Process for preparing trifluoroacetaldehyde hydrate from 1,1,1-halothane

Abstract

The invention discloses a process for preparing trifluoroacetaldehyde hydrate from 1,1,1-halothane. The process comprises the following steps of preheating a raw material mixture consisting of 1,1,1-halothane, oxygen gas and nitrogen gas; then, injecting the mixture into a fixed bed reactor; using Fe2O3 / AlF3 or CuO / AlF3 as a catalyst; performing reaction at 0.1 to 3 mPa at 100 to 500 DEG C, wherein the reaction is continuously performed; adsorbing products at an outlet; and separating out the trifluoroacetaldehyde hydrate. The process for preparing the trifluoroacetaldehyde hydrate provided by the invention has the advantages that the conversion rate of the 1,1,1-halothane can reach 16 to 39 percent; the selectivity of the trifluoroacetaldehyde hydrate can reach 20 percent or higher; through the process, the 1,1,1-halothane can be directly converted into the trifluoroacetaldehyde hydrate; the reaction process is simple; the product can be easily separated; the purity of the obtained trifluoroacetaldehyde hydrate can reach 95 percent or higher. The trifluoroacetaldehyde hydrate capable of being applied to important chemical products can be prepared and produced at high efficiency and low cost.

Description

Technical field [0001] The invention belongs to the technical field of chemical engineering, and relates to a preparation process of trifluoroacetaldehyde hydrate, in particular to a process for preparing trifluoroacetaldehyde hydrate from 1,1,1-trifluoroethane. Background technique [0002] 1,1,1-trifluoroethane has been gradually banned as a third-generation refrigerant due to its high greenhouse effect potential. Therefore, how to convert it into higher value-added chemicals to solve its problem The current situation of large production capacity is an urgent problem to be solved. [0003] Because trifluoroacetaldehyde contains both trifluoromethyl and aldehyde groups in its molecule, it is widely used in synthetic resins, functional polymer materials, rubber, coatings, medicine, pesticides and other industries. However, because it is gaseous at room temperature and easily combines with water to form hydrates, it is difficult to prepare, produce or transport. At present, there a...

AI Technical Summary

Problems solved by technology

However, because it is gaseous at room temperature and easily combines with water to form hydrates, it is difficult to prepare, produce and transport. At present, there are few studies on the preparation of trifluoroacetaldehyde hydrate, and no mature products have been produced. Production Technology and Process

[0004] U.S. Patent US3038936 and Hideyuki Mimura's research group in Japan have successively reported the preparation of trifluoroacetaldehyde by oxidizing 2,2,2-trifluoroethanol. The raw material 2,2,2-trifluoroethanol used in this process is expensive and difficult , which makes the cost of preparing trifluoroacetaldehyde higher

In addition, Pierce and Kane et al. reported the preparation of trifluoroacetaldehyde by liquid-phase reduction of 2,2,2-trifluoroacetate. This process needs to be carried out under anhydrous and low temperature (-70°C) conditions, using LiAlH 4 As a reducing agent, the process has harsh reaction conditions and is not suitable for industrial production

[0005] The above-mentioned process has problems such as expensive raw materials, complex process, harsh reaction conditions, and high cost of product separation in the later stage.