How Industries Use Ammonia for Refrigeration

Ammonia for Refrigeration

Many are aware of ammonia’s widespread use as a powerful fertilizer in the agricultural industry to dispel nitrogen into the soil to foster successful plant growth一which makes sense, seeing as around 80 percent of all ammonia is used in this fashion.

But industrial ammonia has a wide scope of uses in manufacturing, agriculture, and more. One use of this chemical is as an industrial refrigerant. 

In fact, ammonia was one of the earliest refrigerants used in mechanical systems. These refrigeration systems first appeared in the 1800s and their mechanisms have changed very little since the early 1900s. Ammonia was first synthesized in 1823 by reacting air and hydrogen, and commercial production of the chemical stretches back as far as 1913, and was quickly used in these refrigeration systems. 

While manufacturers produce 18 million metric tons of ammonia each year in North America, somewhere around 2 percent is used for refrigeration purposes. 

But all of this is slowly changing. 

While ammonia may have temporarily taken a backseat to other chemical refrigerants used in mechanical refrigeration systems, it’s now experiencing a resurgence of use thanks to its price, effectiveness, and environmentally friendly properties. 

Ammonia as a Refrigerant

All refrigeration systems use the same principles of physics to move heat energy from one area to another to create a cooler environment. While not all refrigeration systems use ammonia, the same basic ideas are the same, whether it’s the family refrigerator in the kitchen, indoor ice hockey rinks, or massive food processing plants. 

For quite some time, ammonia has been widely used as a refrigerant in a variety of refrigeration solutions, but it is most commonly used in vapor-compression refrigeration systems

Because ammonia has an incredibly low boiling point, it is ideal for this kind of refrigeration. When used as a refrigerant in vapor-compression refrigeration systems, the liquid ammonia moves around, circulating through multiple stages where it is alternately compressed and expanded. When the vapor is compressed, it becomes a liquid, and when it expands, it vaporizes again. As this vaporization occurs, the ammonia absorbs the surrounding heat energy, and as it condenses, it releases this heat to its new location.

Ammonia is used in other kinds of refrigeration systems, including:

  • Thermal expansion valve systems
  • Flooded systems
  • Liquid recirculation systems

Why Ammonia Makes for a Reliable Refrigerant

Since it was first used in the practice of the vapor-compression refrigeration cycle, ammonia has remained the most common refrigerant used in industrial refrigeration systems. This is the result of a few undeniable perks:

  • Ammonia has superior thermodynamic properties, meaning it absorbs large amounts of heat as it evaporates. 
  • Ammonia is an affordable refrigerant, making it much more cost-effective to use in large quantities for industrial uses.
  • Ammonia is more eco-friendly than many alternatives if and when it’s released into the atmosphere. It does not contribute to ozone depletion or global warming.

Just how much more effective is ammonia compared to other refrigerants? Manufacturing.net shared statistics from the International Institute of Ammonia Refrigeration (IIAR) stating that ammonia is between 3 to 10 percent more thermodynamically efficient than other refrigerants, which means it offers better cooling with less power, providing lower operating costs in the long run.

While generally, industrial ammonia is considered benign to the environment, other refrigerants like chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), and other synthetic refrigerants, which are not as gentle on our fragile ecosystem. 

Ammonia requires careful storage and transport protocols, but it is much safer than other synthetic refrigerants. Although it burns within a narrow range of high concentrations, it’s not quick to ignite and does not support combustion. It also breaks down quickly in the environment, which helps to minimize its environmental impact. 

Plus, because ammonia has a very distinctive odor, the use of ammonia as a refrigerant makes it easy to detect spills, leaks, or other accidental releases and fix them before they cause a major issue. Most people can detect incredibly low concentrations of ammonia in the air一as low as 20 parts per million (ppm), making leaks easy to detect and repair before they can do any kind of real harm. 

Industries That Rely on Ammonia for Refrigeration

Ammonia refrigeration has been the workhorse of refrigeration and cold storage since the early 1900s, even though it was used as early as the 1850s for ice production. Since it’s so cost-effective and energy-efficient, ammonia refrigeration is used for the processing and storing of both frozen and unfrozen foods. It’s used for:

  • The post-harvest cooling of produce
  • The cooling of meat, poultry, and fish
  • The refrigeration of all kinds of beverages
  • The refrigeration of milk and cheese
  • The freezing of ice cream and other frozen foods
  • The creation of beers and wines 
  • The production of many food products throughout the manufacturing process

Essentially, all fruits, vegetables, meats, and beverages pass through at least one facility that relies on ammonia refrigeration systems before going home to consumer (and commercial) kitchens.

Ammonia is still used as a refrigerant in large-scale cooling systems for locations like ice rinks, but more recently, ammonia is used to provide air conditioning in locations like college campuses, office parks, smaller buildings like convenience stores and small businesses, and larger office buildings. Especially in Europe, environmental regulations have encouraged engineers to come up with new ammonia refrigeration systems that provide safe, cool air conditioning in places like hospitals, public buildings, airports, and hotels.

Ammonia refrigeration systems are also used to provide cooling for the International Space Station and Biosphere II and are even used at power generation facilities to maintain safe, comfortable operating conditions. It’s also used in:

  • Seafood processing sites aboard ships
  • Petrochemical facilities
  • Supermarket refrigeration systems
  • Other large-scale air conditioners

Airgas Specialty Products: Your Preferred Industrial Ammonia Partner

At Airgas Specialty Products, we work across a vast array of industries, supplying industrial ammonia for use in agriculture, manufacturing, and as a refrigerant. 

Ammonia requires careful storage and transportation, and our team of engineers is well-equipped to supply our clients with industrial ammonia as well as safety training, ongoing maintenance checks, field service, repairs, development and supply of storage and delivery systems, and safe transportation of ammonia. 

To learn more about how Airgas Speciality Products can support the safe usage of industrial anhydrous and aqueous ammonia, contact our team today