Peat is an important component of plant substrates and is used primarily in horticulture to improve soil quality. However, its extraction destroys valuable moorland areas and releases carbon that has been stored there for thousands of years. Researchers at the Leibniz Institute for Agricultural Engineering and Bioeconomy (ATB) have now developed an environmentally friendly alternative and have applied for patents for two innovative processes for producing artificial peat.

Artificial peat from biomass

In nature, peat is formed by the decomposition of dead plant remains in moors due to a lack of oxygen and moisture. What nature takes a thousand years to achieve, the ATB researchers led by Nader Marzban have managed in just 30 minutes – without harming the environment or climate. ‘We can produce artificial peat from almost any organic source material, including biomass such as wood, grasses, leaves and paludiculture plants,’ explains the inventor of artificial peat, Nader Marzban. ‘This process requires water, pressure and temperatures between 70 and 120 °C, as well as a suitable formula for successful production.’

Marzban came up with the idea after a mishap while cooking, when ingredients burned in a pressure cooker and left black-brown residues on the bottom. For the researcher, the mishap prompted the question of whether this burnt mass could also have humus-like properties. Laboratory analyses confirmed his suspicion. Further experiments with agricultural residues followed and were equally successful. Together with Thomas Hoffmann and Ralf Pecenka, Marzban further developed the approach until two processes for producing artificial peat were created.

Simple and scalable process

In the first process, artificial peat is produced in two steps using alkali-assisted twin-screw extrusion. Here, the biomass is first cooked under pressure at around 70 °C. The fibres of the material are then broken down in the twin-screw extruder. The result is ‘a stable, humus-rich material whose properties can be adjusted to match or even exceed those of natural peat,’ according to the report. The peat substitute produced in this way is particularly suitable for applications in agriculture and horticulture, where fibrous materials and humic substances are required.
The second method produces artificial peat from biomass in a single step using a batch process. It is particularly suitable for less fibrous raw materials, but requires a slightly higher temperature of 120 °C.

Climate-positive and reusable

The artificial peat is not only free of pathogens, but also contributes to carbon sequestration, making it climate-positive. After use, the substrate can be recycled and reprocessed. The ATB team is convinced of the potential of artificial peat production: ‘It offers a way to replace natural peat, reduce emissions and recycle biomass.’ Due to its scalability and low cost, industrial production will soon be possible. Furthermore, the concept is an ‘exciting starting point for continuous development, adaptation and innovation,’ according to Marzban.

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