City Council
MEETING DATE: 5/24/2017
TITLE:
Title
Trash to Energy Pilot Project (anaerobic digester)
End
FROM:
Pat Milos, Community Development Director
RECOMMENDATION:
Recommendation
This item is provided for information, discussion and direction only.
Body
BACKGROUND:
Anaerobic digestion (AD) is a biological process typically employed in many wastewater treatment facilities for sludge degradation and stabilization, and it is the principal biological process occurring in landfills. Many livestock farms in the U.S. are turning to the use of AD as a means of mitigating the environmental impacts of manure lagoons with some capture of methane for energy production.
Internationally, AD has been used for decades, primarily in rural areas, for the production of biogas for use as a cooking and lighting fuel. Many household-scale digesters are employed in rural China and India for waste treatment and gas production. More recently, Europe has developed large-scale centralized systems for municipal solid waste treatment with electricity generation as a co-product. Other industrialized countries have followed the European model.
Biodegradation of organic material occurs in nature principally through the action of aerobic microorganisms. Ultimately, complete oxidation of the carbonaceous organic materials results in the production of carbon dioxide (CO2) and water (H2O). Anaerobic microorganisms degrade the organic matter in the absence of oxygen with ultimate products being CO2 and methane or "biogas". Anaerobic microorganisms occur naturally in low-oxygen niches such as marshes, sediments, wetlands, and in the digestive tract of ruminant animals and certain species of insects.
The “biogas” can be captured, processed into renewable natural gas (biomethane), and used. Cities and counties across California are developing facilities that will harness this natural process to produce renewable energy from waste, as well as compost for fertilizer.
Biogas is upgraded to biomethane by removing carbon dioxide and impurities. Biomethane can be used as a transportation fuel in compressed natural gas (CNG) vehicles or used in fuel cells, turbines or internal combustion engines to generate electricity.
The City has received a request to consider a pilot waste to energy project in Cathedral City.
DISCUSSION:
Case Example: Monterey Regional Waste Management District 8
Located just north of the City of Marina, the facilities of the Monterey Regional Waste Management District (the District) now includes a new pilot project. Operational since March of 2013, this small anaerobic digestion facility features a 5,000 ton input capacity and produces approximately 100 kW of electrical energy annually. This first in California “dry fermentation” anaerobic digester is fueled with a mix of 70% food waste from area restaurants and college campuses, and 30% yard trimmings.
The project is in the middle of its initial phase as a 5-year pilot project. The District explored anaerobic digestion as a method for processing the increasing volume of food waste received at the site and the desire of the local hospitality industry to keep this material out of the landfill and put it to better use. Zero Waste Energy (ZWE), LLC, was looking for an opportunity to prove the practicality of their new technology. The District agreed to host the pilot project and provide the site on land previously zoned for a composting facility. In exchange ZWE provided the “SmartFerm” system for a 5 year term without requiring the $3 million purchase upfront. The District pays ZWE a fee on each ton of material processed and ZWE receives the revenue from electricity sales which supply the neighboring waste water treatment plant.
The gas produced by the process serves as fuel for an engine generator producing 100 kW of electricity. The electrical output sold “over the fence” is enough to replace 10 percent of the energy needed to run the adjacent waste water treatment plant. The digestate produced by the facility is given to a private firm who rents part of the district’s land for an on-site composting facility. This private firm is then responsible for all the marketing and sales, mostly to local vineyards, of the resulting compost.
Jeff Lindenthal, the Monterey Regional Waste Management District’s Director of Community Programs, says that the business community was instrumental in making this project a success and were the driving force behind getting food scraps out of the landfill and into compost. They are, “proud to know that their food waste is going to a state of the art facility where the methane is being converted into electricity for local use.” The District worked cooperatively with the hospitality industry to create an “Organics to Energy” brand and an informative website which showcases the project and the participating hospitality businesses sending their food waste to the program.
Case Example: Perris 9
Construction is underway as the City of Perris aims to build the largest anaerobic digestion facility in the world. Phase one was completed in 2015, with three additional phases (each of the equal size) already permitted on the 52 acre site.
Developed by a private firm, CR&R Incorporated, each phase of this facility will process 83,000 tons of organic waste per year from curbside collection of “green material” and food scraps (for a total of 335,000 tons/year). Each phase will produce an amount of biogas equivalent to more than 1 million gallons of gasoline each year, enough fuel for 70 collection vehicles. The quality of the fuel has already been approved for pipeline injection, so that extra fuel produced can be sold elsewhere.
Mike Silva, Project Manager at CR&R, praises the support they received from the city and community from the very beginning, “The number one thing is that you have got to have the support of the community. The rest is all technical: getting your permits, dotting your i's, crossing your t’s. If you don’t have the support of the community all the rest is a waste of time.”
The first two phases have been partially funded by grants from the California Energy Commission, South Coast Air Quality Management District, and CalRecycle.
FISCAL IMPACT:
There are no fiscal impacts with this action
ATTACHMENTS:
1. Current Anaerobic Digestion Technologies Used for Treatment of Municipal Organic Solid Waste
2. Institute for Local Governments article "Anaerobic Digestion, what it is and who is doing it"