What is biomethane?
Also known as ‘green gas’, biomethane is produced from organic waste. Its properties are similar to those of natural gas, making it suitable for use as vehicle fuel and in heating applications. It also has its own specific benefits, the most important of which is its non-toxicity. ENGIE designs, produces and operates facilities at every link in the biomethane chain.
What exactly is biomethane?
Biomethane is a 100% renewable energy source produced by the natural breakdown of organic material: green waste, household waste, agricultural waste, food industry waste and even industrial waste. The process of breaking down this material in an oxygen-free environment produces biogas, which is then purified to become biomethane. This can then be used as a vehicle fuel, distributed in the mains gas supply or used to generate green power.
The advantages of biomethane
- It can help reduce greenhouse gas emissions and improve air quality. It could help France reach the 3×20 targets to which it has committed and meet the objective of an integration of 10% of fuel from renewable sources in transportation by 2020.
- Production of this renewable energy can be decentralized: biomethane is the renewable part of natural gas and can be used in exactly the same way. It is just as easy to transport as it is to use locally.
- Its use will create local employment that cannot be delocalized.
- It will contribute to the commitments of industrial players and local authorities (Agenda 21, Plans climat territoriaux,Plans énergie SRCAE).
Three different production methods
There are three generations of biomethane production, differentiated by the organic matter used and the transformation process.
- First-generation biomethane produced by decompositioncomes from the anaerobic decomposition of organic waste, which is the result of the natural breakdown of organic matter. This raw or slightly pre-treated gas is called biogas, and can be used locally to produce electricity, heat, or both in a combined-cycle process. After further purification, the biogas becomes biomethane, 100% renewable energy of the same quality as natural gas, which can be used in vehicles or injected into the natural gas network. ENGIE has developed two biomethane industrialization projects in France:
- The injection of first-generation biomethane into the natural gas network in Lille.
- The use of biomethane fuel in vehicles in Forbach.
- Second-generation biomethane is produced by gasification from ligno-cellulosic biomass (wood and straw), using a “thermochemical conversion” process. This process is carried out in two stages:
- Firstly, the biomass is converted into synthetic gas.
- This synthetic gas is then transformed into biomethane by catalytic synthesis.
ENGIE is developing this technology, and it should be available by 2017.
- Third-generation biomethane comes from the direct transformation of micro-algae cultivated in high-yield photosynthetic reactors using natural light, water and minerals, while recycling CO2. This is an emerging technology due to be developed on an industrial scale by 2020-2030.