Decarbonizing the Industrial Sector Through Natural Refrigerant Heat Pumps

As pressure builds to decarbonize every sector of industry, transitioning from gas fired furnaces and boilers to natural refrigerant heat pumps is a proven way to cut emissions and realize utility savings. The introduction of a Carbon Tax and the rising cost of fossil fuel gases further supports this transition, making industrial natural heat pumps an attractive investment.

The federal Canadian Net-Zero Emissions Accountability Act of 2021 requires a 50 percent emissions reduction by 2030. This means that the industry is fast running out of time to drastically transform its operations to meet this target. Fuel switching from fossil fuel to hydrogen is not the answer. The infrastructure required and the resulting operating costs can be exorbitant. Switching to natural refrigerant heat pumps is more cost-effective and cuts emissions significantly, as seen by a growing number of successful installations around the country (and the world).

"The large-scale natural refrigerant heat pump market is poised for remarkable growth, driven by the eco-friendly attributes of carbon dioxide and ammonia as a refrigerant, increasing demand in commercial establishments, and proactive government initiatives to reduce carbon emissions," explained David Fauser, sales director at CIMCO.

Heat pumps are nothing new – the technology has been around in applications of all sizes for many decades. The residential heat pump market in particular has recently enjoyed a massive boom, especially in Europe where the need to accelerate decarbonization was driven by the ongoing Ukraine-Russia war and subsequent rising fossil fuel costs. Now, as larger heat pump components become more readily available, at ever-reducing costs, these systems are also gaining popularity in the industrial sector.

Unlike gas-fired furnaces, boilers, and hot water heaters that create less than one unit of heat from one unit of energy, heat pumps are designed to capture and upgrade several units of heat from a source, such as the environment, with only one unit of energy. This effectively increases the coefficient of performance (COP) of the system to 4 – sometimes as high as 10, depending on the application and refrigerant used.

This improvement in efficiency leads to much lower energy use – saving on indirect emissions (from electricity use) and thus monthly utility bills. This can make the life cycle cost of a heat pump lower than that of a traditional heating system, even if heat pump systems may have a higher upfront cost. Especially when calculating the cost of Carbon Tax plus the expected jump in natural gas prices.

When it comes to direct emissions, it is important to make the distinction between natural gas (which is a type of fossil gas that release significant amounts of CO₂ and other emissions when burned) versus natural refrigerants (which are circulated in a closed system and even if a leak occurs, have negligible or no direct CO₂ emissions and are considered environmentally friendly). Natural refrigerants include hydrocarbons, CO₂, and ammonia.

For industrial and process applications, ammonia (R717) refrigerant has been used for well over 100 years – since 1850. Ammonia refrigerant has a global warming potential (GWP) of 0, which means it is considered to have no harmful effect on the environment. The availability of industrial refrigeration compressors suitable for providing higher heating temperatures now enables natural refrigerant heat pumps to deliver high-quality hot water up to 190°F (88°C) with research and development ongoing to push this even higher.

Repurposing waste heat further reduces fossil fuel use and related emissions.

Heat pumps charged with fluorinated refrigerants or f-gases (like HFCs, HFC/HFO blends, or HFOs) on the other hand, do not have a negligible GWP, most have impacts that are hundreds to thousands of times that of CO₂. Plus, f-gases are subject to ongoing refrigerant phase-downs around the world, increasing the risk of being forced to take out these systems prematurely to comply with regulations. With industrial heat pump installations expected to last in excess of 20 years (potentially even 40 years or more), making a future-proof refrigerant decision is vital.

By switching from fossil gas to ammonia heat pumps for heating, the direct emissions of a heating system are automatically cut to 0 – a win for decarbonization. Plus, ammonia is regarded as the benchmark for efficiency in industrial refrigerant applications, further reducing indirect emissions from energy use. For example, when comparing an effective COP of 6 versus a boiler system with a COP of 0.8, a heat pump can provide 7.5 times more heat energy for each unit of energy input, according to industry studies.

Another key benefit of switching to an ammonia or CO₂ heat pump is the potential to capture industrial waste heat from the refrigeration process and upgrade it for use in heating processes. By integrating the heating and cooling processes of a facility, this waste heat is no longer simply vented into the atmosphere. Repurposing waste heat further reduces fossil fuel use and related emissions.

With ammonia, the heat pump function can easily be added to the industrial refrigeration system, eliminating the inefficiency of having to transfer the heat from the refrigeration system to a separate heat pump system.

A secondary yet significant benefit is that the heat pump diverts load away from evaporative condensers, allowing them to operate at lower pressures and conserving water and water treatment resources. This is another saving on the utility bill.

Proven Savings at Maple Leaf

Maple Leaf Foods in Brandon, Manitoba is a prime example of how switching to a natural refrigerant heat pump can greatly reduce electricity use, cutting down emissions and accelerating the facility’s journey to decarbonization. The plant processes 18,000 hogs per day, five days a week, and uses 140°F water for up to 22 hours a day.

Traditionally, this process relied on natural gas boilers and direct-contact water heaters. By adding a heat pump function into the existing ammonia refrigeration system, Maple Leaf reduced its natural gas consumption by 3 million cubic meters annually, amounting to savings of $223,599 (per year).