Anaerobic Digestion

Anaerobic Digestion is a controlled process by which organic materials (those with plant and animal origins) are transformed by organisms that thrive in an environment without oxygen.  The process produces a nutrient rich soil amendment and biogas, primarily methane, which is used as a renewable replacement for natural gas.  Casella Organics is committed to expansion of this technology to expand recycling options for organic materials.  We recover biosolids, food processing byproducts and other feedstock for anaerobic digestion and market fertilizer products derived from digestion.

Casella Organics advises the operation of two anaerobic co-digesters in Massachusetts.  The "first" in the state at Jordan’s Dairy Farm in Rutland, Massachusetts and the second at the Barstow's Longview Farm in Hadley.  These facilities are co-digesting dairy manure produced by the host farm and food residuals (commonly known as ‘source separated organics’ or ‘SSO’) diverted from food processors. This material arrives at the site in closed containers and is loaded into the digester where it is processed without exposure to air – from there the material spends approximately thirty days in-process before being removed and stored as a stabilized fertilizer product.  This liquid product is then used during the growing season by the farms and their neighbors as a recycled liquid fertilizer, replacing both synthetic fertilizer products and traditional raw manure spreading.

The biogas produced during the stabilization of the in-process material is used to power a small combined heat and power unit, or CHP unit, consisting of an engine and a generator which provides electricity and heat to the farm’s buildings.  Surplus electricity is distributed through the power grid.  

This "closed-loop" recycling program is a local and sustainable program that is mutually beneficial for all involved.

We are always looking for more “stuff” to recycle at our anaerobic digesters, especially high-strength liquid food residuals.  If you believe you have some material appropriate for this type of recycling, or you would like assistance operating your an anaerobic digester or sourcing feedstock for a digester, please contact us.