Heat recovery systems for flue gas or exhaust air in Paper & Pulp Mills

Corrosion and fouling problems limit the recovery of more heat. With polymer heat exchangers you can recover additional heat and overcome these issues.

Improve thermal efficiency

Prevent Corrosion & Fouling

Get a Technical Assessment

Your thermal processes are losing up to 15% of their energy through the stack

What's keeping you from recovering this energy?

Availability of a robust solution

Finding a technically feasible solution to recover and reuse waste heat is a challenge.

Corrosive and fouling flue gases

When burning biogas from anaerobic waste water treatment or biomass, the flue gases are corrosive and fouling.

Business case

The payback time of waste heat recovery options must be less than 5 years.

We design and deliver heat recovery systems for Paper & Pulp Mills to reduce their carbon footprint

Save up to 10% energy on your thermal process

Recover heat - that is now lost - from flue gas or exhaust air.

Your thermal process has waste heat recovery potential

Select your thermal process to find out how

Recover more heat on dryers

Recover heat from your dryer exhaust air to preheat fresh drying air. Make your dryers up to 20% more efficient.

Recover more heat on steam boilers

Recover flue gas heat to warm up water or preheat combustion air. Make your steam boilers up to 10% more efficient.

The way our heat recovery system works

Capture waste heat

When hot flue gas and exhaust air leave the stack, they still contain a significant amount of energy. Our heat recovery system captures this heat from dryers and steam boilers.

Preheat drying air, combustion air or water

Drying air, combustion air, process water, make-up water or boiler feed water are heated with the captured waste heat. This directly reduces the consumption of fossil fuels.

Our heat recovery systems for Paper & Pulp Mills

Polymer Air Preheater

Warm up combustion air or drying air by extracting heat from flue gas or exhaust air. The air preheater is corrosion resistant, easy to maintain and to clean.

Stainless Steel or Polymer Economiser

Warm up boiler feed water, make-up water or process water with waste heat from flue gases or exhaust air. The economiser is corrosion resistant and is easy to maintain and to clean.

Case study: Paper mill Europe

6% efficiency improvement

This paper manufacturer has the ambition to make their production processes more sustainable. Their steam boiler is being co-fired with biogas. Currently, heat recovery from the flue gas of this boiler is limited due to the potentially corrosive nature of the flue gas.

Conventional metal air preheaters are not suitable for deep cooling of the flue gas because the acids in the flue gas will condense. A case study was prepared for the combination of a metal and polymer air preheater system. With this system, flue gas will be cooled down through the acid dew point to preheat the combustion air.

Combustion air will be preheated from 25 to 179 °C. The polymer air preheater part in the installed combination will make sure that there are no corrosion issues.

Your path to lower CO2 emissions, energy consumption and costs


Technical assessment

Our process engineers assess the technical feasibility of additional heat recovery on your process. The potential reduction in CO2 emissions, energy consumption and costs is determined.

Heat exchanger design and Business Case

A proposal is made that shows all technical details and an economic assessment with payback time. You have everything you need for approval to start a feasibility study.


Feasibility study

We or your preferred Engineering company can perform a feasibility study to create the budget estimate you need to get management approval for CAPEX.


On a paper mill, a number of thermal processes are in operation, such as dryers, boilers and CHP's. On boilers and CHP's, high grade heat is lost through the stack with the hot flue gas. This can be as much as 15% of the energy that is put in. By recovering the heat from the flue gas to preheat combustion or drying air, a significant reduction in energy and CO2 emission can be achieved. Alternatively, the waste heat can be used to warm up water for further use.
Sulphur in fuels like natural gas, biogas, biomass, coal or fuel oil gets combusted and forms SOx. Most of this is in the form of SO2 and 2% to 4% is present as SO3. This SO3 condenses when flue gas is cooled and forms sulphuric acid (H2SO4). This leads to corrosion of metal surfaces, ducts and stacks. This condensation reaction takes place when the flue gas temperature drops below, or the flue gas comes in contact with a surface temperature below what is called the Acid Dew Point. The polymer heat exchange technology allows flue gas to be cooled without having the risk of corrosion.

Making your boiler or CHP more efficient reduces fuel consumption and therefore lowers fuel costs. In addition, by making the heat recovery resistant for corrosion enables you to use biogas, which will further increase your savings. Clients have improved their efficiency by 5 to 10% and achieved payback times on the project investment in the range of 3 to 5 years.

Technical Assessment of your situation

Our process engineers assess technical feasibility of additional heat recovery on your process. The potential reduction in CO2 emissions, energy consumption and costs are determined.