As one of the key nutrients required for plant growth, nitrogen is essential to life on Earth. It plays a critical role in crop production and ultimately, producing food for the Earth’s inhabitants, particularly as the world looks to feed an exponentially growing population.
One study looked at the effects of omitting nitrogen fertilizer on cereal yields in the US and estimated that without nitrogen, average yields for corn declined by an astounding 41%, rice by 37%, barley by 19%, and wheat by 16%.
In a 2016 report examining the shifting North American nitrogen market, Fertecon noted that the US, one of the world’s largest importers of nitrogen fertilizers, has shifted to become one of the most attractive locales for nitrogen investments, largely a result of the shale boom.
How the Shale Gas Boom has Impacted Nitrogen
Natural gas is a primary component in the production of nitrogen-based fertilizers. Despite an oversupply in the current market, the recent shale gas glut has nitrogen fertilizer producers looking to take advantage of the resulting reduced production costs.
In a recent Wall Street Journal article, Rajiv Biswas, Asia-Pacific chief economist at IHS Global Insight commented on the situation: “Low-cost shale gas in the US has transformed the competitiveness of a number of industries for which energy accounts for a high share of input costs,” said Biswas. “One of the biggest winners has been the US chemicals industry.”
Two nitrogen fertilizers in particular look promising for US producers: urea and ammonium sulfate.
Urea, an organic compound created by combining carbon dioxide with ammonia at high pressures, is the world’s primary supply of nitrogen for fertilizer.
The US has seen the expansion of old urea plants, as well as the development of new ones as of late; at the end of 2015, CF Industries, a global supplier of nitrogen fertilizers, started up the first new urea plant in North America since 1998.
The Wall Street Journal states that new production facilities allowed for a 10% increase in urea output last year, all while the world’s top fertilizer producer – China, experienced a downturn as a result of the increased cost for coal, which they must first convert to gas in order to use in fertilizer production.
Increased domestic production has resulted in a major decline of urea imports; PotashCorp expects urea imports to drop 23% in 2017, after 2016 already saw an 11% decrease. They also noted that UAN imports are expected to drop more than 46% over the coming year.
Urea Granule Production
Urea granules have traditionally been produced either by a prilling tower, or a rotary spherodizer.
In prilling towers, a urea hot melt is dropped and solidifies as it falls against a countercurrent air flow. In the rotary spherodizer, which is a combination granulator and counter-current cooler,
a hot urea melt is sprayed onto a bed of recycled material in the granulation section of the rotating drum. This causes the granule to form in layers, similar to an onion. The granulated material moves to the cooling section of the drum where the granules are solidified with chilled air. The granules are screened with the oversize going to a crusher, the product going to storage, and the undersize material going back into the process with the crushed oversize as recycle.
In addition to these approaches, many manufacturers have moved to fluid bed granulation as a finishing method over the aforementioned methods. In this approach, the material is sprayed into a vessel, where air flows through the bed, causing granules to form and solidify.
It’s worth noting that urea is also frequently coated during production, due to its hygroscopic nature. Coating, carried out in a coating drum, helps to prevent moisture from reaching the urea, allowing product integrity to be maintained.
Ammonium sulfate [(NH4)2SO4], long the nitrogen fertilizer of choice, is less common now, but it is a valuable option when an area requires both sulfur and nitrogen.
The enactment of the Acid Rain Program under the Clean Air Act in the 1990s forced fossil fuel-burning power plants to extract sulfur dioxide (SO2) and nitrogen oxides (NOx) from exhaust gas before it could be emitted into the atmosphere.
While this was effective in reducing harmful emissions, what no one counted on, was that crops were inadvertently being provided sulfur through the acid rain, resulting in the need to add sulfur to many soils.
Grand View Research released an analysis last year that slated the global ammonium sulfate market for significant growth over the the next seven years, largely as a result of its applications in the agriculture industry.
In addition to renewed interest in Ammonium Sulfate, the industry is starting to see NPKS blends – traditional NPK blends that incorporate sulfur in the formulation.
Similarly, major fertilizer industry players have even started adding sulfur to Mono-Ammonium Phosphates (MAP) and Di-Ammonium Phosphates (DAP) to create customized nutrient solutions for areas where sulfur is lacking.
Ammonium Sulfate Production
A variety of methods can be used to produce ammonium sulfate. It is frequently manufactured by reacting sulfuric acid with ammonia in a pipe reactor mounted inside a rotary granulator. The hot melt from the pipe reactor is discharged onto a bed of recycled material in the granulator to grow the granule. After granulation, the material is dried in a rotary dryer, cooled in rotary cooler, and finally, screened before going to product storage.
Ammonium sulfate is also commonly produced as a by-product of other industrial processes such as at power plants, and in the production of caprolactam or nickel. FEECO has provided equipment and systems to companies in these industries to transform their wastes and by-products into a marketable fertilizer product.
In some cases, depending on the characteristics of the material and the desired specifications of the end product, alternative methods of agglomeration/granulation may be desirable, such as pelletizing on a disc pelletizer.
Nitrogen is a key component to sustaining life on Earth for all living beings. It is especially crucial to the agriculture industry in efforts to feed a growing world population.
As a result of the shale gas revolution, the US is seeing increased domestic production of urea. Similarly, the ammonium sulfate market looks set for growth as a result of its ability to provide both nitrogen and sulfur.
FEECO has been a leader in custom fertilizer production equipment and complete process systems since 1951. We provide rotary spherodizers for the production of urea, as well as pipe reactors, rotary granulators, rotary dryers, rotary coolers, and disc pelletizers for the production of ammonium sulfate, both as a virgin product and as a process by-product. We can also supply all of the necessary material handling equipment, including belt conveyors and bucket elevators.
In addition to our equipment, the FEECO Innovation Center offers unmatched testing services, from batch testing capabilities on a single piece of equipment, to continuous process loop pilot-scale testing. We can help you test the feasibility of an intended product, develop a process around your intended product, or help you improve the performance of an existing product.
We also offer an extensive line of aftermarket services for all of your fertilizer equipment needs. For more information on our fertilizer equipment, systems, and services, contact us today.