Study On The Process And Kinetics For Synthesis Of Methyl Carbamate Through Methanol And Urea

This paper introduced main purpose of carbamate ester in organic synthesis as an intermediate, as well as in agriculture, construction, textile industry and other applications. The production methods of carbamate ester were reviewed, focusing on the methyl carbamate's solution with urea and alcohol, seting up a dynamic model and analysising preliminary reaction mechanism.(1) This test reactor was used in high pressure conditions with magnetic stirring devices, temperature control, temperature, pressure measurement devices. Methanol gas could be condensed into a liquid in a timely manner because of the condensation reflux device in the reactor. That was conducive to the chemical reaction. The gas chromatography analysis has been set up. This test reactor used liquid evaporation-the process of extraction, urea Ehrlich reaction, with act spectrophotometer measured the concentration of urea.(2) The enviromental-friendly process of methyl carba-mate from urea was systematically investigated whitch covers the factors of temperature, quantity of catalyzer, reaction time, ratio he materials. The best synthetic conditions are as follow.Urea and alcohol inmole ratio 10:1 at 145℃for 2.5h, catalyst amount is 8.11% and the rotate speed is 200s/m.The yield of methyl carbamate is 73.58%.(3) Reduced pressure distillation and Qi Shi tube method measuring the melting point of products was to determine the purity of the product. Melting range was about 5℃. Preliminary MC is not very high purity, and recrystallization could be considered on in the follow-up steps.(4)Preliminary reaction Mechanism was analysised.The dynamic model was calculated for the first time.No catalyst and PPA catalyst for the reaction order is all 3. Activation of performance was:80.339kJ/mol,65.313kJ/mol. This shows that the PPA as a catalyst for the reaction of the lower activation energy 15.026 kJ/mol. The relationship between catalyst content and the rate constant is k=9.5884 [cat]+0.1454, through lots of trials. This article provided some basic research for the project.