Study On The Synthesis Of Methallyl Alcohol From Formaldehyde And Propionaldehyde

Methylallylalcohol is not only an important organic intermediate,but also an important additive,which widely used in industrial products and food additives fields.The synthesis of methylallylalcohol from methylacrolein,which prepared by formaldehyde and propionaldehyde,was researched in this topic.Firstly,methylacrolein was preparated by formaldehyde and propionaldehyde through the process route of Mannich reaction liquid phase condensation,and characterized by FTIR spectra.The optimum process conditions were obtained:reaction time=40min;reaction temperature=100?;the mole ratio of formaldehyde/propionaldehyde/organic amine/glacial acetic acid=1.1/1/0.025/0.015;the amount of polymerization inhibitor=0.1%of the total mass.Using this process conditions,conversion of propionaldehyde was 99.29%and yield of methylacrolein attained 92.57%.Then,the product system of methacrolein separated by using Aspen Plus.Selecting two RadFrac models Tland T2 to separate the system.The experimental conditions were as follows:number of stages by T1 and T2 was 36 and 41,feed stage was 17 and 21,and reflux ratio was 1.1 and 5.93.The separation results was the purity of methacrolein reached 99.4%,which was the product of bottom,and the product of top was formaldehyde and propionaldehyde,the purity was 68.3%and 28.7%,can using the next experiment.Finally,the Ir-Re catalysts were prepared and used to produce methylallylalcohol from methylacrolein hydrogenation,which were loaded on Al2O3 or SiO2 carrier.Through the study of the performance of the catalyst,selecting the better performance of the catalyst Ir-Re/SiO2-1.5,which were characterized by XRD and TEM.The influence of reaction temperature,reaction pressure and the concentration of raw material were researched.