A team in Denmark has analysed the various ways in which Danish companies treat pig manure and use it to generate electricity in systems such as anaerobic digesters or incinerators.
The team, led by Trakarn Prapaspongsa at Aalborg University, found that for high-efficiency energy production, anaerobic digestion is the answer. But if minimising greenhouse gas emissions takes priority, the best option was to separate the solid from the liquid waste, dry the solids and incinerate them.
In anaerobic digestion, bacteria break down waste material by warming it in an oxygen-free vessel, releasing methane which is used in gas turbines. Incinerators burn material to boil water and drive a steam turbine.
• SAGE journals online©