Methanization is a complex biological process that involves several stages and interactions between different microbial communities, to ensure the proper digestion and degradation of biowaste.

In this article we give you an overview of these steps as well as examples of products that are used to optimize the reactions and therefore increase the efficiency of the plant (i.e. the rapid and efficient production of methane).

At the beginning of the process, complex organic molecules are broken down into simple molecules through the action of enzymes: this is called hydrolysis. These enzymes break the bonds between molecules, thus facilitating the digestion of organic substrates.

To speed up hydrolysis, it is possible to add enzymes to the digester, which can be in liquid form (like MethaZyme ) or powder form (like MiaMethan ProCut ).

During acidogenesis, the products of hydrolysis are transformed into volatile fatty acids (such as acetate, propionate or butyrate). Acidogenic bacteria are responsible for this step.

These volatile fatty acids will then be converted into acetate, carbon dioxide and hydrogen by acetogenic bacteria: this is acetogenesis.

The next step of methanogenesis is to reduce these last three molecules into two: methane and carbon dioxide. The addition of trace elements can optimize these steps to ensure a rapid reduction of volatile fatty acids thanks to chelated resins that capture excess acids and gradually release them into the digester – this is the purpose of MiaMethan SOS for example.

It is after methanogenesis that methane can be recovered and used as a renewable energy source (heat, electricity, green gas, biofuel, etc.). This biogas may still contain impurities such as hydrogen sulfide, carbon dioxide or volatile organic compounds.

There are two types of products to reduce these impurities: products to prevent their appearance during the process, and products to eliminate them at the end.

To prevent the formation of hydrogen sulfide in the digester, ferrous products such as iron hydroxide ( Sorb Neo ) or iron chloride ( Kronofloc ) are used.

To purify biogas once produced, activated carbons are very effective: they are porous products that will absorb these compounds. There are many varieties of activated carbons that adapt to the needs, depending on the proportions of hydrogen sulfide or volatile organic compounds to be eliminated. Methappro offers a complete range of 5 activated carbons depending on the treatments to be planned: treatment of hydrogen sulfide , treatment of volatile organic compounds or mixed treatment .

pH and temperature are crucial factors that will affect the efficiency of reactions. These are two data that must be particularly monitored, and that must be prepared to regulate if necessary.

The pH should be between 6.5 and 7.5 to create the ideal environment for methanogenic bacteria. In case of acidosis (accumulation of volatile fatty acids leading to a significant drop in pH), calcium carbonate can be used to raise the pH, such as this product: Vitacarb .

Methappro has listed for you the best products to optimize each step in your methanizer. For any additional information or quote request, contact us:louis@methappro.fr