Wood Gasification and Walter Technology
Walter produces both electricity and heat from wood chips.
In the process, dry wood chips are converted into wood gas at a high temperature. The gas is cooled and cleaned before being fed into a gas engine. The engine drives a generator that produces electricity, while the heat generated in the process is recovered as hot water.
One Walter unit produces:
- 50 kW electrical output
- 120 kW thermal output
Wood chips → wood gas → gas engine → electricity + heat
What is wood gasification?
Wood gasification is a process in which solid wood fuel is converted into combustible gas at a high temperature.
In Walter, wood chips are fed into a gasification reactor, where they are processed at a high temperature with a limited supply of oxygen. The resulting wood gas can then be used as fuel for a gas engine.
Unlike conventional wood combustion, where the energy is primarily converted directly into heat, gasification also makes it possible to generate electricity from the wood fuel.
How the process works
1. Wood chips are gasified
Dry wood chips are fed into the gasification reactor, where they are converted into wood gas at a high temperature.
The quality and moisture content of the wood chips affect the performance of the process, making proper fuel handling an important part of the system.
2. The gas is cooled
The hot gas produced during gasification is directed through a heat exchanger, where its temperature is reduced to approximately 200 °C.
At the same time, heat can be recovered as part of the energy production process.
3. The gas is cleaned
Solid particles are removed from the wood gas before it is fed into the engine.
The purpose of the cleaning stage is to ensure that the gas supplied to the gas engine is suitable for its intended use.
4. The gas is prepared for the engine
In a second heat exchanger, the gas temperature is reduced to approximately 60 °C. Air required for combustion is then mixed with the gas.
5. The generator produces electricity
The wood gas and air mixture is fed into the gas engine. The engine drives a generator that produces electricity.
Walter has an electrical output of 50 kW.
6. Heat is recovered
Heat generated by the gasification process and the gas engine is recovered as hot water.
The heat can be used, for example, for:
- heating buildings
- domestic hot water
- drying
- agricultural and industrial processes.
Walter provides 120 kW of thermal output, available for useful applications in the form of hot water.
50kW
Electrical output
120kW
Thermal output
Video of the process:
Electricity and heat from the same system
Walter operates on the CHP principle, producing electricity and heat simultaneously.
In a conventional wood chip boiler, the energy contained in the wood chips is used primarily for heat production. In Walter, the wood chips are first converted into wood gas, which is then used to generate electricity. The heat produced during the process is recovered at the same time for useful applications.
Fuel quality matters
A stable gasification process requires wood chips that are suitable for the system.
Key characteristics include:
- moisture content
- particle size
- consistency
- level of impurities.
When required, the power plant system can be complemented with solutions for wood chip drying, screening, storage and feeding.
Automatic process control
Walter’s automation system continuously monitors power plant operation and adjusts the process based on measurement data.
The operator can monitor the plant from a touchscreen without the need for continuous manual adjustment.
The automation system controls the entire process, including:
- gasification
- gas treatment
- the gas engine
- electricity and heat production.
Remote monitoring and control
Power plant operation can also be monitored remotely through Volter’s cloud service using a computer or mobile device.
Remote access makes process monitoring easier and supports maintenance, troubleshooting and overall system management.
Walter’s automation is based on an ABB programmable logic controller, and the system also supports alarms and remote control.
Technology that scales with energy demand
One Walter unit produces 50 kW of electrical output and 120 kW of thermal output.
For larger applications, multiple power plant units can be combined. More detailed information about Walter’s dimensions, fuel consumption and available delivery options can be found on the product page.
Want to learn more about the technology?
Walter combines wood chip gasification, gas treatment, a gas engine, a generator and heat recovery into an automated energy production system.
If you are planning electricity and heat production based on wood chips, we can help you assess whether Walter is suitable for your site.
Contact us to learn more.
