Nitrogen Fertilizer Production Process

Just like most living creatures, plants have basic needs in order to thrive: water, food and protection from diseases and pests. Commercially produced fertilizers give plants the nutrients needed for health and growth.

Nitrogen typically accounts for approximately 60% of worldwide fertilizer consumption in any planting season. It is an essential element for most organic compounds in plants, as it promotes protein formation and is a major component of chlorophyll, which helps to promote green healthy growth and high yields.

The production of virtually all nitrogen-based fertilizers starts with the production of ammonia. There are a number of processes that produce the various fertilizers derived from ammonia, the most common of which include: urea, ammonium nitrate, urea ammonium nitrate solution, and ammoniated phosphates (often referred to as MAP and DAP). The diversity of products facilitates site-specific agricultural applications, which take into account factors such as soil type and the requirements of the crop, thus making it possible to achieve optimal plant nutrition.

Ammonia is the basic building block for producing nearly all forms of nitrogen-based fertilizers. To a lesser extent, it is also used directly as a commercial fertilizer. Ammonia is produced by reacting gaseous nitrogen with hydrogen at high pressure and temperature in the presence of a catalyst. Nearly all hydrogen produced for the manufacture of nitrogen-based fertilizers is produced by reforming natural gas at a high temperature and pressure in the presence of water and a catalyst. Hydrogen can also be produced by gasifying petroleum coke. This process, which is commercially employed our nitrogen fertilizer plant and a few other plants, takes advantage of the large cost differential between petroleum coke and natural gas in current markets. Because of the wide availability of feedstocks capable of being reformed into hydrogen, ammonia and nitrogen fertilizers are produced in many countries.

The Four Principal Nitrogen-based Fertilizer Products

Ammonia: Ammonia is used in limited quantities as a direct application fertilizer, and is primarily used as a building block for other nitrogen products, including intermediate products for industrial applications and finished fertilizer products. Ammonia, consisting of 82% nitrogen, is stored either as a refrigerated liquid at minus 27 degrees, or under pressure if not refrigerated. Although it is gaseous at ambient temperatures, it is injected into the soil as a liquid where it is rapidly absorbed. The direct application of ammonia requires farmers to make a considerable investment in pressurized storage tanks and injection machinery, and can only take place under a narrow range of ambient conditions.

Urea: Urea is formed by reacting ammonia with carbon dioxide (CO2) at high pressure. From the warm urea liquid produced in the first, wet stage of the process, the finished product is mostly produced as a granular solid containing 46% nitrogen and suitable for use in bulk fertilizer blends containing the other two principal fertilizer nutrients, phosphate and potash.

Ammonium Nitrate: Ammonium nitrate is another dry, granular form of nitrogen based fertilizer. It is produced by converting ammonia to nitric acid in the presence of a platinum catalyst reaction, then further reacting the nitric acid with additional volumes of ammonia to form ammonium nitrate liquid, which is granulated as a solid containing 35% nitrogen.

Urea Ammonia Nitrate Solution (UAN): Urea solution can be combined with ammonium nitrate solution to make liquid nitrogen fertilizer (urea ammonium nitrate or UAN). These solutions contain 32% nitrogen and are easy to store, transport and provide the farmer with the most flexibility in tailoring fertilizer, pesticide and fungicide applications.