Large Scale Composting Using Anaerobic Digesters


1) Waste: Food waste is a huge problem. Not only does the food waste occupy limited landfill space, the food waste will not efficiently decompose when it is mixed with other non-organic materials. Additionally, if not properly managed, the methane released from the decomposing organic matter exacerbates the effects of global warming. Capturing this methane can also provide an energy source from something otherwise going into the waste stream.

2)  Title: High Solids Anaerobic Digestion + Composting In San Jose

Website Name:


Developer and Owner: Zero Waste Energy Development Company (ZWEDC)

  • The article describes a 10,000-square foot facility in San Jose, California which processes up to 90,000 tons of organic waste each year.
  • In addition to processing organic waste, the facility produces biogas which is used to power a combined heat and power plant which is used to operate a recycling facility which recycles various segregated construction debris materials.  This technology replaces diesel, used in older processing plants. Any unused biogas-generated power is fed into the grid.
  • The plant was deployed in 2012 in response to the City of San Jose’s Green Vision goal to divert 100% of the city’s waste from the landfill by 2022.
  • Once the costs of the improvements are covered, the city will receive $4 for every ton of waste brought into the facility, providing a revenue source for the city.
  • Of the organic wastes brought into the facility, 70% are organic wastes as they should be, and 30% are contaminants which are sorted out.

3) Organizational Stakeholders: Local Governments; Department of Sanitation; Energy Utilities; Individuals & businesses who will start collecting their organic wastes; Agricultural entities who can use the composted final product; Landfill owners; Recycling Facilities; Waste Haulers; Manufacturers of the processing equipment; Landowners

4) First 3 steps in deploying this technology:

  • Team up with local governments and sanitation departments
  • Draft a plan to integrate the new technology into the system
  • Begin constructing appropriate infrastructure

One thought on “Large Scale Composting Using Anaerobic Digesters

  1. The dry batch digestion technology utilized by ZWED requires minimal feedstock processing and no water addition prior to fermentation, significantly reducing pre-processing costs. In addition, no pumps or motors in a dry anaerobic digestion system come into contact with the waste, which reduces process requirements & minimizes maintenance downtime. Although some wet systems can generate slightly more biogas than similarly sized dry AD systems, the lower internal energy usage and costs associated with dry batch systems outweigh the potential biogas generation benefit.


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