GB958776A - Improvements in and relating to a process for producing hydrazine - Google Patents

Abstract

In a process for producing hydrazine from ammonia, a gaseous phase is subjected to an electric discharge in the presence of a finelydivided liquid phase, at least one of the liquid and gaseous phases containing ammonia. The liquid may be anhydrous liquid ammonia at - 70 DEG C. or aqueous ammonia at - 50 DEG to 0 DEG C. or higher if it has ammonium nitrate dissolved therein. The liquid may be forced through nozzles, or against a surface, spun from the edge of a rotating disc, contacted with an/ultrasonically vibrating surface, or atomized by a stream of gas, to produce droplets having a diameter between 0.2 and 2 mm., and may be passed through the discharge several times to increase its hydrazine content. The gas may consist predominantly of argon, or only of vapour in equilibrium with the liquid but is preferably a mixture containing gas passed as such into the discharge region where its temperature is below 300 DEG C. The pressure is preferably between 5 and 100 mm. of Hg and the field strength between 25 and 1500 volts per cm., with a current density below 0.5 amps. per cm.2. The discharge may be between a wire and a cylinder but is preferably in a uniform electric field. Cooling may be effected by the circulation of gas or liquid moving as a film over the electrodes or vessel walls. The electrodes may be of platinum, tungsten, nickel, stainless steel, or chromium- or nickel-plated copper or copper alloys and may be hollow for circulation of cooling fluid, and may have a nozzle through which the liquid phase is sprayed along the axis of the discharge. A catalyst to promote the recombination of hydrogen atoms may be present in the reaction system. A specific example is given. According to the Provisional Specification, a similar process may be used for producing hydrogen peroxide from water. Specification 958,778 is referred to.