Energy Recovery & Decarbonising
Healthcare

Hospital with chimney on top emitting white steam into the atmosphere

Decarbonising our Healthcare Service

At Macleod SV, we are pioneering the use of supercritical carbon dioxide (sCO2) energy recovery and vapour compression systems in the mission to achieve a Net Zero healthcare service. sCO2 is able to work at a very wide temperature range which makes it excellent for use with heat recovery, heating and as a heat engine.

Supercritical carbon dioxide (sCO2) energy recovery is used to extract and separate specific compounds or substances from a mixture by utilising sCO2 as an alternative to the refrigerants used in heating and cooling systems. Supercritical CO2 refers to a state where carbon dioxide is maintained at a temperature and pressure above its critical point. In this state, CO2 exhibits both liquid and gas-like properties, making it an excellent alternative to refrigerant.

Key advantages of using sCO2 in energy recovery processes include:

  1. Safety
    Supercritical CO2 is non-toxic, and non-flammable, making it a safer alternative to traditional refrigerants, particularly for use in healthcare and pharmaceutical applications.
  2. Environmental impact:
    The use of supercritical CO2 reduces the need for harmful chemical refrigerants, making it an environmentally friendly option.

When water is replaced by sCO2 as the working fluid in the Rankine Cycle, things start to get interesting.

What is an Organic Rankine Cycle (ORC)?

A Rankine Cycle is a thermodynamic cycle that converts thermal energy into electric energy. The heat is supplied to a closed loop, typically using water as the working fluid.

When sCO2 replaces water as the working fluid in a Rankine Cycle, it becomes an Organic Rankine Cycle (ORC). In this configuration, sCO2 is used to capture waste heat and convert it into useful energy:

  1. Waste Heat Source:
    The sCO2 recovery system captures waste heat from a process, such as from flue gas or other high-temperature sources.
  2. Supercritical CO2 Recovery:
    Waste heat enters the recovery system where heat is absorbed and the sCO2 expands, driving a turbine to produce mechanical energy. This process is an incredibly efficient method of heat recovery.
  3. Organic Rankine Cycle (ORC):
    The ORC system uses the sCO2 to generate electricity by expanding it through an expander, much like a traditional Rankine cycle.

The advantage of using sCO2 in the ORC system is that it can operate at higher efficiency and at a broader range of temperatures compared to traditional ORC fluids like organic hydrocarbons. Additionally, sCO2 has a lower critical point, allowing for more compact equipment designs.

Want to find out how sCO2 could help you achieve NetZero?

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Organic Rankine Cycle

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