Sustainable methanization project at Prestia SBG

Efforts for starting the methanization process

Before Prestia SBG, could start with this project, they conducted with their partners, 12 local farmers, a 5-year study following an investment of €2,500,000. In 2015, the construction of the biogas unit started and in October 2016 the commissioning of the installation took place. For this, Prestia SBG provided the hot water to heat the digestates (39°) and thus started the biological process.

Advantages of the project

The methanization has many advantages for the environment. One example is that the waste of the crops and livestock can be recovered. There has also been a great reduction in the purchase of chemical fertilizers by farmers. Until now, the methanization had an annual production of 2.080.820 electric kWh, which is equivalent to the consumption of 500 households excluding heating. This production is sold to EDF. Additionally, 866.910 thermal kWh is produced, which is sold to Prestia SBG. Prestia SBG can use this for the heating of their pre-treatment baths.

The installation also helps with the recovery of digestate because it replaces mineral fertilizers. This has led to a reduction of purchases by 80% in 2022, objective is to reach 100% in 2023.

Investment in the methanization

In 2022, there was an investment made for a second 250kW motor-generator and a larger capacity heat exchanger. This means the thermal energy consumption limit increases from 866,910 thermal kWh to 1.8 M kWh, which means that more than 80% of the site's hot water needs and almost 20% of the total energy needs will come from this installation! The company BIOGAZ-IA, specialized in biogas units and Artificial Intelligence, will also contribute on an optimization. This company will analyze the Prestia SBG production data to better anticipate and adjust the parameters of the methanization according to these data.

Before the methanation process, the heating of the pre-treatment baths was executed exclusively with propane gas. Now, the recovery of thermal energy on the Prestia site makes it possible to reduce the environmental footprint by 233 tonnes CO2 per year. And with the two engines, the objective is to decrease this footprint by 500 tonnes CO2 per year!