Also known as carbamide, is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO.
Urea is produced commercially from two raw materials, ammonia and carbon dioxide. Large quantities of carbon dioxide are produced during the manufacture of ammonia from coal or from hydrocarbons such as natural gas and petroleum derived raw materials. This allows direct synthesis of urea from these raw materials. It is widely used as fertilizer as an efficient source of nitrogen and also as a raw material for the chemical industry.
Urea has a number of advantages over other nitrogen fertilizers. Urea is safer to ship and handle, it is less corrosive to equipment, it has a higher efficiency than any other dry nitrogen fertilizer and it can be used on virtually all crops. Urea can be stored and distributed through conventional systems. It can be applied in many different ways from sophisticated aerial application equipment to a farm spreading urea by hand. Urea is also highly water soluble so it moves readily into the soil. The higher analysis means a reduced transportation and application cost per kilogram of nitrogen which makes it a very efficient mode of fertilizer on a global scale.
WHAT IS UREA
Urea is a white dry organic compound and a crystalline substance and has minimum of 46% Nitrogen calculated in dry state.
This has the melting point of 132 deg F.
HOW IS UREA MADE
Urea is made by reacting carbon dioxide (CO2) with anhydrous ammonia (NH3) under pressure of 3000 psi and temperatures of around 350 deg F. Water is removed during processing and the molten matter is either converted to prills or into granules.
SHAPE OF UREA
It is generally supplied in prills or crystals/grains . Although the colour of urea is white but the crystals are larger than prills. It can also be produced as flakes, pellets, crystals and solutions.
Urea is a nitrogen-containing chemical product which is produced in excess of 140,000,000 tons per year worldwide, of which more than 90% of world production is destined for use as a fertilizer.
Urea has the highest nitrogen content of all solid nitrogeneous fertilizers in common use (46.4%N.) which is the highest concentration dry nitrogen fertilizer available. It therefore has the lowest transportation costs per unit of nitrogen nutrient.
Urea is highly soluble in water and is therefore also very suitable for use in fertilizer solutions (in combination with ammonium nitrate: UAN), e.g. in “foliar feed’ fertilizers.
OTHER INDUSTRIAL USE
- As a component of animal feed, providing a relatively cheap source of fixed nitrogen to promote growth.
- As a raw material for the manufacture of plastics specifically, urea-formaldehyde resin.
- As a raw material for the manufacture of various glues (urea-formaldehyde or urea-melamine-formaldehyde). The latter is waterproof and is used for marine plywood.
- As an alternative to rock salt in the deicing of roadways and runways. It does not promote metal corrosion to the extent that salt does.
- As an additive ingredient in cigarettes, designed to enhance flavour.
- Sometimes used as a browning agent in factory-produced pretzels.
- As an ingredient in some hair conditioners, facial cleansers, bath oils and lotions.
- It is also used as a reactant in some ready-to-use cold compresses for first-aid use, due to the endohermic reaction it creates when mixed with water.
- Active ingredient for diesel engine exhaust treatment AdBlue and some other SCR systems.
- Used, along with salts, as a cloud seeding agent to expedite the condensation of water in clouds, producing precipitation.
- The ability of urea to form clathrates (also called “loose compounds” host-guest complexes, inclusion compounds, and adducts) was used in the past to separate paraffins.
- As a flame-proofing agent.
- As a clean burning fuel for motor vehicles and stationary engines.
- As a NOx-reducing reactant in diesel exhaust.