Gasification of biomass
What is gasification?
Biomass gasification is a thermal process that converts organic fuel (or fossil fuel) based carbonaceous materials (wood like waste such as wood scrap, shells, pellets, etc.) into a combustible gas comprised of carbon monoxide, hydrogen and carbon dioxide. This is achieved by reacting the material at high temperatures, without combusting it, using a controlled oxygen inlet. The resulting gas mixture is called syngas.
Syngas can then be burned directly in CHP (combined heat and power) gas engines for the simultaneous production of heat and electricity.
How does it work?
Gasification systems are usually paired with a CHP system; so the syngas is being produced locally, in the same place where it used to generate green power. The heat coming from the CHP engines is also used in the syngas production process. This results in no transmission or distribution losses.
The installation consists of two main stages:
- The production of clean gas
The biomass gasification procedure is divided in 4 zones where the carbonaceous material undergoes several processes:
Here the wood scrap is dried, shredded and briquetted, and any chemically not bound water is evaporated.
The pyrolysis takes place in this zone. The wood-like fuel is converted at high temperatures to charcoal and a carbonisation gas
Tars and other distillates are gasified at dominant temperatures, and controlled amounts of preheated air are supplied in. Chemical reactions also take place to form CO2 and water vapour, the carbonisation gas is split up.
Further reactions occur and create CO, CO and H2, and CH4 (methane).
The ashes formed by the process are used as quality fertiliser
- The combustion of the syngas in a CHP engine
The CHP unit, consists of engines powered by the syngas and are coupled to an electric generator, which produces electricity. Waste heat from the motor bloc and exhaust gas is released at the same time, and is re-used in the gasification process.
Through the thermal “cracking” of waste, a mixture of mainly CO, CO2, H2, CH4, N2, H2O and hydrocarbons is formed. This “gasfraction” can be combusted for the production of electricity, potentially with cogenaration.
The produced syngas can also be used in the chemical industry or for the production of transportation fuels. Depending on the intended use, the syngas needs to be purified and contaminants such as dust and tar need to be removed.
The higher the temperatures, the higher the efficiency
Biomass gasification requires temperatures between 750°C and 1400°C. In order to obtain a maximal conversion of the organic material and to reduce the levels of tar to a minimum, temperatures need to be as high as possible. An efficiency of 30-40% can be achieved.
- Conversion of organic waste into renewable fuel
- CO2 neutral technology
- Free, quality fertiliser as by-product
- More independence from the volatile energy market
- Secure source of electricity and heat
- No transmission losses of fuel or electricity
- Reduced heat costs by using waste heat as a free energy source
Upgrade Energy seizes the opportunities of bioenergy. We offer project-based solutions for electricity producers, agricultural companies and government institutions. We not only take care of the engineering and construction, but also operate and maintain bioenergy projects.
If you are interested about the opportunities of gasification for your company, please feel free to contact us!