CATALYZED HYDROXYLAMINE PREPARATION

摘要

Method for preparing hydroxylamine in a continuous process, comprising hydrogenating nitrate in a reaction zone comprising a liquid phase, a gas phase and a heterogeneous hydrogenation catalyst, in which reaction zone hydroxylamine and nitrous oxide (N20) are formed, characterized in that the nitrous oxide concentration in the gas phase, is monitored and is maintained within a pre¬ determined range by means of controlled addition of a promoter for the heterogeneous hydrogenation catalyst and/or controlled addition of further amounts of heterogeneous hydrogenation catalyst to the reaction zone until the total amount of catalyst present reaches a pre-determined upper limit; and then (i) withdrawing a fraction of the heterogeneous hydrogenation catalyst from the reaction zone; and (ii) adding one or more further doses of heterogeneous hydrogenation catalyst until the total amount of catalyst present is at most at said pre-determined upper limit; and (iii) optionally repeating steps (i) and (ii); a method for producing an oxime and a method for producing a lactam comprising said process for producing hydroxylamine.