Flue Gas Condensation & Heat Recovery
Maximize boiler efficiency by recovering waste heat from flue gases using Thermax absorption heat pumps combined with SEGFlu scrubber technology. Reduce chimney temperatures from 150°C+ down to 15-25°C while capturing condensation energy for district heating networks.
Transform Waste Into Valuable Energy
Flue gas condensation is one of the most effective methods to increase overall boiler plant efficiency. By cooling exhaust gases below their dew point, we recover the latent heat of condensation — energy that would otherwise escape through the chimney.
Thermax absorption heat pumps, deployed in partnership with our Danish distributor SEG Energy and their proprietary SEGFlu flue gas scrubbers, provide a proven solution for this application across Scandinavia and Central Europe.
The system works by circulating cold water from the heat pump’s evaporator through the flue gas scrubber, cooling exhaust gases to near-ambient temperatures. The recovered energy preheats district heating return water, dramatically improving overall plant efficiency.
System Flow & Energy Recovery
A closed-loop system that extracts maximum energy from boiler exhaust while preheating district heating water.
Boiler Exhaust
Hot flue gases exit boiler at 150-180°C containing significant waste heat
Flue Gas Scrubber
SEGFlu scrubber cools gases with chilled water from heat pump evaporator
Condensation
Flue gas cooled to 15-25°C, recovering latent heat of water vapor condensation
District Heating
Recovered heat preheats return water from 45°C to 70-85°C before boiler
Why Flue Gas Condensation?
Efficiency Increase
Boost overall plant efficiency by 10-20% by capturing waste heat that would otherwise be lost through the chimney stack.
Fuel Savings
Significant reduction in fuel consumption as recovered heat reduces boiler firing requirements — rapid payback typically under 5 years.
Carbon Reduction
Lower emissions by reducing fuel burn — critical for meeting climate targets and regulatory requirements.
Continuous Operation
Designed for 8,000+ hours per year operation with minimal maintenance — proven reliability in demanding district heating applications.
Water Recovery
Condensed water from flue gases can be treated and returned to the boiler feedwater system, reducing makeup water requirements.
Proven Technology
Multiple successful installations across Denmark, Sweden, and Germany demonstrate reliable long-term performance.
Scandinavian Case Studies
Real-world installations across Denmark and Sweden demonstrating exceptional performance in district heating applications.
Amager Bakke ARC
Northern Europe’s largest waste-to-energy plant features eight Thermax absorption heat pumps recovering heat from flue gas condensation.
Lemvig Kraftvarmeværk
Biomass-fired district heating plant achieving exceptional flue gas cooling to 18°C chimney temperature.
Vestervig Fjernvarme
Small biomass district heating plant demonstrating technology scalability with record-low chimney temperature.
Egedal Fjernvarme
Municipal waste-to-energy plant with integrated flue gas heat recovery for district heating network.
Uppsala Kraftvarme
Major CHP installation with four absorption heat pumps recovering flue gas heat for Sweden’s fourth-largest city.
Eksjö Energi
Biomass-fired district heating plant demonstrating effective flue gas condensation in Swedish climate conditions.
Technical Specifications
| Parameter | Typical Range | Notes |
|---|---|---|
| Flue Gas Inlet Temperature | 150-180°C | Standard boiler exhaust temperature |
| Flue Gas Outlet Temperature | 15-25°C | Below dew point for maximum condensation |
| District Heating Return | 40-50°C | Typical return from distribution network |
| District Heating Supply | 70-85°C | After heat pump upgrade |
| Heat Pump Capacity | 300kW – 40MW | Scalable for various plant sizes |
| Efficiency Gain | +10% to +20% | Overall plant efficiency improvement |
| Payback Period | 3-5 years | Depends on fuel costs and operating hours |
| Operating Hours | 8,000+ hrs/year | Continuous district heating operation |
Maximize Your Boiler Efficiency
Our engineering team will evaluate your flue gas temperatures and district heating requirements to design an optimized heat recovery solution.
Request Efficiency Analysis