The n-vinylcaprolactam synthesis reaction is a series of complex reaction systems, and the target product, the raw material and the catalyst all undergo secondary reactions to reduce the utilization rate of the raw materials. The results of the small test showed that when the conversion rate exceeded 30%, the selectivity began to decline. The researchers investigated the synthesis of n-vinylcaprolactam (NVCL) in a jet loop reactor.
The experimental device is mainly composed of a jet, a reactor (volume 8 L), a vortex flowmeter, a dissolution tank, a hot oil pump, and a clean gas tank. The heat supply provides the heat required for the reaction, the hot oil pump provides power for the reaction, and the jet is used to enhance the gas-liquid mass transfer. Experiments have shown that the CL conversion rate in the jet loop reactor is 56.7 percent, and the selectivity of n-vinyl caprolactam (NVCL) is 85.6 percent. The mass transfer efficiency is improved, the residence time of the material in the reactor is shortened, and the secondary side reaction is greatly reduced.
The reaction temperature was observed for n-vinyl at a reaction time of 5 h, KOH addition of 1 g/100 g of raw material, crown ether addition of 0.5 g/100 g of raw material, and n (acetylene): n(N2)=1.5:1. Effect of caprolactam (NVCL) yield and selectivity
It can be seen that as the temperature increases, the conversion rate of raw materials gradually increases, and the selectivity of the product gradually decreases, indicating that a secondary reaction occurs during the synthesis.
The reaction time was observed for n-ethylene at a reaction temperature of 150 ° C, a KOH addition of 1 g/100 g of the starting material, a crown ether addition of 0.5 g/100 g of the starting material, and n (acetylene): n (N 2 ) = 1.5:1. Effect of caprolactam (NVCL) yield and selectivity
It can be seen that as the temperature increases, the conversion rate of raw materials gradually increases, and the selectivity of the product gradually decreases, showing a similar change pattern as the above figure.
On the jet loop reactor, the enhanced mass transfer effect increases the reaction rate. Under the same conversion conditions, the reaction time is shortened and the selectivity of the n-vinylcaprolactam product is increased.