Manufacturing method of 4-heptanone
I. Introduction
4-heptanone is an important organic chemical raw material, which is widely used in the fields of medicine, pesticide, spice, dye and so on. Therefore, it is of great practical significance to study the manufacturing method of 4-heptanone. In this paper, we will introduce a method to prepare 4-heptanone by alcohol-formaldehyde condensation reaction and dehydrogenation reaction using acetone and butyraldehyde as raw materials.
II. Experimental raw materials and equipment
1. Raw materials: acetone and butyraldehyde
2. Equipment: stirring reactor, dehydrogenation reactor, condenser, fractionating tower, etc.
III. Experimental steps
1. Alcohol-formaldehyde condensation reaction
In a stirring reactor, acetone and butyraldehyde were mixed at a molar ratio of 1:1, and acid catalysts were added, and the temperature was raised to 60-80°C for 6-8 hours. During the reaction, samples were taken periodically to check the progress of the reaction, and when the alcohol-formaldehyde condensation reaction was completed, the reaction was stopped.
2. Dehydrogenation reaction
The product obtained from the alcohol-formaldehyde condensation reaction was transferred to the dehydrogenation reactor, dehydrogenation catalyst was added, the temperature was raised to 200-250°C, and the dehydrogenation reaction was carried out under hydrogen atmosphere. During the reaction, keep the system pressure stable and take samples regularly to check the progress of the reaction. When the dehydrogenation reaction is completed, stop the reaction.
3. Product Separation and Purification
The gas in the dehydrogenation reactor was cooled by a condenser and the 4-heptanone product was separated by a fractionating column. The fractions of 4-heptanone were collected and further purified to obtain 4-heptanone with higher purity.
IV. Experimental Results and Discussion
1. Experimental Results
In this experiment, 4-heptanone was successfully prepared by alcohol-formaldehyde condensation reaction and dehydrogenation reaction, with high yield and purity of more than 95%.
2. Discussion of results
In the alcohol-formaldehyde condensation reaction, the type and dosage of acid catalyst have a great influence on the reaction rate and selectivity. The experimental results show that a better reaction effect can be obtained by using appropriate amount of sulfuric acid as catalyst. In addition, the reaction temperature and time need to be optimized according to the actual situation.
In the dehydrogenation reaction, the type and amount of dehydrogenation catalyst also have a large influence on the reaction speed and selectivity. The experimental results show that a better dehydrogenation effect can be obtained by using an appropriate amount of copper-zinc-aluminum catalyst. Meanwhile, keeping the system pressure stable and controlling the hydrogen flow rate are also the key factors for the dehydrogenation reaction.
V. Conclusion
In this experiment, 4-heptanone was successfully prepared by alcohol-formaldehyde condensation reaction and dehydrogenation reaction using acetone and butyraldehyde as raw materials. The experimental results showed that the method has the advantages of high yield and high purity, and has certain prospects for industrial application. Meanwhile, this study also provides a new idea and method for the manufacture of 4-heptanone.
