Pig farms occupy an important place in the livestock sector in Portugal. As the industry has evolved in the last decades, pig production has become more concentrated and from this intensive farming considerable amounts of manure inevitably arise. Despite presenting many environmental challenges, animal manure can be viewed as an important source of bioenergy; in fact, manure-based energy can be especially interesting for local pig farms in Portugal as it can help reduce environmental externalities of animal production, alleviate financial pressure on farm owners, and provide clean energy. The main methods available for renewable energy extraction from animal manure include thermochemical and biochemical conversion processes Shen 2015.