€420,000/Year in Energy Savings: A Biomass Plant Heat Recovery Project in Poland

During an energy audit at a biomass district heating facility in Łódź, central Poland, the auditors noted something that should have been obvious but hadn't been acted on: the biomass boiler flue gas was leaving the stack at 310–340°C, while 80 metres away the facility's pellet production building was consuming purchased natural gas steam to maintain drying temperatures. The boiler exhaust was carrying roughly 3.2 MW of recoverable thermal energy at current operating conditions. The steam demand in the adjacent dryer building was running at 2.4–3.1 MW on a continuous basis. The facility was simultaneously wasting and buying the same energy. Lozzar Process was contracted to close that loop.

Lozzar Process designed a natural circulation HRSG (waste heat boiler) and installed it in the flue gas duct between the existing electrostatic precipitator and the induced draft fan — a location that required no modifications to the existing boiler or its primary combustion controls. Key specifications: — Effective heat transfer area: 620 m² — Flue gas inlet temperature: 310–340°C (design point 320°C) — Flue gas outlet temperature: 165°C (above dew point to prevent corrosion) — Steam output: 3,200 kg/h saturated steam at 8 bar(g) — Thermal output at design: 2.8 MW — Pressure vessel design: EN 13445, CE marked — Material: Carbon steel tubes, 316L stainless steel tube sheet in high-temperature zone The steam is distributed via a 95-metre insulated steam main to the dryer building, where it replaces the previously purchased gas-fired steam. An automatic bypass damper on the flue gas duct allows the HRSG to be taken offline for maintenance without interrupting boiler operation.

The HRSG was commissioned in November 2025. Performance data from the first twelve months shows: — Average thermal output: 2.8 MW (matching design) — Annual operating hours: 7,200 h/year (planned maintenance downtime: 3.3%) — Purchased natural gas steam displaced: 78% — Annual energy cost saving: €420,000 (at Q1 2026 Polish gas tariffs) — Total installed cost: €760,000 (supply, transport from Istanbul, civil works, commissioning) — Simple payback period: 21.5 months The flue gas outlet temperature of 165°C has remained above the acid dew point throughout operation — no corrosion has been observed in the downstream ductwork or draft fan, confirming the thermal margin built into the design. For biomass plant operators evaluating similar heat recovery opportunities, the lesson from this project is simple: start with your own energy audit and identify where heat is being wasted before buying anything. The economics often become compelling once the numbers are on paper.