WA S T E - T O - E N E R G Y
by Alain Castro "The project’s success is imperative, given that the air emission rules in Southern California are slated to get tougher in January 2016."
THIS OLD LANDFILL
Turning Low-Quality Gases into Clean Energy for Santiago Canyon Landfill Project
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n January 2015, the California Energy Commission awarded a $1.5 million grant to the University of California, Irvine’s Advanced Power & Energy Program (APEP) in order to facilitate renewable energy projects. These funds now represent the start of a project at the Santiago Canyon Landfill, where 1,000 cubic feet of methane is currently being flared every single minute. Methane is a far more potent greenhouse gas than CO2; one molecule of methane traps 25-30 times more heat in the atmosphere than an equivalent molecule of CO2. The standard practice for older (closed) landfills is to flare gas, as has been done historically at Santiago Canyon ever since the landfill closed in 1996. However, by merely flaring away this greenhouse gas to comply with environmental regulations, and attempt to slow down its global warming effects, a major economic opportunity is being missed. Surprisingly, local Irvine-based company Ener-Core, Inc. can now turn these poor-quality gases into electricity, which can generate revenue for the landfill, produce clean energy for the county, and also enable this old landfill to actually exceed the emissions reductions that are achieved with a flare. In the coming months, Ener-Core will install a proprietary power-station that will directly convert the low-quality methane to electricity at the landfill, as part of a new partnership between Ener-Core, the County of Orange and APEP. This project will not only benefit the local community, but will also represent a big shift at a global level, as there are thousands of closed landfills around the world that currently emit greenhouse gases. The project’s location at the landfill has been approved by the Orange County Board of Supervisors, and detailed design and work for the project has already begun. Although the project won’t start generating electricity until 2017, Ener-Core’s Power Oxidizer is planned to provide approximately $250,000 per year worth of electricity to the county— without a price tag attached. And unlike wind and solar technologies, the Power Oxidizer is unique in that it can utilize a low-quality waste gas as a fuel and turn it into two valuable resources: clean electricity and money. So how does the technology work? The process starts with emissions being sent into a heated pressure vessel. As the temperature rises, a natural chemical reaction called oxidation begins, without any flame or any type of ignition. Methane and oxygen go into the vessel and water, carbon dioxide and heat come out. A ceramic bed retains the heat inside of the vessel, thereby creating a self-sustaining reaction as long as the waste fuels continue to come in. The heat that comes out spins a turbine to generate electricity, all while producing near-zero nitrogen oxide emissions. The system does not use any catalysts, and it manages to accelerate the natural oxidation reaction (which typically takes 10-20 years for methane in the atmosphere) such that the entire reaction takes place in approximately two seconds. At the Santiago Canyon Landfill, about one-fifth of the landfill emissions will be diverted to Ener-Core’s three-year-long project, which will produce 250 kilowatts of electricity, enough to power approximately 350 homes. Effectively, the project will also prevent one ton of nitrogen ox-
Oxidizer test vessel operated on site by Ener-Core engineers.
ides—another harmful pollutant—from getting into the atmosphere per year. If successful, the technology could be emulated at landfills across the state, providing electricity for hundreds of thousands of homes. Moreover, according to data from the Landfill Methane Outreach Program (LMOP) of the U.S. Environmental Protection Agency, at least 50 percent of the landfills in the U.S. are already at full capacity and hence closed. When landfills close, the solid waste within them continues to decompose at a slow rate, and this ongoing decomposition typically results in the ongoing emissions of harmful greenhouse gases for as long as 50 to 70 years after their closure. However, the quality of these gases typically falls drastically October/November 2015 www.solidwastemag.com 15
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