Biogas and digestate are two products of the methanization process: after the degradation of the materials, on the one hand the biogas that has escaped is recovered, and on the other the digestate which is the solid residue of the materials. These last two have different uses and interests.

Biogas is a renewable energy source

This gas mixture, mainly composed of methane (CH4) and carbon dioxide (CO2), can:

• to be used as fuel in a boiler to produce heat;
• powering an engine to produce electricity and heat at the same time: this is called cogeneration;
• serve as fuel for vehicles: this is called bio Natural Gas Vehicle (bioNGV);
• be purified and injected into the natural gas network: we then speak of biomethane.

Biogas is sometimes used directly by farmers to dry hay or heat a greenhouse, and by communities to heat public buildings and run fleets of buses running on bioNGV. Less noisy, these buses are also significantly less polluting: they emit almost no fine particles and generate 80% less CO2.

Digestate is used to feed crops

As for it, digestate is used as a fertilizer to feed agricultural crops, or as an amendment for soil balance. In addition to reducing the use of synthetic fertilizers, it is an excellent quality fertilizer that is easily assimilated by plants.