What is biuret? How to control it?
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This post was last edited by lxq700918 on 2009-5-4 12:59. What is biuret? How to reduce biuret in finished urea?
Biuret is an indicator for controlling the quality of urea products; a low value is desirable. What the poster is referring to in their question is probably cyclodicyanamide
The biuret reaction is expressed as 2(NH2)2CO = NHCONH2CONH2 + NH3. It results from the condensation of two urea molecules at high temperatures and low ammonia partial pressures, with one molecule of ammonia being released in the process; this ammonia is harmful to crops, especially their leaves. During production, it is important not to exceed the specified temperature limits and to minimize the time that the material is exposed to high temperatures and low ammonia partial pressures. This helps to control the rate of biuret formation. The standard limit for biuret content in products is usually 0.9–1.0%. I’m not sure what the biuret content is in your products.
Is the poster saying that during evaporation washing or fluctuations, the biuret adhering to the inner walls of the equipment is washed away, and larger particles can clog the pipes?
Biuret is formed by the dehydration condensation of two molecules of urea; the reaction formula is: 2(NH2)2CO = NHCONH2CONH2 + NH3. Reducing the formation of biuret can be achieved through the following approaches: 1. The N/C ratio of the control system should not be too low; 2. The system load should not be too low; 3. Evaporation temperature; 4. Residence time; 5. Urine concentration, etc.
This post was last edited by lxq700918 on 2009-5-5 20:22. The reaction equation for biuret is: 2(NH2)2CO = NHCONH2CONH2 + NH3. Theoretically, the formation of biuret increases as the ammonia partial pressure decreases, the temperature rises, and the residence time increases.
Try to keep the temperature of the urine within acceptable limits, and maintain a low level of urine to reduce the time it stays there.
Biuret is a by-product of the urea synthesis process; it is primarily influenced by temperature and the ammonia-to-carbon ratio. Excessively high temperatures lead to an increase in this by-product. Even if the concentration of ammonia during synthesis is too low, biuret levels still rise! ! !
By-products in urea production; controlling residence time, concentration, and ammonia partial pressure.
Dicyandiamide is a product of the urea condensation reaction; the use of urea serves primarily to increase the nitrogen content and reduce moisture levels. Dicyandiamide has adverse effects on plants, and it is produced mainly due to excessive temperature control and prolonged residence time after urea synthesis.