Study Of Process Conditions And Intrinsic Kinetics Of Synthesis Of Isopropylphenol By Alkylation Of Phenol With Isopropanol

Isopropylphenol, a kind of important fine chemical raw materials and drug intermediates, is produced with batch reactor in traditional production process. The process is cumbersome, corrosive and difficult to separate, and it's both high energy consumption and low yield.In this article, the continuous alkylated reaction was occurred in an improved gas-solid heterogeneous catalytic device of property evaluation which using phenol with isopropanol as raw materials and ZSM-5 zeolite as catalyst. Not only can this process overcome corrosion to the equipment and high energy-consuming in traditional process, but also getting higher phenol conversion and selectivity to isopropylphenol. The reaction conditions, thermodynamic analysis and the intrinsic kinetics of the process are the main research contents in this article.By means of single factor experiment, the effects of three factors of the phenol/isopropanol molar ratio (0.5:1 to 2:1), reaction temperature (235 to 330?) and space velocity (0.5 to 10h-1) on the conversion of phenol and on the selectivity of o-isopropylphenol and p-isopropylphenol were studied. At the same time, the stability and activity of the catalyst were studied too, and make a characterization to the catalyst. The appropriate conditions were determined by the experimental results and analysis as follows:phenol/isopropanol molar ratio of 1.25:1, reaction temperature of 270? and reaction space velocity of 3h''. The conversion rate of phenol was 40% or more and the selectivity of o-isopropylphenol and p-isopropylphenol was respectively about 7% and about 90%.The main content of thermodynamic study of phenol with isopropanol alkylation reaction over ZSM-5 zeolite catalysts as follows. According to the materials detected by chromatography and mass spectrometry, we can get all the possible reactions, then we can estimate the equilibrium constants and equilibrium conversion rates of all the reactions by Benson group contribution method. Thereby the reaction equations which can reflect their thermodynamic properties were determined and the network structure of the reactions was structured then.The research of dynamics must rule out the internal and external diffusion effect firstly, and then the experiments of alkylation reaction of phenol with isopropanol over ZSM-5 catalyst were carried out under the following conditions:phenol/isopropanol molar ratio of 0.5 to 2 and temperature of 240 to 300?. After that, the main reactions and side reactions using to study the dynamics were determined by variable space velocity experiments, and make a reasonable explanation. According to the experience and related literatures, the exponential type dynamics model was built, and the parameters were valued. The model calculated values were get by numerical integration using MATLAB software. In combination with data obtained from dynamic experiments to optimize the parameters, and finally tested the model, and determined the exponential type intrinsic kinetics equations of alkylation reaction of phenol with isopropanol over ZSM-5 catalyst.