Apparatus and method for preparing poly-gamma-butyrolactone by using urea and alkoxide

Abstract

The invention discloses an apparatus and a method for preparing poly-gamma-butyrolactone by using urea and alkoxide. Main and auxiliary reaction kettles are respectively provided with a solid feedingport, a liquid feeding port, main and auxiliary vacuum ports, main and auxiliary air inlets and main and auxiliary discharge ports. The lower part of the auxiliary reaction kettle body is further provided with a liquid discharge port connected to a constant-pressure dripping device through a pipe. A liquid inlet end of a closed container of the constant-pressure dripping device is connected in parallel with a vacuum port of the dripping device, and a pipeline of a liquid outlet end of the closed container is provided with a liquid adding valve and a dripping valve. The upper end of a bypass branch pipe of the constant-pressure dripping device is connected with the upper half of the closed container, and the lower end is connected to a pipeline between the liquid adding valve and the dripping valve. The three vacuum ports are all connected to vacuum-pumping equipment, and the two air inlets are both connected to nitrogen-adding equipment. Due to the adoption of the main and auxiliary reaction kettles and the constant-pressure dripping device and by combining the vacuum-pumping equipment and the nitrogen-adding equipment, oxygen is isolated and materials can be continuously added, the harsh condition of ''adding in a dripping manner under water-free and oxygen-free conditions'' is met, and there is no safety hazard.

Description

technical field [0001] The invention relates to the field of reaction kettles used in the chemical industry, in particular to a device and method for preparing poly-γ-butyrolactone by utilizing urea and alkoxide. Background technique [0002] The advancement of science and technology has promoted the development of the chemical industry, but safety issues in the chemical synthesis process have also emerged one after another. For example, the explosion incidents in the Dalian Chemical Plant and the Yancheng Chemical Plant Explosion in Jiangsu have highlighted the importance of safety in the reaction process. [0003] In this paper, urea and alkoxide, the R and R` groups in urea are aliphatic groups, phenyl or cycloalkyl groups, and the U2 urea structure has the highest activity, and the alkoxide is an alkali metal alkoxide, and the alkali metal is lithium , sodium or potassium, alcohol is methanol, ethanol or benzyl alcohol, most of the urea structure and alkoxide have been c...

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Problems solved by technology

[0004] However, none of the existing reactor structures can meet the harsh conditions of "slowly dripping under anhydrous and oxygen-free conditions"; and the mixture of urea and alkoxide is prone to spontaneous combustion when exposed to the air for a long time, and there are certain safety hazards

[0005] Therefore, prior art still needs to improve and develop

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