초록 ▼

The process of producing from urea a reaction product which is predominantly cyanuric acid, which process involves only the application of heat without use of solvents or catalysts. The process in its first stage involves heating molten urea for a time and at a temperature to convert the urea to a f

The process of producing from urea a reaction product which is predominantly cyanuric acid, which process involves only the application of heat without use of solvents or catalysts. The process in its first stage involves heating molten urea for a time and at a temperature to convert the urea to a first stage reaction product comprising less than 40% urea and at least 30% biuret, then cooling and comminuting the first stage reaction product, then as a second stage of the process, passing hot air through the comminuted first stage reaction product at temperatures progressively increasing but maintained below the melting point of the reaction, such solid phase heating of the reaction product during the second stage of the process being maintained until the cyanuric acid content is at least about 50% of the final reaction product and is preferably at least about 70%.

대표청구항 ▼

A process in which urea is pyrolytically converted to cyanuric acid, said process comprising heating, in dry, particulate, and essentially solid state, a partially pyrolyzed reaction product containing less than about 40% urea by weight an at least from about 30% biuret by weight, the heating of suc

A process in which urea is pyrolytically converted to cyanuric acid, said process comprising heating, in dry, particulate, and essentially solid state, a partially pyrolyzed reaction product containing less than about 40% urea by weight an at least from about 30% biuret by weight, the heating of such feedstock occurring while maintaining the particles in essentially solid phase and at a temperature substantially at or slightly below the softening temperature of the particles with forced hot gas flow interstitially through the particles for a sufficient time to increase the cyanuric acid content thereof until the reaction product is principally cyanuric acid, partly by conversion of urea to biuret and in turn by conversion of biuret to cyanuric acid.