Next Generation Anaerobic Digstion

The state-of-the-art features of the latest generation of anaerobic digestion installations are discussed. High performance processes include pre-treatment hydrolysis (thermal, acid, C. bescii), mesophilic, and thermophilic digestion. Some of the largest installations in the world are given as examples. Examples of co-digestion installations are given including an energy neutral water resource recovery facility that co-digests fats, oils, and grease (FOG) near its maximum organic loading rate. Promising results from research on the biological C. bescii bacteria hydrolysis process for the digestion of cellulose and lignin is presented as an example of the next generation of anaerobic digestion. Digestion of condensate from pyrolysis is given as an example of another process to digest recalcitrant cellulose and lignin.

The latest generation of anaerobic digestion include processes and features for optimizing capacity, performance, and reliable operation. They have state-of-the-art systems such as sludge grit removal, thickening, sludge screening, raw sludge feeding and digested sludge withdrawal and dewatering. Some have systems that harvest nutrients and prevent struvite or vivianite scaling. Ammonia loads to the liquid treatment process are addressed with sidestream treatment. All have a high performance, digestion process such as high rate mesophilic, thermal or biological hydrolysis before mesophilic or thermophilic digestion. The digester structure, cover, heating and mixing systems are state-of-the-art. The latest digester gas collection, treatment, and utilization system are incorporated. These components of state-of-the-art digestion for resource recovery of biosolids, nutrients, energy, and water are discussed.