Studies On Preparation Of 3-hydroxypropanal By Acrolein Hydration

Acrolein hydration is an acid-catalyzed reaction, it is the key step towards thesynthesis of 3-propanediol from acrolein.Ion-exchange resins and other solid acid catalyst are used in acrolein hydration,but there are disadvantages such as low activity and poor stability of the catalyst.The literature shows that zeolite and solid inorganic acids catalysts maybe moreefficient. However the studies about these are few and a suitable catalyst for thishydration has yet to be developed. So we begin the research on liquid acid-catalyzedacrolein hydration to find the optimum conditions, including the acid type, acidity,and other factors affecting hydration. In this acrolein hydration, catalyst study, wewant guidance on the design and preparation a catalyst, to raise the reactivity andselectivity.Phosphoric acid, sulfuric acid and phosphoric and triethylamine buffer wereused as a catalyst for the hydration of acrolein, the basic conditions weresystematically studied, and factors such as temperature, time, pH, types of acid wereresearched. The results showed that the effect was influenced by acidity to a certainextent, and hydrogen ion activity regardless of its source. The results also showedthat buffer solution as a catalyst was better than a single-acid catalyst.When strong acidic resin was used in acrolein hydration, as a strong acid catalyst,the reaction required a low temperature to proceed, and had a higher conversion, butwith lower selectivity. In a flask reactor, over a long period of time, acroleinconversion and 3-HPA selectivity reach to 60.00% and 63.01%; In a continuousreaction method, they reach 45.57%, 65.24%.In a fixed-bed continuous reactor, while using chelating resin 850 in hydration,the conversion rate was 58.85% and the selectivity of 3-HPA was more than 92%, so its yield could be 54.39%. The data of conversion and selectivity show that suchresin is more suitable for 3-HPA industrial production.