"Wunderwuzzi biochar" - how it can help save the climate
Our Scientific Advisory Board member Andreas Jäger is a big proponent of the use of biochar in the fight against global warming. We need to reduce the number of greenhouse gases in the air to limit global warming to 1.5 degrees. On the one hand, technical processes, which are only in their infancy today, and on the other hand, natural methods are used. This includes the use of biochar. This is made from biomass. Biochar stores CO2 in the long term, which was previously taken from the air. There are some exciting applications for biochar, which we will also take a closer look at.
Saving the climate through photosynthesis and pyrolysis
Plants removeCO2 from the air and split it into oxygenO2 and carbon C by means of photosynthesis. They use this to build up their biomass. To preventCO2 from escaping back into the atmosphere, it is retained in the plants by pyrolysis (charring). Charring is a centuries-old principle that was used both in South America in tropical areas for the production of "terra preta" and in our latitudes for the production of charcoal. For this purpose, organic material such as wood, plant residues and waste from food production is thermally treated at high temperatures without oxygen. As a result, the biomass carbonizes and the carbon remains bound in it – unlike during combustion or rotting, where it is released again.
The process initially requires an energy supply, but also has a temperature range in which energy is released. This excess heat from larger systems can be fed into a district heating network.
Depending on the raw material and process control, gases, pyrolysis oil and a solid residual product such as biochar are produced. These gases must be collected in order to be environmentally friendly and can be used as "biogas".
Special properties of biochar
Sponge structure
Biochar has very special properties: its porous structure makes it an excellent reservoir for microorganisms, water and nutrients. Their surface is like a sponge. This allows it to absorb more than three times its weight in water.
Soil improvement
Biochar as a soil conditioner, known as terra preta, has been known since ancient cultures in the Amazon. "With terra preta, the remains of the charred materials were the key to making the otherwise quite infertile soil fertile again in the long term," Gerhard Soja, who researches biochar at the AIT Austrian Institute of Technology and the University of Natural Resources and Life Sciences, Vienna, told DerStandard. "Biochar is more beneficial to soils that are degraded or less able to retain nutrients," says Dominic Woolf from Cornell University in the US.
Each gram of biochar has a surface area of around 300m2! So you have to be careful: Applying biochar directly to the soil can lead to negative effects, as the charcoal must first be "charged" with nutrients and microbiology. Only when the charcoal is saturated can it develop its positive effect. For this reason, biochar should always be used together with organic fertilizer. The indigenous people of Brazil, for example, mixed it with dung.
Gigantic CO2 storage
Its greatest benefit in the fight against the climate crisis is its millennia of carbon storage: "What makes biochar relevant, not least for climate protection, is its ability to store CO2 for many millennia. If biochar were to be used globally, it is estimated that two gigatons of CO2 per year could be permanently stored, says Maria-Elena Vorrath, a geoscientist at the University of Hamburg. For comparison, according to the Global Carbon Project, all of humanity emitted around 38 gigatons of CO2 in 2022.
"Biochar," writes the IPCC, "could make a significant contribution to both mitigating land degradation and climate change. both soil degradation and climatechange." In technical jargon, this is called pyrogenic carbon capture and storage (PyCCS). "Alongside humus formation and reforestation, biochar is the key negative emissions technology, as it can be implemented on a gigatonne scale in the short term and offers valuable co-benefits," says Daniel Kray, who researches photovoltaics and biochar at Offenburg University and biochar at Offenburg University of Applied Sciences. It would be even more effective to also store the oil that is produced during pyrolysis. For example, in old oil reservoirs: "That would be safe and ecologically sensible, but expensive." Better: use and store the oil, for example mixed into asphalt.
Areas of application
Kathleen Draper researches the various ways in which biochar can be used. She is the US director of the Ithaka Institute, an international network for carbon strategies, and co-author of the book Burn: Using Fire to Cool the Earth (2019). In a video interview with GoodImpact, she holds a gray brick in her hand and explains: "This is made of recycled plastic and biochar. I made it with my students in The Gambia. Applications like this are great, especially for countries where there are no established plastic recycling systems." She points next to her: "This wall contains around 500 grams of biochar, but also materials such as recycled glass." Outside, she says, there is a septic tank with biochar - as a purifying filter medium. "Solutions like this make so much sense." Draper has been researching biochar for years and says: "The journey is just beginning."
Andreas Jäger presents the use of biochar for concrete in his blog. By adding it, climate-damaging concrete becomes climate-neutral. The vision is for concrete to become aCO2 sink.
One of the most important areas of application for biochar is humus formation, which is essential for binding carbon, and there is an Austrian initiative humusplus, which deals intensively with this topic and also offers further training and much more on the subject. A symposium on the subject will be held on February 5 and 6.
You can find the information here!
Austria is home to the world's only pyrolysis plant
Andreas Jäger visited this plant in Pinkafeld, which was designed by Gerald and Dominik Dunst. This is the first biochar production plant in Europe to be approved under waste legislation and has been in continuous operation since July 2012. It produces 1,500 kg of high-quality biochar every day. Overall, the industry is becoming more professional worldwide and the number of pyrolysis plants is increasing. In Germany, there will be a separate funding line for humus formation and the use of biochar in 2022.
Sources:
Mirror: How biochar is supposed to save the climate
DerStandard: Cool coal: How biochar can contribute to climate protection a
