The Study Of Catalytic Active Membrane Microreactor On Esterification Of Acetic ACID With N-Butyl Alcohol

Thermodynamic equilibrium limit reaction is a kind of important reaction in chemical production.For example, esterification, nitration, ketal, acylation reaction, etc. On the other hand, many insufficiencies are accompanied with the productive process, such as low equilibrium conversion, side reaction, difficulty to separation and purification.In order to solve the above problems, for the past few years, Pervaporation Membrane Reactor (PVMR) has been explored as promising Process Intensification approach to solve some of the problems associated with those thermodynamically-limited reactions of interest.Up to now,most of Pervaporation Membrane Reactor researches focused on the development of catalysts and membrane performance optimization.This thesis introduces the concept of microreactor to PVMR design for improving the efficiency of microreactor esterification reaction separation coupling process, With acetic acid and n-butyl alcohol esterification system as the probe reaction.In this study, hydrated Zirconia sulfate[Zr(SO4)2·4H2O] was selected as the catalyst and hydrophilic Polyvinyl Alcohol (PVA), with an average polymerization degree of 1750, was utilized to synthesize the catalytic pervaporation membrane.Composite multi-layer structure of the membrane was produced by the method of immersion-precipitation phase process.Pervaporation catalytic membrane were characterized by scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TG).By optimizing the structure of membrane reactor, we proposed a new type of catalytic pervaporation membrane microreactor. The pervaporation catalytic membrane has a multi-layer composite structure,catalyst scattered on the inner wall of the pore canal of catalyst layer effectively.Tight adhesion between the layers of membrane structure, without stripping phenomenon.Great heat resistance of pervaporation catalytic membrane make the microreactor qualified for the different operations in the appropriate temperature range.The membrane microreactor system exhibited high pervaporation performance. In fact, a 5wt% the water content of a n-butanol/water binary mixture, at reaction conditions of 60℃, and 30 minutes residence time, decreased from 5wt% to 1.4wt%. Yet, the water content in flux to keep at a high level, up to 87.6 wt%. Similarly, in comparison to conventional packed bed reactors, the catalytic membrane microreactor showed high efficiency, with the same catalyst loading, a 60 minutes Residence Time at 65℃ the reaction conversion in the microreactor reached 15.30%,which is twice than the 7.74% that can be achieved in a Packed Bed Reactor under similar conditions of reaction.Furthermore, owing to the reduced volume to area ratio of 0.08 cm3/cm2 for a catalytic membrane microreactor, the esterification reaction conversion at 65℃ reaches 24.76% in 0.75 hours, however, the same conversion can be achieved in 5 hours in traditional catalytic membrane reactor of a volume to area ratio of 12.74 cm3/cm2.