How Wood Gasification Boilers Work

In general, the process of gasification uses high heat and low oxygen to turn carbon-based fuel into energy. This process differs from standard combustion because it uses far less oxygen, and it relies on a series of stages to make the process happen.

The key to this process is the combination of a controlled amount of oxygen, intense heat, and adequate combustion time. At the end of the reaction between the fuel and the oxygen, the resulting hot gasses are used for heating by transfer to water, which is distributed to the building. While wood gasification in most wood boilers is not true gasification with extremely low oxygen, the process utilizes all of the key gasification concepts.

Gasification takes place in Froling wood boilers with automated primary and secondary controls, which react in real-time to oxygen and temperature in the exhaust. Gasification is easy to understand when it's looked at in three steps. The stages are as follows:

1. Drying phase: In this initial stage, the wood begins to burn and produce smoke in the primary chamber.  As the wood dries, smoke is heavily laden with steam. The smoke is driven into the secondary combustion chamber, injected with hot air, and smoke burnout begins.  During this phase, it is common to see a white exhaust plume on cold days.  That is water vapor.
2. Smoke production/volatilization phase: As the wood dries in the primary chamber, more volatile gasses are released.  These volatile gasses now available in high quantities, continue to burn in an extremely hot secondary combustion.  Wood in the primary chamber begins to convert to charcoal.  During this phase, there is no visible smoke.
3. Charcoal phase:  Volatile gasses diminish in quantity and the remaining charcoal is slowly burned away.  There is no visible smoke during this phase and particulate emissions are very low.

Some of the advantages of wood gasification boilers include:

• Low-cost fuel: Biomass Wood is readily available and local.  Firewood is processed from trees that are diseased, dying, or crooked.  Because firewood can be harvested in our own backyards and purchased from our neighbors, the fuel can offer a huge price advantage over other fuels.
  
• Carbon neutrality: When wood is harvested no faster than it grows, it is a carbon-neutral fuel. If you're looking to reduce your carbon footprint with the most efficient and low-impact wood utilization possible, wood gasification is a great option.
  
• Efficiency: Higher efficiency means less wood handling, less cleaning, and lower emissions.

At Tarm Biomass, we carry gasification boilers from Fröling, a leading manufacturer in the industry. Take a closer look at the S3 Turbo and why it might be a smart move for your home or business. The Tarm Biomass team is here to help you find the best boiler system for your space. To learn more, get in touch with our team today.