How waste heat recovery can cut costs

6 days ago
3 min read

Industrial processes generate a lot of heat. Much of this heat is often lost to the environment. But what if we could capture that heat and put it to good use? Recovering waste heat is a smart way to save energy, reduce costs, and lower carbon emissions. This approach is especially important with the recent energy cost increase.

Why waste heat recovery matters

Process manufacturing industries like food, beverages or chemicals use a lot of energy. They often produce heat as a byproduct. This heat usually escapes through exhaust gases, cooling water, or hot surfaces. When that heat is lost, it means more fuel or electricity is needed to keep operations running.

Recovering waste heat can:

Lower energy bills by reusing heat instead of burning more fuel.
Reduce carbon emissions by cutting fuel consumption.
Support sustainability goals and comply with environmental regulations.

When energy costs are high and power supply can be unstable, capturing waste heat is a practical way to improve business resilience and competitiveness.

How waste heat recovery works in practice

Waste heat recovery involves capturing heat from industrial processes and using it for other purposes. This can be done in several ways:

Heat exchangers transfer heat from hot gases or liquids to cooler fluids.
Heat pumps upgrade low-temperature heat to higher temperatures.
Thermal storage holds recovered heat for later use.
Heat transfer fluids carry heat from one location to another.

The key is to match the heat source with a useful application. For example, recovered heat can be used for:

Preheating boiler feedwater or combustion air.
Heating buildings or process fluids.
Generating steam or hot water.
Powering absorption chillers for cooling.

Each application reduces the need for fresh energy input.

Eye-level view of industrial heat exchanger system in a factory — Eye-level view of the piping in a factory

Products that help capture and use waste heat

Choosing the right equipment is crucial for effective waste heat recovery. Here are two products that can help South African industries make the most of their waste heat:

1. Heat exchanger units

Heat exchangers are devices that transfer heat between two fluids without mixing them. They come in various designs, such as shell-and-tube, plate, and spiral types. A good heat exchanger can recover heat from exhaust gases or hot liquids and transfer it to water or thermal oil.

For example, a company might install a heat exchanger to capture heat from furnace exhaust. The recovered heat can then preheat water for steam generation, reducing fuel use.

2. Thermal Oil Heat Transfer Systems

Thermal oil systems use special heat transfer fluids that can operate at high temperatures without high pressure. These systems can move heat from the source to distant points in the plant safely and efficiently.

Thermal oil systems are ideal when the heat source and heat use points are far apart. They also allow precise temperature control, which is important for sensitive processes.

How to start recovering waste heat

Implementing waste heat recovery requires planning and analysis. Here are some steps to get started:

Identify heat sources: Look for hot exhaust gases, cooling water, or heated surfaces.
Measure temperatures and flow rates: Understand how much heat is available.
Find heat sinks: Determine where recovered heat can be used.
Select equipment: Choose heat exchangers or thermal oil systems that fit your needs.
Calculate savings: Estimate energy and cost reductions.
Plan installation: Consider space, safety, and maintenance.
Monitor performance: Track energy savings and system health.