Preparation of hydrazine hydrate by ketazine method

(3) Ketone method

The ketazine method, also known as the BergbauBayerWhiffen method, was developed in the 1960s and was first patented by Bergbau Farsching, an affiliate of the German Coal Mine Association.

①In the presence of fatty ketones, NaCIO is used to oxidize ammonia to obtain hydrazone, azide or isohydrazone

② After the oxidant is completely consumed, the intermediate is concentrated and then hydrolyzed into hydrazine and hydrazine salt

The Bayer process involves the reaction of acetone , oxidant chlorine or sodium hypochlorite with ammonia to produce the intermediate ketazine

2NH ₃ +NaOCl+2CH ₃ COCH ₃ →(CH ₃ ) ₂ C=NN=C(CH ₃ ) ₂ +NaCl+3H ₂ O

The process flow is shown in Figure 12-3

Figure 12-3 The process flow of producing hydrazine hydrate by the ketazine method

In the Japanese process, in the presence of ketones, Ca(ClO) ₂ reacts with ammonia to produce ketazine, which is then hydrolyzed to obtain calcium ketone of hydrazine hydrate

In view of the disadvantages of the Bayer process, such as the large amount of ammonia and the low concentration of hydrazine in the hydrolysate, the Southwest Research Institute of Chemical Industry of China has developed a catalytic oxidation process for hydrazine production: the rare earth-silica gel hypochlorite compound codenamed CL-5 is used as a catalyst catalyst addition amount of 0.