Patent ID: 9598379
Date: 2017-03-21
CPC Classifications: C07D

Claim:
1. A process for preparing melamine by converting urea in the presence of a solid catalyst in one reactor or in a plurality of reactors connected in series in the temperature range from 370° C. to 430° C., cooling the gas formed in the urea conversion in a gas cooler to a temperature from 320° C. to 380° C. and filtering the gas formed in the urea conversion in a hot gas filter, removing the melamine by desublimation and recycling a portion of the gas present after the melamine removal (“cycle gas”) into the reactor or the reactors, which comprises performing all of the above stages at a pressure in the range from 4 bar abs. to 10 bar abs and wherein, after the melamine removal, 5 to 50% of the cycle gas is branched off and fed into the reactor as “fluidizing gas” without passing through a urea scrubber and at least some of the remainder of cycle gas is fed to the urea scrubber.