超临界CO_2抗溶剂结晶制备枸橼酸颗粒的产率优化

Optimization of Production Rate for Citric Acid Particle Preparation with Supercritical CO_2 Antisolvent Crystallization

为了进一步提高超临界CO2抗溶剂结晶制备枸橼酸颗粒的操作产率,利用实验室已建的小试装置,依次考察了溶液初始浓度、釜内温度、釜内压力及保压时间对产率的影响。在此基础上,借助均匀设计的实验安排法,实施了产率的工艺优化。结果发现:该操作的产率随釜内温度的增加先增后减,随溶液初始浓度、釜内压力或保压时间的增加而增大,但后期增幅有所趋缓。此外,各因素对产率指标的主次影响顺序依次为溶液初始浓度>釜内压力>釜内温度>保压时间,且在预定的考察范围内,优化的工艺组合为溶液初始浓度0.35 g/mL、操作温度33℃、压力12.5 MPa及保压时间3.5 h,所得产率值可达80%以上。

To further improve the production rate of the citric acid particle preparation with supereritieal C02 anti-solvent crystallization ,using the built small-scale apparatus in lab, the effects of the initial concentration of solution, operation temperature, operation pressure and pressure-holding time on the production rate are investigated in sequence. The technology optimization concerning the production rate is performed with the aid of the experimental arrangement of uniform design. The results show that, the production rate increases firstly and decreases later with the increase of the operation temperature, and increases with the increase of initial concentration of solution, operation pressure or pressure-holding time, but the increasing tendency weakens slowly during the final stage of the operation. Besides, the effect degree order of different factors on the production rate is the initial concentration of solution 〉operation pressure 〉 operation temperature 〉 pressure-holding time, and under the predetermined investigation scope, the optimum technology combination is the initial concentration of solution at O. 35 g/mL, the operational temperature at 33 ~C, the pressure at 12.5 MPa and the pressure-holding time at 3. 5 h, while the corresponding production rate can be over 80%.