Energy & Green Tech

Chemists use brewery waste to manufacture carbon compounds for energy storage devices.

A crucial component of a climate-friendly future are cutting-edge energy storage systems. “Modern” refers not only to their capability of being produced and recycled sustainably but also to their performance meeting the requirements of a society based on high technology. Scientists occasionally discover unexpected raw materials in their search for new resources, such as brewery waste.

The bio-source of brewer’s spent grain has been tested by chemists at Friedrich Schiller University Jena and Spanish colleagues to produce materials for electrochemical energy storage systems. Carbon, which can be used as an electrode in batteries, was obtained, and activated carbon was used as a material for an electrode in supercapacitors. The chemists used waste from Jena’s “Papiermühle,” a hotel, restaurant, and brewery, for their experiments.

The researchers came up with a way to make carbonaceous materials that could be used for storage. They optimized the materials’ pore sizes and surface areas in the case of activated carbon. These carbons guarantee a very high capacitance when used as an electrode in supercapacitors, making it possible to create a device with a high energy density.

“If certain parameters, such as cost or raw material chemical composition, can be further tuned, this form of waste could be an appealing option for generating materials for supercapacitors.”

Prof. Andrea Balducci from the University of Jena.

Brewer’s spent grains are readily available; however, why did the team select brewery waste? Prof. Andrea Balducci from the University of Jena explains, “We have been researching the suitability of various biological raw materials for realizing carbon-containing materials that we use to create energy storage devices for some years now.”

“Also, significant requirements for this are met by brewery waste: its substance structure is on a basic level truly reasonable for the applications we’re focusing on. Additionally, brewer’s spent grains are readily available in large quantities; in 2019, the European Union produced approximately 6.8 billion tons, with 1.5 billion tons coming from Germany alone. Breweries are also spread out across the nation, making waste readily available and eliminating the need for lengthy journeys to obtain the raw materials.”

The specialists in Jena had the option to source their brewer’s spent grains for their tests from a nearby distillery.

According to Balducci, the scientific community has not paid much attention to brewery waste products despite their abundance. For instance, the majority of the activated carbon used in supercapacitors currently comes from coconut shells. Despite the need for additional research, this may alter in the future.

Balducci adds, “If certain factors, such as the cost or the chemical composition of the raw material, can be further optimized, this type of waste could be an interesting option for producing materials for supercapacitors.” We will work on additional projects to learn more about the benefits and drawbacks of using this abundant material so that it can be used more frequently to make sustainable energy storage.”

The journals Electrochimica Acta and Energy Technology have published related research.

More information: Sandesh Darlami Magar et al, Brewery waste derived activated carbon for high performance electrochemical capacitors and lithium-ion capacitors, Electrochimica Acta (2023). DOI: 10.1016/j.electacta.2023.142104

Sandesh Darlami Magar et al, Brewers’ Spent Grains‐Derived Carbon as Anode for Alkali Metal‐Ion Batteries, Energy Technology (2022). DOI: 10.1002/ente.202200379

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