Method for preparing hydroxylamine

Abstract

A method for preparing hydroxylamine by reducing nitric acid or its salt with hydrogen gas in an aqueous medium in the presence of a catalyst, wherein reduction of nitric acid or its salt is performed in a reactor comprising a reaction section, a cooler disposed at the lower portion of the reactor, and a middle gas distributor and a lower gas distributor respectively disposed above and below the cooler for introducing hydrogen gas into the reaction section. According to the present invention, gas distribution become more uniform by disposing the gas distributors at different positions of the reactor, which results in higher yield of hydroxylamine.

1 - 9 . (canceled) 
     
     
         10 . A reactor for preparation of hydroxylamine, in which the preparation is performed by reducing nitric acid or its salt with hydrogen gas in an aqueous medium in the presence of a catalyst, and unreacted hydrogen gas is recovered, the reactor comprising:
 a reaction section;   a cooler disposed at a lower portion of the reactor;   a lower gas distributor disposed below the cooler and configured for introducing a first fresh hydrogen gas into the reaction section; and   a middle gas distributor disposed above the cooler and configured for recovering and circulating the unreacted hydrogen gas back to the reaction section.   
     
     
         11 . The reactor according to  claim 10 , wherein the middle gas distributor is configured for introducing a mixture of the unreacted hydrogen gas and a second fresh hydrogen gas. 
     
     
         12 . The reactor according to  claim 10 , further comprising an upper gas distributor disposed above the middle gas distributor and configured for introducing part of the first fresh hydrogen gas and the rest of the first fresh hydrogen gas is introduced into the reaction section through the lower gas distributor.