Considering heat recovery can lead to substantial savings in both new and existing plants when planning new utility investments. It can cut both future operating costs, utility systems and capital investment costs.

Recovering process heat reduces investment costs in systems for heat generation and cooling, as well as costs for space.

Boilers and burners

Recovering heat leads to a lower need for new heat, reducing the capacity need of boilers, direct fired heaters and furnaces.

Cooling

The first thing to consider when planning new cooling capacity is how to reduce the input of heat into the system. Recovering heat reduces the cooling need and a cooling tower of less capacity will suffice.

10 MW of recovered heat can lead to 300,000 EUR reduced cooling tower cost, assuming:                                                       

• A new plant is under construction or cooling tower capacity has to be expanded
• The inlet-outlet delta T is 8°C meaning the cooling water flow is reduced by approximately 1000 m³/h
• The calculations are based on average values calculated from models presented in Petroleum refining – Technology & economics 5th edition(Gary, Handwerk, Kaiser ) and Chemical Process Design and engineering (Smith)

10 MW of recovered heat can lead to 500,000 EUR reduced steam boiler cost, assuming:

• A new plant is under construction or steam boiler capacity has to be expanded
• Cost estimation according to models published in Chemical Process Design and engineering (Smith)
• Installation factor 3
• Boiler pressure 6 bar(a)  

Waste heat recovery often reduces the load on the utility systems.