How agricultural residues are dealt with today: A waste of heating resources!
The agricultural sector creates a number of organic residues, including straw and seed and grain crop residues. In total, this amounts to about 1.5 million tonnes each year, corresponding to 6 TWh. Today, this material is composted, left to decompose directly on arable land, or incinerated for the purpose of producing bioenergy.
Why make biochar from agricultural residues?
Agricultural residues contain all the plant nutrients that the crops have absorbed. If we return them to the agricultural land, the cycles of nutrients can be closed and the need for fertilisers reduced. This is particularly relevant with regard to phosphorus, as the availability of phosphorus is limited today. In the conversion of organic residues to biochar, a high proportion of the nutrients, including phosphorus, is retained, while at the same time achieving energy recovery and creating a carbon sink.