ABSTRACT
This chapter illustrates on-farm anaerobic digestion (AD) schemes which are more efficient and allow the introduction of off-farm feedstock such as products and by-products from food processing plants, municipal food and other green waste sources. It discusses some key feedstock issues, which include, quantity, supply stream, quality, volume, and feedstock energy outputs. In smaller-scale schemes the AD plant manufacturer may have biogas yield figures for a range of different feedstocks; food waste, human waste, grass cuttings, etc. The chapter discusses the animal by-products (ABPs) which are classified into three categories, based on their potential risk to animals, the public and the environment. The following are the three official EU categories but the same is largely true in the USA. These include, category 1 material is the highest risk; category 2 material is also high-risk material; and category 3 materials are low-risk materials.
