Valuing Feedstocks for Anaerobic Digestion -- Balancing Energy Potential and Nutrient Content
Channel: Livestock & Poultry Environ. Learning Community
Date: 2013-05-23

Proceedings available at: http://www.extension.org/67610

To improve the energy production and revenue generation, many farm digester operators are including off-farm feedstocks in the blend.  Off-farm feedstocks are raw materials with high carbon concentrations that can be degraded anaerobically.  Common off-farm feedstocks include food service or retail waste, food processing byproducts, residuals from biofuels production and FOG (fat, oil & grease) resulting from food preparation.  Typically, off-farm feedstocks have a higher energy potential when compared to manure.  Manures generally have biogas potential in the range of 280 to 500 L of biogas/kg of VS, compared to off-farm feedstocks which can range from 300 to 1,300 L of biogas/kg of VS [1].  In addition to the increased biogas production, revenue can also be generated from tipping fees collected for feedstock brought onto a farm.  The tipping fee is typically comparable to the cost of disposing of the material at a landfill or wastewater treatment plant.