Dall Energy
Thermal oxidizer
Particle removal in condensator
Cooling & DH

Cooling & DH

In biomass plants with high efficiency are there two types of gas coolers:

  1. a high temperature cooler which cool the flue gas from app 950 C to app 150c
  2. a low temperature condensating cooler which cool the gas to 30-40C

Approximately 2/3 of the energy is recovered in the high temperature cooler and 1/3 of the energy is recovered in the low temperature cooler.




Dall Energy have developed a concept, where the flue gas is cooled by a high temperature quench. Hereby is the investment and maintenance costs of the boiler reduced.

The plants in Sønderborg and at Warwick Mills was a first step to demonstrate the concept. Here a compact boiler is cooling the flue gas to app 400C before the quench.


Dall Energy biomass system with small high temperature cooler and quench that cooles from 400C to 100C.


Such system has been built  in biomass plants in Denmark and in the USA during 2014.




Boiler free biomass plant 

The ultimative solution is a boiler free biomass plant. Here are the investment- and maintenance costs of the boiler eliminated. Such project is being prepared in Holte, Denmark.

Principle layout of the "Boiler free biomass plant" in Holte.

Air moisturizers


Air moisturizers are used to warm up and moisturize the combustion  air and to cool the condendate.
The use of air moisturizers have several advantages:

  • Increased energy efficiency in the condensator
  • Reduction of NOx and slagging in the Furnace


System layout with high temperature quench, recirkulation of particles to furnace and airmoisturizers