Method for producing solid urea by granulation

Abstract

Method for producing solid urea by granulation, wherein the granulation is fed with liquid urea having a purity greater than 98% by weight and not containing formaldehyde.

1 ) A method for producing solid urea by granulation, wherein the granulation is fed with urea melt having a concentration of more than 98% by weight and in that no formaldehyde is added to said urea melt. 
     
     
         2 ) The method according to  claim 1 , wherein said urea melt has a concentration of at least 99.5% by weight. 
     
     
         3 ) A plant for producing solid urea in granule form, operating using a method according to  claim 1 . 
     
     
         4 ) Solid urea in granule form, free from formaldehyde, obtained with a method according to  claim 1 . 
     
     
         5 ) A method for revamping a plant for producing solid urea, wherein the plant comprised a prilling section for production of solid urea by means of prilling of a high-concentration urea melt, the method comprising the steps of:
 installing a granulation section and feeding at least part of said urea melt originally intended for the prilling section, and without the addition of formaldehyde, to said new granulation section.   
     
     
         6 ) The method according to  claim 5 , wherein a portion of said urea melt is used in the prilling section to produce seeds for said new granulation section. 
     
     
         7 ) The method according to  claim 1 , wherein said urea melt has a concentration of at least 99.7% by weight.