Chemicals

Anhydrous ammonia (NH3) is one of the most important and high-volume basic chemicals produced globally. It is an essential building block and reagent for a massive array of chemicals and industrial processes.1

While the majority of industrially produced ammonia (around 80%) is used to make fertilizers (like urea and ammonium nitrate), the remaining percentage is critical to the broader chemical industry.

Here are the primary ways anhydrous ammonia is used in the chemical industry:

1. Precursor for Nitrogen-Containing Chemicals

Ammonia serves as the primary source of the nitrogen atom (N) for synthesizing nearly all inorganic and organic nitrogen-containing compounds.

• Nitric Acid (HNO3): This is one of the largest non-fertilizer uses. Ammonia is catalytically oxidized in the Ostwald process to produce nitric acid, which is used to make:
  
  

• Ammonium Nitrate (NH4NO3): Used in fertilizers and explosives.
  
  

• Polyurethanes and Dyes: Key intermediates for polymers and pigments.

• Urea (CONH2)2): While primarily a fertilizer, urea is also a major industrial chemical used to produce:

• Urea-Formaldehyde Resins: Used in adhesives, coatings, and wood products (plywood, particleboard).

• Melamine: Used to make highly durable plastic dinnerware and laminates.

• Hydrogen Cyanide (HCN): Produced by reacting ammonia with methane (the Andrussow process). HCN is an essential precursor for acrylic plastics and synthetic fibers.

• Amines and Amides: Used in a wide variety of specialty chemicals, pharmaceuticals, and detergents.

2. Manufacturing Synthetic Fibers and Plastics

Ammonia is indispensable in the production of key polymers.

• Nylon Fibers: Ammonia is used in the synthesis of Caprolactam, the monomer needed to produce Nylon 6. It is used to adjust pH and neutralize acids during the complex reaction process.
  
  

• Acrylic Fibers: Ammonia is a crucial reactant in the production of Acrylonitrile, which is the main ingredient for acrylic fibers (used in clothing) and various synthetic resins.
  
  

3. Neutralizing Agent and pH Control

As a strong base, ammonia is widely used to neutralize acidic process streams and control the pH of reaction environments.

• Acid Neutralization: Ammonia is added to acidic wastewater or process streams to neutralize them before discharge or further treatment.
  
  

• Fermentation: In large-scale industrial fermentation (e.g., in pharmaceuticals or biotech), ammonia solutions are used to maintain the optimal pH required for microorganisms to thrive and produce the desired product. It also provides a necessary nitrogen source for microbial growth.
  
  

4. Metallurgical Processes

In metallurgy, anhydrous ammonia is often "cracked" (decomposed) at high temperatures to produce a gas mixture:

• Dissociated Ammonia: This mixture, consisting of approximately 75% Hydrogen (H2) and 25% Nitrogen (N2), is a powerful, non-oxidizing, and reducing atmosphere.
  
  

• Applications: It is used in the heat treatment of metals, such as bright annealing (to prevent surface oxidation) and nitriding or carburizing (case-hardening the surface of steel).

5. Industrial Refrigeration (R-717)

Ammonia is a highly efficient and cost-effective refrigerant (R-717) used extensively in large-scale industrial cooling systems, particularly in:

• Food Processing: Breweries, meat packing, and dairy plants.
  
  

• Cold Storage: Large warehouses and distribution centers.
  
  

It is favored for its high energy efficiency and its Zero Ozone Depletion Potential (ODP) and Zero Global Warming Potential (GWP), making it a very environmentally sound refrigerant choice despite its toxicity.