Abundance of trace elements in demonstration biogas plants

► Abundance of trace elements at 10 demonstration biogas plants representing different technologies and different feedstocks across Europe established. ► Results compared with recent findings in literature. ► Feedstock used influences the availability of micro nutrients in digesters. ► Abundance of trace elements is improved by a large variety in feedstock whereas feeding with manure and energy crops may lead to a depletion of micro nutrients over a long time span. ► Need for further research into the successful application of trace elements in biogas plants