A small recycling centre in Huddinge municipality produces biogas using organic waste, which is unique in the Stockholm region. Despite the fact that only a few tons of biogas is produced every year, the plant brings important knowledge for future projects.
At Sofielund’s recycling centre, organic household waste is pretreated to become biogas and bio-fertilizer. Today, the installation produces between 130 000 – 225 000 Nm3 per year, depending on the supply of raw material. This is a relatively small amount for a biogas plant, but it still has a great impact, because it is the only plant in Stockholm, which produces biogas using only organic household waste. Commonly, biogas is produced from sewage sludge.
Trough digestion, organic waste can be reused in two different ways; as biogas or as bio-fertilizer. Biogas consists of methane and carbon dioxide. Biogas can be used as it is for heating or electricity production, and after carbon dioxide separaration also as vehicle fuel. Bio-fertilizer, which is a rest product from the digestion process, has a high content of nutrients and is therefore beneficial for agricultural use.