GB877947A - Improvements in or relating to a process for the production of hydrocyanic acid - Google Patents

Abstract

In the preparation of hydrocyanic acid by vapour phase reaction of a mixture comprising ammonia, a hydrocarbon, e.g. methane, or a mixture of hydrocarbons and oxygen which mixture contains less than 1 mg. S. per M3, over a platinum metal or platinum metal alloy catalyst at elevated temperature, a volatile S-containing material is added to the reactants in amount such that the content is 1-500 mg of S per M3 and the free oxygen content of the mixture is adjusted to obtain maximum conversion of the ammonia and hydrocarbon to hydrocyanic acid. Hydrocarbon/ammonia volume ratios calculated on the amount of methane equivalent in carbon content to the total hydrocarbon present are preferably 0.7:1 to 1.4:1. Volatile S-containing materials specified are carbon disulphide, hydrogen sulphide and thiophene which may be added to the reactants in any convenient manner, e.g. prior to entry into the reactor, directly in the reactor, or into a stream or volume of one of the reactants which is then added to the main feed stream. The use of coke oven gases as a source of the volatile S-containing material is also referred to.