High Quality Fiber and Fertilizer as Co-Products from Anaerobic Digestion

Anaerobic digesters have yet to be adopted on a large scale by animal agriculture producers, largely because they are capital-intensive, low cost-return structures. To make digesters more attractive, additional revenue streams besides methane are needed to improve the feasibility of the technology. Additionally, the digestion process alone contributes little to reducing manure nutrients. Thus, complementary processes are required to meet excess nutrient related environmental challenges. The goal of this project is to improve feasibility of AD by producing high quality fiber and struvite (MgNH4PO4.6H2O). The high quality fiber can be sold as a substitute for peat moss while the struvite, produced through precipitating P and N from liquid manure by adding Mg ions, can be used as a slow-release fertilizer.