Waste cardboard can be used as an effective biomass fuel for large-scale power generation that could act as one more option for the UK’s renewable energy sector, reports Bioenergy Insight.
Researchers from the University of Nottingham have carried out the first detailed assessment of cardboard as a fuel source and developed a new way to analyse its composition. The study, published in the journal Biomass and Bioenergy, provides a practical method to assess different grades of cardboard for use in energy production.
The findings show that cardboard has clear physical and chemical differences compared with traditional biomass fuels. These include lower carbon levels, lower energy output during combustion, and a high presence of calcium carbonate, especially in printed cardboard.
Calcium carbonate is added during manufacturing to improve strength and appearance. However, when cardboard is burned, it turns into ash, which can affect boiler efficiency and overall performance.
To address this issue, the researchers created a new testing technique that accurately measures the calcium carbonate content in cardboard. This method allows energy producers to better judge fuel quality and suitability for large-scale use.
Biomass is currently the UK’s second-largest source of renewable electricity, generating 31.1 terawatt-hours of power in 2022. Around 8.3 million tonnes of biomass are used each year in large power plants, mainly from wood pellets and wood chips. Other biomass sources account for only a small share.
Most of the UK’s wood pellet supply is imported, mainly from the United States and Canada, highlighting the need to identify more local sources to improve energy security.
In 2021, the UK produced an estimated 5.4 million tonnes of paper and cardboard packaging waste, making cardboard a widely available but largely untapped resource.
Cardboard can usually be recycled several times but its fibres become shorter and weaker with each cycle. Once recycling is no longer possible, it is often composted or burned along with other waste.
The study suggests that instead of being treated only as waste, used cardboard could play a useful role as a steady and locally available biomass fuel.
Dr Orla Williams from the University of Nottingham said the research confirms that cardboard can be used in large power systems. She said the new testing method makes it possible to clearly understand the makeup of different types of cardboard and how well they perform as fuel. According to her, using cardboard could help create a reliable local supply of biomass and support the energy sector’s long-term sustainability goals.
