠在水中的溶解度、超溶解度和介稳区宽度△S均随温度的升高而呈线性增加，介稳区宽度△θ在4～5℃之间。实验结果为反式-1，2-环己二醇的分离提纯、结晶工艺条件的优化以及结晶动力学、连续分步结晶工艺的进一步研究提供了必要的热力学基础。 应用间歇减压精馏对热敏性、高沸点、高凝固点的有机物—反式-1，2-环己二醇进行分离、提纯，通过采用变压强、变回流比的方法，优化出了最佳的操作工艺条件。同时还对反式-1，2-环己二醇合成工艺中过量甲酸的回收进行了研究，得到了常压间歇精馏浓缩回收甲酸的工艺条件。从萃取液中除去乙酸乙酯的变压强、变回流比间歇精馏的操作条件是：加热电压140V，初期采用常压精馏，全回流开工时间30min；回流比0.3，塔釜温度达到85℃时，停止加热，降温；降温到40℃时，减压蒸馏，真空度0.078—0.080MPa，回流比0.3，直到釜中反式-1，2-环己二醇全部结晶为止。提纯粗品的变压强、变回流比减压间歇精馏的操作条件是：塔顶用温度为96℃左右的热水做冷凝剂；全回流开工时间2h；控制釜温180—185℃，分段恒真空度0.086—0.092MPa；分段恒回流比5→8→12。在此操作条件下所得产品的收率在87％以上，产品纯度可达98％以上，色泽较白。产品的红外光谱图与美国进口产品吻合较好，且熔点与文献值一致。 通过甲酸回收实验证明，用88％的甲酸进行合成反应后回收的甲酸，不必经过浓缩，可直接用于合成反应，不影响反式-1，2-环己二醇的收率；用循环回收的甲酸进行合成反应，需经过精馏浓缩。精馏过程的回流比宜选择为6，全回流时间宜选择为0.5h。精馏后浓度可达75％以上，回收率在70％以上，且循环回收的甲酸用于合成反应也不影响反郑州大学硕士学位论文式一1，2一环己二醇的收率。更多还原

【Abstract】 In this article the method of separation and purification of trans-1,2-cyclohexanediol and related thermodynamic data are studied based on the green synthesizing technique of trans-1,2-cyclohexanediol from cyclohexene which has been successfully developed in our laboratory. The separation technique was gained, which can save energy and raw materials and is convenient and fitted for industrial production. All these will make base for the industrial production of trans-1,2-cyclohexanediol.The saturate and supersaturate characters of trans-1,2-cyclohexanediol in water, ethyl acetate at different temperature and agitation rates were investigated with synthesis method and using laser technique, as well as those of sodium formate in water at different temperature. The crystallization metastable zone width of trans-1,2-cyclohexanediol and sodium formate was also obtained.The test results show that the solubility, supersolubility and crystallization metastable zone width (AS) of trans-1,2-cyclohexanediol in both water and ethyl acetate all increase with temperature growth, and those properties of trans-1,2-cyclohexanediol in water are larger more than those in ethyl acetate. While, the super-solubility and crystallization metastable zone width (AS) of trans-1,2-cyclohexanediol in water decrease with the raising of agitation rate. The crystallization metastable zone width ( ) of trans-1,2-cyclohexanediol in water is about 4C under high agitation rate, and about 7 C under middle agitation rate. The crystallization metastable zone width ( ) of trans-1,2-cyclohexanediol in ethyl acetate is about 3 C. The solubility, super-solubility and crystallization metastable zone width (AS) of sodium formate increase with temperature growth and the crystallization metastable zone width ( ) is between 4 C and 5C. These results offer necessary thermal data for the separation and purification of trans-1,2-cyclohexanediol, the optimization of crystallization process of trans-1,2-cyclohexanediol and the study of crystallization kinetics and batch crystallization of trans-1,2-cyclohexanediol.Trans-1,2-cyclohexanediol which has heat sensitivity, high boiling point and high coagulating point was separated and purified with batch distillation under vacuum. The distillation was operated by changing pressure and reflux ratio strategy. The optimal operating condition was acquired. Meanwhile, the recycle of the excessive formic acid in the synthesis of trans-1,2-cyclohexanediol was studied and the recycle technique of formic acid by batch distillation under common pressure was got. The operating condition with changing pressure and changing reflux ratio of batch distillation which eliminate ethyl acetate fromextracting liquid is that the operation pressure is latm at the beginning and heating voltage 140V, the beginning time of overall reflux 30 min, reflux ratio 0.3. Heating is stopped and the bottom temperature is lowered when it rises to 85 C. Vacuum distillation is employed after the bottom temperature comes down to 40 C. The vacuum distillation isn’t stopped under the condition that vacuum is 0.078 ~ 0.080 MPa and reflux ratio 0.3, until all trans- 1,2-cyclohexanediol crystallizes. The operating condition with changing pressure and changing reflux ratio of batch distillation under vacuum which purifies raw trans-1,2-cyclohexanediol is that the beginning time of overall reflux is 2h and the bottom temperature 180~185C, the changing vacuum 0.086~0.092 MPa, the changing reflux ratio 5-8- 12. The production ratio of trans-1,2-cyclohexanediol is over 87% and the product purity is beyond 98% under the above operation condition. The product’s color gets much more whiter than the raw’s. The IR graph of the product is in agreement with that of sample imported from America, as well as it’s melting point.By the recycle test, we have proved that the formic acid recycled firstly can be used for synthesis cyclically without concentration and has no effect on production ratio of trans-1,2-cyclohexanediol. The formic acid recycled cyclically is con更多还原