催化精馏合成乙二醇乙醚的研究

催化精馏是将固体催化剂布于精馏塔内,它既加速了化学反应,又可作为分离过程的传质表面。本文研究了在内径为35mm的不锈钢塔中,用NKC—01催化剂从乙醇和环氧乙烷合成乙二醇乙醚(单醚)的过程,详细考察了进料比,操作压力,处理量等因素对过程的影响,找到的适宜条件为:进料比(乙醇/环氧乙烷)=6～8(摩尔);处理量为104.0Nm~3环氧乙烷/h(m~3催化剂);操作压力=2.35×10~5Pa。在此条件下乙二醇乙醚对环氧乙烷的收率为90％(mol);环氧乙烷的单程收率为93％;乙二醇乙醚的选择性为97％。为考察塔内的流体力学条件对催化反应的影响,在搅拌容器中测定了过程的反应动力学。为保证此搅拌容器中的液体流速接近塔内操作条件下的流速,以确定适宜的搅拌器转速,我们用DANTEC MODEL 2020激光测速仪测定了不同搅拌器转速下容器中液体的流速。通过研究可以看出:在塔内的操作条件下,与化学反应相比,扩散阻力可以被忽略。

Study on Synthesis of 2-Ethoxyethanol Using Catalytic Distillation

In this paper a catalytic distillation process for producing 2-ethoxy-ethanol from ethylene oxide (EO) and ethanol(EtOH) with NKC-01 spherical catalyst in fabric was investigated using a column with inside diameter of 35 mm. The composition of product was analyzed by an internal standard method on a gas chromatography model SP-2305. The effect of molar ratio in feed, throughput and operational pressuree were inspected. Based on the experimental results, the suitable operating condition is presented as follows:operational pressure is 2. 35 E+05 Pa, throughput 104(Nm3 of EO)/(h) (m3 catalyst) and molar ratio(EtOH/EO)6-8. Under this condition the yield of 2-ethoxyethanol with respect to EO is about 90% (mol),conversion of EO 93% and selectivity 97%.In order to consider the influence of hydrodynamic condition within the column on catalytic reaction, the reaction kinetics was studied in an agitated tank. The speed of liquid flow in this tank with different rotating speed of stirrer was measured by a laser tachometer of DANTEC MODEL 2020 to ensure it equals the speed of liquid flow within the column. It is observed that the diffusion resistance can be neglected relative to that of chemical reaction under this operation condition.