Ammonia heat pumps are at the center of many key initiatives to reduce the environmental impact of industrial applications while ensuring top efficiencies are achieved.
As the focus in the industry is increasingly in reducing greenhouse gas emissions and putting sustainability to the front, ammonia refrigeration is emerging as a key solution.
Paired with cutting-edge industrial heat pumps, this approach is capable of upcycling and reusing heat, bringing down heating costs and minimizing the use of fossil fuels.
As a consequence, diverse industries are benefiting from the implementation of ammonia heat pumps with the aim of recovering energy from waste heat: from food and beverage processing plants, to chemical manufacturing or the paper industry, among others.
Through specialized thermal engineering expertise, it’s possible to harness the true potential of this technology, accessing the economic and environmental benefits of reusing waste heat.
What is an Ammonia Heat Pump?
An Ammonia Heat Pump is a piece of equipment that is capable of transferring heat from a lower temperature source to a higher temperature sink using ammonia as a refrigerant.
There are several reasons why ammonia represents an advantageous refrigerant choice:
- It presents excellent thermodynamic properties that make it highly efficient
- Its efficiency means it can shorten paybacks, provided the right system is designed
- Has zero global warming potential
- Can be employed for high-scale applications and produce high temperatures
- Has a long lifespan
Ammonia heat pumps are emerging as key solutions for decarbonizing the industry today thanks to their capacity to reclaim heat from low-grade heat sources and upgrade it to a higher temperature that is suitable for industrial processes. As such, some key sources of low temperature heat used include sea water, ground water, or waste heat from industries, thermal plants or data centers.
Publicly available data about ammonia heat pumps showcases 40% reductions in energy consumption and 40% lower costs compared to synthetic refrigerants.
Additionally, ammonia heat pumps can be designed for providing both heating and cooling, which can offer additional savings.
How Ammonia Heat Pumps work in industrial settings
Ammonia heat pumps can prove outstandingly useful and provide important investment paybacks in industries where combined cooling and heating are needed, as well as industries where waste heat is significant.
Additionally, they’re demonstrating value in accelerating decarbonization efforts in industries looking to minimize their emissions, all while accommodating the requirements needed for large-scale project capacities.
The thermodynamic cycle of ammonia heat pumps
The core of the thermodynamic cycle of ammonia heat pumps includes the following processes: evaporation, compression, condensation, and expansion. These operations guarantee the system is able to recover low-grade heat and upcycling it to use it in industrial processes:
- Evaporation: low temperature heat is extracted from the source, so that low-grade heat is captured.
- Compression: ammonia in the form of gas is compressed, increasing its pressure and temperature
- Condensation: the high-temperature, high-pressure ammonia gas enters a heat exchanger, where it releases heat into water as it is condensed back into a liquid. The heated water is circulated through piping so that it can fulfill its intended industrial use.
- Expansion: the ammonia liquid passes through expansion valves to reduce its pressure and temperature. Now converted into cooled ammonia, it can re-enter the cycle.
Waste heat recovery in industrial processes
Heat pumps can be designed to incorporate waste heat as the source for low-temperature heat. As such, this process is able to reuse heat that would otherwise be lost during industrial processes, including that produced by exhaust gases, discharged water from cooling systems or heat from manufacturing processes.
Waste heat recovery in industrial processes allows for significant energy efficiency improvements, while also reducing energy costs. Considering the volume of wasted heat across some industries, ammonia heat pumps stand out as a key solution by creating closed-loop systems where heat is constantly recycled and reintegrated into productive operations.
Additionally, the possibility to reuse heat as part of district heating systems is also emerging as a key solution.
Advantages and challenges of Ammonia Heat Pumps in industrial applications
Benefits of using Ammonia Heat Pumps
The choice of ammonia as a refrigerant presents a series of advantages compared to synthetic refrigerants:
- Highly efficient natural refrigerant
- Great sustainability and is exempt from potential F-gas regulations in the future. As such, ammonia presents a zero GWP (Global Warming Potential) and zero ODP (Ozone Depletion Potential) = 0. As such
- More economical than synthetic alternatives, including the total lifetime cost
- High volumetric capacity
- Long lasting
These advantages add up to the benefits of heat pumps per se, which include a high energy efficiency and the capacity to upgrade waste heat, as well as the potential integration of renewable energies.
Challenges and considerations when implementing Ammonia Heat Pumps
The handling of ammonia must take into account a series of security measures, considering its toxicity, flammability, and potential health hazards in case of leaks or improper containment.
As such, design for systems incorporating ammonia heat pumps should ensure proper ventilation, the use of personal protective equipment (PPE), and adherence to safety protocols.
Adequate design considerations also involve the choice of technologies within ammonia heat pumps to match each project’s needs. For instance, compression technologies should be selected according to the expected conditions when the heat pump is integrated in the system.
Additionally, the IEA points out the production of ammonia today still largely relies on fossil fuels. However, the organization also emphasizes “encouraging progress on near-zero-emission technologies is being made”, including “electrolysis, methane pyrolysis and fossil-based routes with carbon capture and storage (CCS).”
Harnessing energy from waste heat in industrial applications
As seen above, ammonia heat pumps represent a crucial step forward in devising sustainable, circular heating systems for industrial applications.
At the center of this development is advanced heat pump technology, which has been estimated to have the potential to “reduce global carbon dioxide (CO2) emissions by at least 500 million tonnes in 2030 – equal to the annual CO2 emissions of all cars in Europe today” according to IEA figures.
As more and more efforts are dedicated to devising sustainable, emission-free processes for the industries, waste heat recovery technologies are expected to thrive thanks to their capacity to promote environmentally-friendly systems. As such, an analysis by Research and Markets predicts the global waste heat recovery system will reach USD 102.41 billion by 2030, with a CAGR of 9.8% from 2024 to 2030.
The analysis also mentions how industries such as refineries, heavy metals, paper & pulp, petrochemicals and chemicals are predicted to invest in waste recovery technologies as a measure to reduce their operational costs and environmental impact.
These transformations are expected to be amplified by supportive policies as well as increasing regulations regarding emissions.
Successful heat pump implementations regarding waste heat are gaining traction across diverse sectors. Such is the case of data centers that repurpose their waste heat to be used in district heating.
When it comes to industrial processes, successful waste heat recovery schemes are also emerging across the globe, from innovative food and beverage processing factories to automotive manufacturers, all working to achieve carbon-neutral factories and processes.
A webinar by the European Heat Pump Association showcased how one of Germany’s largest paper processing facilities has managed to reduce their natural gas consumption “down by 453,000 cubic metres” and their annual CO₂ emissions by 231 tonnes.
The association also highlights a case of “industrial-urban simbiosis” in Spain “where waste heat from a district heating network was upgraded via high-temperature heat pumps to produce steam for a metal processing plant.” According to their sources, the project achieved savings of “13,000 megawatts of thermal energy annually and reduced CO₂ emissions by 1,200 tonnes.”
In the meantime, research continues in order to make ammonia heat pumps increasingly efficient. Such is the case of ammonia-water mixtures, which are being explored for their capacity to increase efficiency as part of the thermal exchange process.
When it comes to integrating ammonia heat pumps in industrial applications and waste heat recovery, ARANER offers the expertise and attention to detail needed to guarantee project success.
Only through careful system design is it possible to maximize efficiency and access the benefits outlined above. As such, we offer tailor-made solutions that consider the right type of equipment for each project and integrate them within existing capabilities.
Want to learn more? Discover our district heating solutions and industrial heat pumps and get in touch with us and speak to our team about how we can help you.
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