Rapid continuous flow synthesis process of fluoroethylene carbonate

Abstract

The invention relates to a rapid continuous flow synthesis process of fluoroethylene carbonate and an integrated continuous flow reactor for realizing the process. The continuous flow synthesis process is characterized in that a raw material to be fluorinated and fluorine gas are used as reactants, and are continuously and successively subjected to steps of mixed dispersion, fluorination reaction,gas-liquid separation, so as to obtain the fluoroethylene carbonate; and the synthesis process is carried out in the integrated continuous flow reactor, the raw material to be fluorinated and the fluorine gas are continuously added to a feed inlet of the integrated continuous flow reactor, and the fluoroethylene carbonate is continuously obtained from a discharge port of the integrated continuousflow reactor with the reaction time equal to or less than 600 s. The process is a rapid, safe, efficient, highly versatile and easy for mass production continuous synthesis process of the fluoroethylene carbonate.

Description

technical field [0001] The invention relates to the field of chemistry, in particular to a rapid continuous flow synthesis process of fluoroethylene carbonate. Background technique [0002] Fluorine-containing compounds, especially organofluorine compounds, ie partially and fully fluorinated organic compounds, are high-performance, commercially valuable chemicals. Fluorine-containing compounds can exhibit various properties such as inertness, non-polarity, hydrophobicity, oleophobicity, etc., and thus have a very wide range of uses. Fluorinated organic carbonates are an important class of organic fluorine compounds (organic organic fluorides), which can be used as solvents and solvent additives for lithium-ion batteries. They have better performance in forming solid electrolyte interface films (SEI films), and can It forms a compact structure layer without increasing the impedance, and at the same time, it can prevent the further decomposition of the electrolyte and has a f...

AI Technical Summary

Problems solved by technology

Although this method realizes continuous, there are still the following main problems: the one, technological operation is loaded down with trivial details and complexity, needs to be filled with inert liquid reaction medium in advance in the reactor, needs to fill the reactor by replenishing liquid (recovery or new) in the process The quality of the inert liquid medium is kept at a constant level; the second is that the reaction time is long and the reaction efficiency is low. It takes several hours or even more than ten hours to inject only 100 grams of samples to complete the fluorination process, which greatly limits the expansion of production scale.

The main problem is that the circulating fluorination time of the reaction mixture in the reactor is too long, it takes several hours to several days, even several weeks, the reaction efficiency is very low, and the direct fluorination cannot be completed in a short time (within 10 minutes). reaction, and did not solve the problems of poor controllability, mass transfer, flexibility and poor selectivity in the direct fluorination method

That is to say, in order to meet the heat and mass transfer requirements of the fluorination reaction, the reaction device is equipped with a variety of auxiliary equipment, which has a low degree of integration and a complex structure.

In short, the reaction device is not an integrated continuous flow reactor, and must be cascaded by multiple reactors to complete the reaction

[0029] The second is that the residence time is still relatively long, and the reaction time of this method is at least 30 minutes

[0030] The third is that the operation of the process is complicated. For example, it is mentioned that each substance in the reaction mixture needs to reach a certain "static concentration" before the reaction can proceed smoothly. A fixed concentration that needs to be maintained, and it takes a certain period of time after the reaction is started to reach the requirement of this "static concentration"; during the reaction, the reaction mixture needs to be drawn from each cascade reactor, and the amount of the mixture and each component The concentration needs to maintain a certain proportional relationship with the feed amount; during the process, the material needs to stay and wait in each reactor and the waiting time is different, it is not a continuous flow, not a continuous flow process; the same reactor is synthesizing For fluoroethylene carbonates with different degrees of fluorination, the waiting time for materials to exotherm in them is also different

In addition, the above-mentioned process requirements have increased the difficulty of overall process control and production site operation.

[0031] Chinese patent CN201080042843A relates to the use of a cascade of reactors similar to the above to realize the synthesis of polyfluoro (difluoro, trifluoro and tetrafluoro) ethylene carbonate and corresponding mixtures. The above three problems also exist in the device and process, such as The materials need to stay and wait in each reactor and the waiting time is different, and the waiting time of the materials in the same reactor is also different when synthesizing fluoroethylene carbonate with different degrees of fluorination

If it is not resolved, it will lead to great uncertainty in the production process and product quality. First, the quality of downstream products will be directly unstable and difficult to control; Effectively control the production process, so that production safety cannot be guaranteed, burying many safety hazards for the production process

[0033] To sum up, the direct fluorination reaction has relatively strict requirements on the mass transfer, heat transfer, and safety of the device and process. Due to the limitations of the device and process, the existing technologies have problems of complex devices and cumbersome processes to varying degrees. This leads to the problems of long reaction time, low production efficiency, process and device flexibility, and poor selectivity.

For the synthesis of fluoroethylene carbonates with different degrees of fluorination, no production process has been developed that can give full play to the reaction advantages of the direct fluorination method and overcome the above three shortcomings of the method, namely: fully solve the problem of heat transfer , mass transfer issues, and flexibility and selectivity issues that take into account the physical properties of different raw materials (such as melting and boiling points, thermal conductivity, heat capacity, solubility, etc.) and reactivity differences

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