Beer and biogas: the advantages for a brewery

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Beer and biogas: the advantages for a brewery

How Much Energy Is Needed to Produce 1 Hl of Beer?

Beer is one of the most appreciated alcoholic beverages among consumers, but its production process is extremely energy-intensive. According to Assobirra‘s 2023 annual report, in Italy, 7 kWh are required to produce one hectoliter of beer. Considering that in 2023, 17.43 million hectoliters were produced in the Country, it is necessary to integrate technologies to make the industry more sustainable. One concrete and immediately actionable example could be the energetic valorization of by-products. These by-products are, in fact, a valuable resource and can be utilized for biogas production. The following paragraphs will describe the by-products, the optimal anaerobic digestion technologies for their valorization, and the benefits for a brewery that chooses the path of sustainability.

Trebbie birra biogas

By-products to be Utilized for Biogas Production:

Brewers’ Spent Grains:

Brewers’ spent grains are the solid residue left after the wort extraction process and constitute the majority of the by-products from the brewing process. It is estimated that their production goes from 14 to 20 kg/hL of beer, depending on factors such as the recipe, the type of malt used, or the efficiency of the process. They are characterized by their residual content of proteins, aminoacids, sugars, and fats, making them suitable biomass for anaerobic digestion and biogas production.

Spent Yeast:

Although it’s an essential ingredient in the beer fermentation process, a significant amount of spent yeast remains in the fermenter at the end of the process; on average, about 1 kg of spent yeast is produced per 1 hL of beer. However, being very rich of organic substances, it is an excellent biomass for feeding a biogas plant.

Wastewater:

The brewing process requires very high quantities of water, approximately 400 L/hL of beer. Wastewater also results from the use of water for washing equipment, cleaning barrels, and cleaning facilities. Their valorization in anaerobic digestion is possible as they are rich in organic matter, sugars, proteins, and other nutrients.

Anaerobic Digestion Technologies for Breweries

Spent grains, yeast, and wastewater are three optimal biomasses for feeding a biogas plant. Depending on the type and quantity of biomass available to the brewery, SEBIGAS recommends the most suitable reactor, choosing between the CSTR and anMBBR. For solid biomasses, the CSTR reactor is preferred, as it is a flexible solution suitable for the anaerobic digestion of heterogeneous and complex biomasses, ensuring stability in biogas production. The biogas production from spent grains and yeast is estimated to be around 110 Nm³/t of fresh biomass. In the case of highly liquid effluents, the anMBBR reactor is preferred, as it is a suitable solution for on-site management of high stream volumes in reduced digestion volumes.

anMBBR technologyCSTR technology

Which are the advantages for a brewery?

Valorizing the by-products from the brewing process offers significant advantages for a brewery, both environmentally and economically.

  • Reduction in disposal costs and taxes: by managing by-products, breweries can lower the costs and taxes associated with their disposal.
  • Production of renewable energy: the energy generated from biogas can be used for self-consumption, thereby reducing the economic impact of energy procurement.
  • Creation of a new revenue stream: if the electricity produced from biogas is fed into the national grid, it can create an additional income source.
  • Reduction of environmental impact: implementing sustainable production processes can significantly lessen the brewery’s environmental footprint.

At SEBIGAS, we can support your company through an ecological transition, turning waste into opportunities. If you’d like to learn about our case studies and discover how much energy your brewery can produce, please contact us at sales@sebigas.com or fill out the form.