Hoechst Aktiengesellschaft

Reinhold Graser

Adolf Metzger

Wilhelm Lendle

Hendrik W Post

Heinz Karl Hofmeister

Rolf Konrad

Ammonium sulfamate is prepared continuously, starting from ammonia and sulfur trioxide, by introducing liquid sulfur trioxide and liquid ammonia in a molar ratio NH.sub.3 /SO.sub.3 greater than 2.0:1 into a pressure reactor containing molten reaction product. Excess ammonia is removed continuously from the reactor. The liquid sulfur trioxide is introduced into the melt, while the liquid ammonia is fed onto the surface of the melt.

Process for the preparation of ammonium sulfamate

German published patent application 2,710,399 discloses a process for the manufacture of ammonium sulfamate involving introducing sulfur trioxide and ammonia into a pressure vessel containing a melt that mainly consists of ammonium sulfamate and ammonium imidosulfamate, while maintaining a molar ratio between NH.sub.3 and SO.sub.3 from 1.5:1 to 1.99:1. It has now been found that the pressure vessel is suitably released from pressure for a short period of time after prolonged reaction times to discharge thus the main quantity of the collecting inert gases.

Process for the manufacture of ammonium sulfamate

Crude monochloromethane is freed from dimethylether by a washing with aqueous hydrochloric acid.

Purification of crude monochloromethane gas

Ammonium sulfamate is prepared by introducing sulfur trioxide and ammonia into a pressure vessel that contains a melt essentially consisting of ammonium sulfonate and ammonium imido disulfonate using a molar ratio of NH.sub.3 to SO.sub.3 of 1.5 to 1.99:1. The gases that accumulate on top of the molten phase are not removed from the pressure vessel.

Process for preparing ammonium sulfamate

When sulfur trioxide is reacted with ammonia, a melted reaction product containing mainly the ammonium salts of amidosulfonic acid and imido-disulfonic acid is obtained. According to the invention the melted reaction product is introduced into mineral acids. From the resulting solution, free amidosulfonic acid precipitates in high yield.

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Frankfurt am Main, Germany

Reinhold Graser