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Park and garden waste

How park and garden waste are dealt with today

Each year, approximately 450,000 tonnes of park and garden waste are generated in Sweden’s municipalities. Additionally, there is also a considerable amount of park and garden waste being produced by cemetery administrations and other private actors. Handling all the material in an effective way is challenging from a management standpoint, because it involves such large quantities and the material in question is heterogeneous. Some of it is composted, while the rest is incinerated. However, the latter often leads to issues with the incineration plant as the high levels of sand and nutrients in the park and garden waste cause significant wear on the equipment.

Why make biochar out of park and garden waste?

As of now, a significant proportion of the park and garden waste cannot be recycled as it contains too high levels of various contaminants, including heavy metals such as cadmium and lead. Several heavy metals, one of which is cadmium, are separated out when park and garden waste is converted into biochar using pyrolysis. Phosphorus and other nutrients can therefore be reintroduced without the heavy metals.

WHAT WE DO IN THE PROJECT REST TILL BÄST

In the municipalities of Lund and Trelleborg, the park administrations use a sorting method called the Lund model. This means that the park waste is sorted into both a finer fraction suitable for composting and a coarser wood chip fraction that is well suited for fuel at the site where it is produced. Within the framework of Rest till Bäst, we will be conducting tests involving the pyrolysis of the wood chip fraction. Garden waste is also added to the compost, and from there we sort out wood as a raw material for producing biochar. Furthermore, we will evaluate which pre-treatment methods, such as crushing, chipping, sifting and drying, are most suitable. As with other organic residues, we will also explore how the pyrolysis process can be optimised, especially with regard to temperature.

COMMITTED PROJECT PARTNERS

CONTACT

Markus Paulsson
markus.paulsson@lund.se
+46 (0) 46-359 53 36
City of Lund, City Office
221 00 Lund, Sweden

REST TILL BÄST

Rest till Bäst is a Vinnova-funded project whose purpose is to develop solutions for managing society’s organic residues and create a much needed beneficial product, while at the same time minimising environmental and climate impact.