| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 102 === The heterogeneous kinetics behavior was investigated with a batch reactor for the synthesis of ethyl levulinate from levulinic acid and ethanol over cation-exchange resins, Amberlyat 39. The experiments were conducted at tempertures from 328.15 K to 348.15 K. Additionally, the effects of molar ratio of ethanol to acid in the feed stream, the mass transfer resistances on the catalytic reaction, and the different levels of catalyst loadings were also observed.
The reaction rate of acid increased with increase of reaction temperature, molar ratio of ethanol to acid in the feed stream, catalyst loading, and rotational speed. Moreover, the equilibrium conversion of acid increased with increase of reaction temperature and molar ratio of methanol to acid in the feed stream. The relative adsorption strengths of the reacting species were determined by adsorption experiments. The results indicated that the magnitude of adsorption strengths on Amberlyst 39 followed the order of water > ethanol > levulinic acid > ethyl levulinate .
The kinetic data of the synthesis of methyl levulinate were correlated with the ideal-quasi-homogeneous (IQH), the non-ideal-quasi-homogeneous (NIQH) the Eley-Rideal (ER), the Langmuir-Hinshelwood-Hougen-Watson (LHHW) and the Langmuir-Hinshelwood-Hougen-Watson with Ka (LHHW-Ka) models, respectively. The optimal values of the kinetic parameters were determined from the data fitting. The NRTL model was used to calculate the activity coefficients for each reacting species. The LHHW model yielded the best representation for the kinetic behavior of heterogeneous catalytic synthesis of ethyl levulinate.
|
|---|
