A research group from Karlstad University have found that biochar, one of the bioproducts from the paper industry, can be used as an effective fertiliser.
Biochar is a carbon-based substance similar to charcoal and is made by burning organic material in a controlled process called pyrolysis.
“Biochar has many beneficial effects on the environment. Our lab experiments show that by enriching biochar we can produce a very effective fertiliser for forest plants. If we bring biochar back to the forest, it will remain stable for a long time.
“In this way, carbon is bound up and there is less carbon dioxide in the atmosphere, which counteracts global warming.” says Maria Sandberg, senior lecturer in environment and energy systems and research leader for the project.
The chemistry of biochar
When trees are felled for pulp and paper production, nutrients and base cations are gathered in sludge and ash. A small segment of carbon accumulates in the waste from the purification plant, which purifies the process wastewater.
Researchers successfully transformed the waste sludge into biochar in order to create a new type of soil conditioner which can be used to grow more paper. When this biochar is returned to the forest it can reduce soil acidification and carbon dioxide emissions.
Sandberg continued: “We have conducted a pilot project with lab studies in 2018, and last autumn, Vinnova notified us that we were granted around SEK 2,000,000 to the project, which now moves into the next phase.
“The companies involved invest the same amount, bringing the budget up till around SEK 4,000,000. The participation of the Forest Agency also means that we can carry out research in forest soil, which is fairly unique in the world, and in March we will cultivate new plants of fir and pine trees.”
The research project started in 2018 and is a partnership between Karlstad University, Stora Enso, Paper Province, Karlstad municipality, Econova, Mellanskog, Forest Agency and Umeå Energy. The project, which will end in 2022, is funded by Vinnova and the participating partners.
Biochar’s growing popularity
Biochar has recently gained a lot of attention from the agriculture industry as a viable alternative to fertilisers. According to a recent report by Market Watch ‘A key variable in the performance of biochar producers is raw material costs, specifically the speed at which any increase can be passed through to customers.
‘The materials of biochar include wood, rice stove, corn stove and other biomass materials. Wood now is the major raw material of biochar, but its price would be higher than other derived product. The price of crop raw material fluctuates with agricultural market in local market’.
The global biochar market is expected to grow substantially in the future, owing partially to the increased demand for organic food, which is also anticipated to be a prime driver for the global biochar market over the forecast time period. Positive government policies, cheaper raw materials, and rising environmental awareness for waste management are further likely to play a major role in driving the global biochar market.