Understanding Our Process

Anaerobic Digestion 101:
  • Anaerobic digestion is simply the controlled decomposition of organic waste in an oxygen-free environment
    • Anaerobic digestion is very similar to composting, which itself is the controlled decomposition of organic waste in an aerobic (as opposed to anaerobic) environment
  • Anaerobic digestion at the commercial scale occurs inside a large airtight reactor tank, where naturally occurring anaerobic microbes consume organic waste and in turn generate both a methane-rich biogas and an odor-free, pathogen-free, nutrient-rich organic slurry
  • Anaerobic digestion is a proven and economically-viable "green" technology, with a decades-long track record of successful project development and operation, and with leading edge modern applications primarily fed with food scraps and separated industrial, commercial, and municipal organic wastes
Freestate Farms utilizes anaerobic digestion for heating, powering, fertilizing, and sustaining its own advanced commercial greenhouse facilities, and we also market our remaining renewable energy and agricultural co-products to public and private sector off-takers.

Process Elements:

  • Source separated and packaged organic waste from grocery stores, restaurants, cafeterias, commercial kitchens, and distribution centers.
  • Agricultural waste products (unsaleable produce, silage, green waste).
  • Industrial organic waste (food and beverage processing, personal care and other specialty products).

Digester Reactor
  • Systems vary in size, shape, feedstock preprocessing, digester process flow, gas capture, temperature, and pH.
  • Common reactor types include continuously stirred tanks, plug-flow processes, and dry batch "garages."
  • A typical continuously stirred tank reactor is approx. 50-80 ft. high (including capture dome above), with a series of agitators and pumps to keep the microbes in contact with feedstock.

Agricultural Co-Products

  • Digestate slurry, which is largely odorless and free of pathogens, can be separated into liquid and solid components and otherwise tailored into valuable non-synthetic fertilizers and soil amendments.
  • Co-products may also be "cured" by a brief aerobic composting period, either alone or mixed with traditional wood waste in an optimized process.


  • A primary and natural process output is biogas, which is approx. 60% methane (i.e., 60% traditional pipeline natural gas) and 40% carbon dioxide. Biogas is available 24/7/365 and can be used for various baseload renewable energy purposes, including:
  • Combine Heat and Power connected to our co-located commercial greenhouse, and the excess of which can made available for sale to the electric grid.
  • Compressed Natural Gas (after biogas conditioning and upgrading) for our own vehicles and sales to local governments, commercial fleets, a private citizens.

Commercial Greenhouse
  • Controlled environment agriculture with automated controls and mechanical systems, hydroponic growing system, high quality non-synthetic fertilizer and soil amendment, and injected carbon dioxide gas all contribute to robust production capacity.
  • Potential crops include (but are not limited to) tomatoes, peppers, cucumbers, and lettuce varieties.
  • Unsellable and other waste products are fed back into the digester, thus completing the loop.