Urea is the most widely-produced and commonly-traded nitrogen fertilizer. Production amounts to around 150m tonnes a year, of which about 40m tonnes are traded internationally. It is produced in nearly 50 countries worldwide and consumed in every developed agricultural market. The largest producers are Chinese and Indian companies, who have massive domestic markets to serve. The main exporters are producers in areas where feedstock costs are lowest, notably the Middle East, Russia, Ukraine and Caribbean.
An estimated 10-15% of urea manufactured is used in industrial processes, mainly the production of melamine and resins and as an animal feed. The balance is used in agriculture.
Due to primary use being in agriculture, demand for urea is very seasonal. Application takes place either at the time the crop is planted or during the growth phase of the crop, generally this is during the spring season. In the northern hemisphere, this leads to a significant peak in demand in March-April, with a smaller southern hemisphere peak in October-November. The main exceptions to this are in tropical agriculture and the Indian subcontinent, where application follows rainfall patterns. The main application periods in India, for example, are July-September, following the monsoon, and November-December.
Urea contains 46% nitrogen by weight. It is made by combining anhydrous ammonia and carbon dioxide produced in the manufacture of the ammonia. For this reason, urea plants are always located adjacent to upstream ammonia units. The production of one tonne of urea requires 0.58 tonnes of ammonia and 0.76 tonnes of CO2.
Urea is produced initially in liquid form and then generally solidified either through granulation or prilling. Prilled urea is still the most widely-produced form of the fertilizer, but virtually all new urea plants are designed to make granular material. Granular production is expected to outpace prilled production in the next decade. Granular urea has superior handling, storage and spreading characteristics.
Where urea is kept in liquid form it is normally combined with ammonium nitrate to produce a urea ammonium nitrate solution (28-32% nitrogen) for sale to the agricultural sector.
Urea is not considered to be a hazardous substance at normal temperature. It is not flammable and no special precautions are necessary in handling.
To find out more Urea Methodology March 2013