乳状液膜法分离赖氨酸动力学

Kinetics of extraction of lysine by emulsion liquid membrane

目的建立和推导乳状液膜法提取赖氨酸的传质数学模型。方法用实验对传质模型进行验证,取得了较好的一致性。提取赖氨酸的液膜组成:二(2-乙基己基)磷酸(D2EHPA)为载体,Span-80为表面活性剂,液体石蜡-煤油(体积比为1∶1)为膜溶剂。内相选用0.1 mol.L-1的盐酸溶液。固定的实验条件为:膜相与内相体积比(Roi)为1∶1,外水相体积与乳状液体积比(Rwe)为4∶1。结果液膜法提取赖氨酸遵循二级反应动力学。结论在实验条件下乳状液膜提取赖氨酸的过程属扩散-反应双控制过程。

Objective To establish and derive the mathematical models for the mass transfer mechanism of extractions of lysine with emulsion liquid membrane. Methods To verify the mathematical models by experiments. The membrane used for the extraction of lysine was composed of 5 % （w） D2EHPA as the carrier, 5%（w） Span-80 as the emulsifier and a mixture of paraffin and kerosene （V： V= 1： 1） as the solvent. 0.1 mol·L^-1 of hydrochloride solution was used as the internal phase. The operating parameters： The volume ratio of membrane phase to internal phase was 1, the treating ratio were 5. Results Under experimental conditions, the extraction process of lysine could be controlled by both diffusion and reaction processes. Conclusions The reaction order of mass-transfer process is determined from the change of lysine concentratio with time. The results show that the mass-transfer process follows the second order kinetic mechanism.