Trinidad’s Urea Industry

Urea is a white crystalline substance with chemical formula CO(NH₂)₂. It is highly water soluble and has about 46% nitrogen. It is produced from combining ammonia (NH₃) and carbon dioxide (CO₂).

There are two urea plants located on the Point Lisas Industrial Estate: one at the facility of PCS Nitrogen Trinidad Ltd and the other Methanol Holdings Trinidad Limited Ammonia Urea Ammonium Nitrate Melamine Plant (A-U-M complex).

Table 1: Urea Plants in Trinidad

The urea production process is briefly described in the flow chart below:

The process starts with ammonia and carbon dioxide being fed to the synthesis reactor. The ammonia-stripping urea process involves high ammonia [NH₃] to carbon dioxide [CO₂] ratio in the reactor, ensuring the high conversion of carbamate to urea. The ammonia and carbon dioxide are fed into the reactor at high temperature and pressure, and the urea is formed in a two-step reaction:

2NH₃ + CO₂NH₂COONH₄ (ammonium carbamate)

NH₂COONH₄H₂O + NH₂CONH₂ (urea)

The urea solution is then concentrated and granulated for use as a fertilizer and chemical feedstock for export. Granular urea is generally larger than prilled urea, with both having the same composition. The larger granular size provides greater granular strength and minimum fines, dust and powder and losses in the air. With the majority of the urea produced by PCS Nitrogen Trinidad Ltd being exported, these superior qualities of the granular urea are ideal.  Urea formaldehyde (which acts as an anti-caking agent) is then added to the urea melt to restrict the tendency of the urea granules to absorb moisture. The granular urea is then sent to the bulk warehouse where it is stored under controlled temperature and humidity.

Please refer to the link below for a more detailed description of the urea process from PCS Nitrogen: http://www.potashcorp.com/media/pdf/about/PCS_Trinidad_Fact_Sheet.pdf

Urea must be handled with care at all times. A typical MSDS for urea can be found at the link given below:

http://www.jtbaker.com/msds/englishhtml/u4725.htm