Study on Synthetic Process and Kinetics of Hydroxypivalaldehyde
1. Technology Research Institute of Shanghai Huayi Group, Shanghai 200241, China;
2. Chemical Engineering Institute, East China University of Science and Technology, Shanghai 200237, China;
3. Computational Chemistry and Chemical Engineering Technology Research Center of Shanghai, Shanghai 200241, China
Abstract Hydroxypivalaldehyde (HPA) is an important intermediate for synthesizing many fine chemicals. In this paper, orthogonal design was used for the process conditions optimization of synthesizing hydroxypivalaldehyde by condensation reaction with formaldehyde and isobutylaldehyde using organic amine aqueous solution as catalyst. The reaction kinetics was also studied and the optimal reaction conditions were found to be as follows: catalyst loading 3%, reaction temperature 75 ℃, molar ratio of formaldehyde to isobutylaldehyde 1.1:1, reaction pressure 0.3 MPa and the reaction time 80 min, under which the HPA yielded 98.33%. The kinetics experimental results further indicated that the apparent activation energy for this condensation main and side reaction were 40.80 kJ/mol and 64.09 kJ/mol respectively, and the reaction orders for isobutyraldehyde, formaldehyde and hydroxypivalaldehyde were 1, 1.2 and 2 respectively. Both residual analysis and the statistic tests showed that the proposed kinetic models were reliable.
