Unlike natural gas, which is extracted from the ground, green gas is man-made. It is obtained by purifying obtained from the transformation of organic matter by bacteria.

Green gas is therefore a renewable, sustainable energy that can be used in exactly the same way as natural gas. Still little exploited in Belgium, it is much more widely used in Germany, Austria and the Netherlands.

How is green gas produced?

To understand where green gas comes from, we need to understand biomethanation. When anaerobic bacteria (which live without oxygen) consume and digest organic matter, they produce:

• a residue called digestate;
• biogas, consisting mainly of methane.

On the basis of this totally natural phenomenon (it can be observed at the bottom of ponds, in rice fields and even in the stomachs of ruminants!), equipment has been developed to create the conditions for biomethanation.

These systems can be used to recover waste from farms, the food industry or sewage treatment plants:

• the digestate can be used as a fertiliser;
• after being treated to remove carbon dioxide, sulphur and moisture, the biogas becomes biomethane. It can be used as a green gas or fuel (CNG), or transformed into heat and electricity with the help of a cogeneration unit.

What are the differences between green gas and natural gas?

Apart from the method of production, there is no great difference between green gas and natural gas. Green gas can be used exactly like natural gas, without any modifications to your appliances or gas system.
In terms of safety, green gas is as safe as natural gas. As is the case with natural gas, a characteristic odour is added to it so that any leaks can be detected.

How can I buy green gas?

The green gas sector is still in its infancy in Belgium and no energy supplier is currently offering a "green gas" contract in the same way as you can buy green electricity.

In France and the Netherlands, some suppliers already offer their customers 100% or partial green gas packages. It is therefore likely that green gas will arrive at some point in Belgium.

For the time being, there is one filling station in our country that runs entirely on biomethane.

What is the potential for green gas in Belgium?

One study conducted by gas.be (French article), the association of Belgian natural gas transmission and distribution operators, estimates that around 10% of current natural gas consumption in Belgium could be supplied by green gas.

In order to fully exploit this potential, investment in the network would be necessary, but the current gas distribution network could already accommodate 2/3 of this biogas production.

A circular economy

Currently, biomethane remains approximately four times more expensive to produce than natural gas (French article). However, its advocates stress that it is not only the energy produced that must be taken into account, but all of its positive effects:

• reduction in greenhouse gases;
• production of non-variable and storable energy;
• development of an ecological transition approach in the agricultural world;
• local job creation;
• contribution to the achievement of climate objectives;
• etc.

They are therefore calling for political support to finance the sector. One of the proposed approaches is the introduction of a carbon tax on fossil fuels.