Urea occurs as white hygroscopic crystals, which are either odourless or have a slight smell of ammonia. Urea is not considered to be harmful at normal temperature, but the dust may irritate the skin, eyes and nose.
The major outlet for urea, accounting for nearly 90% of total consumption, is as a fertilizer. Urea is also used in the manufacture of urea-formaldehyde resins, the synthesis of melamine, in adhesives and paints, and for laminates, moulding compounds, impregnating paper and textiles.
Urea is widely traded on international fertilizer markets. There are two main hubs in urea trade – the Black Sea and Arab Gulf. These flows are said to determine the global urea prices.
Urea production involves a two step process where the ammonia and carbon dioxide react to form ammonium carbamate which is then dehydrated to urea. In the process, ammonia and carbon dioxide are fed to the synthesis reactor which operates around 180-210oC and 150 bar pressure.