【作者】 钟琮；

【导师】 黄梅；

【作者基本信息】 浙江大学 ， 应用化学， 2008， 硕士

【摘要】 模拟移动床色谱技术（SMB）作为一种先进分离技术在精细化工、制药和生化领域取得了巨大发展,目前正处于从尖端技术向成熟工艺流程转型阶段,并有朝着分离-反应一体化方向发展的趋势。胆固醇是脊椎动物细胞的重要组成部分,具有形成胆酸、构成细胞膜、合成激素等重要生理功能,广泛应用于化妆品、乳化剂、医药等领域。24-去氢胆固醇是胆固醇生物合成途径中的直接前体,与胆固醇相比因为支链带双键,所以在许多具有重要生理活性的甾醇合成中更有优势。本文是对羊毛酯中胆固醇和24-去氢胆固醇的模拟移动床分离研究。通过固定床分离胆固醇和24-去氢胆固醇,分别测定了单根色谱柱的死时间,计算得到色谱柱的总空隙率为0.68,测定了低浓度下胆固醇和24-去氢胆固醇在甲醇中的吸附平衡常数为10.02和7.86;然后基于微分传质方程的通用多组分速率模型,在Matlab^?境下根据有限元正交配置法编制程序求得数值解,继而进行模拟移动床的过程仿真。再参照模拟移动床的计算结果,在实际模拟移动床分离过程中以纯度、生产率和溶剂消耗量为指标,考察了模拟移动床的切换时间、进料流量和进料浓度等因素对分离过程的影响,确定SMB的实验最佳操作条件为:柱温35℃,切换时间为9min,四区流量Q₁为6.5ml/min,Q₂为4.4ml/min,Q₃为4.65ml/min,Q₄为3.0ml/min,进料总浓度2.5mg/ml,经过8周期后,成功地分离了胆固醇和24-去氢胆固醇,相对纯度达到100%和98.5%。更多还原

【Abstract】 Introduced by Broughton and Gerhold in the early 1960s,the Simulated Moving Bed （SMB） appeared predominantly in large scale separations in the petrochemical industry without any attention from fine chemical industry.This changed 15 years ago, when SMB was introduced as a novel technique to separate racemates in early drug development.The role of SMB in pharmaceutical industry has changed dramatically since then.Although SMB is now on its way from an emerging technology to a classical unit operation,the greatest task for the future will be to show that SMB technology is not a sophisticated,technically demanding and unreliable method for separating racemates,but an easy to master tool that can be applied both in early development and in scale-up production.This paper took cholesterol and desmosterol,valuable resources of intermediate for steroids,as study object.The adsorption equilibrium constants of desmosterol and cholesterol were determined as 7.86 and 10.02,respectively,by separating of cholesterol and desmosterol with fixed-bed chromatography.The porosity of chromatograhy columns was 0.68.With these parameters,the region leading to complete separation predicted by triangle theory was able to be drawed out for the choosing of the initiative operating variables.A general multicomponents rate model based on differential mass balance equations is adopted for simulating SMB.According to the outlined numerical solution,results of the simulation program in MATLAB^（?） are shown.Separation of desmosterol from cholesterol by SMB was simulated.The effects of flow rate in section 2（Q₂） and 3（Q₃）,switching time,feed flow rate and feed concentration were studied on the operating performance parameters as purity, recovery,productivity and desorbent consumption.And Operating conditions leading to more than 90%purity in both outlet streams had been identified,together with those achieving optimal performance.Comparison between the results of simulations and the experimentation indicates that the present model describes very well the dynamic behavior of the systems under study.A simple optimization procedure was runned for the choosing the optimal SMB operatingg conditions.Under temperature column of 35℃,switch time 9min,with flow rate of Q₁=6.5ml/min,Q₂=4.4ml/min for,Q₃=4.65ml/min,Q₄=3.0ml/min, cholesterol and desmosterol are separated completely.更多还原