Mountains of waste are literally piling up in landfills around the world, and the organic material in those heaps of trash is a significant source of methane, a powerful greenhouse gas. That’s the bad news.
The good news is that emerging waste-to-energy technologies are making it more cost-effective to capture energy from waste. That provides businesses seeking more sustainable and energy-efficient processes with another opportunity to support clean technologies and help to build a more resilient global economy.
Incinerating waste to generate electricity is commonplace, as is capturing and re-using landfill gas as fuel. However, both of these waste-to-energy systems are becoming outdated as new, more sophisticated systems enter the marketplace.
One example of this transformation is the California-based company Sierra Energy. The company’s FastOx system takes on the challenging problem of reclaiming energy from a mixed-waste stream containing food and other organic wastes, as well as metals and non-organic materials, both of which are challenges typically present within municipal solid waste.
Biomass is another ideal feedstock for the FastOx system. It can also handle many other materials including auto shredder residue, railroad ties, medical waste, hazardous waste, tires, construction waste and industrial waste.
That all-encompassing strategy caught the eye of the U.S. Department of Energy, the U.S. Army and the California Energy Commission. All three agencies contributed funding for Sierra to develop the FastOx system through a demonstration facility installed in 2017 at Fort Hunter Liggett in Monterey County, California.
The company says the installation will help the U.S. Army and DoD reach their zero-waste goal, as well as decrease their risks, costs and carbon footprint resulting from the transport and disposal of trash.
Basically, the FastOx system works like a blast furnace. Instead of feeding in fuel, however, FastOx creates its own fuel from the organic material in the waste stream.
Steam and oxygen are injected into the bottom of this system, and shredded waste is fed into the top. When the waste reaches a temperature range of 300°F to 1,000°F, the system produces a mix of light gases and condensable hydrocarbons from the organic waste. As these hydrocarbons react with the steam and oxygen, the system produces temperatures up to 4,000°F.
The ultra-high temperature converts the remaining carbon into synthetic gas fuel (a.k.a. syngas) consisting mostly of carbon monoxide and hydrogen, which makes the process self-sustaining.
Due to the high heat, metals and other inorganic compounds melt without producing nitrogen oxide and other toxic byproducts.
In addition to recovering solid materials, the system also recovers carbon monoxide and hydrogen, both of which can be used as fuels.
According to Sierra Energy, FastOx can process 20 tons per day of municipal solid waste and biomass, producing electricity and diesel fuel that is 20 times cleaner than the California’s fuel standard.
The taxpayer-funded kickstart worked as intended, enabling Sierra to catch the interest of private sector investors.
Last month, the company received $33 million in Series A funding led by the clean tech investment group Breakthrough Energy Ventures, funders of which include Bill Gates and other leading global investors.
Additional investors include Cox Investment Holdings Inc., BNP Paribas SA, Twynam Investments, Formica Ventures and The March Fund I LP.
By providing businesses with a way to divert their waste into useful products, systems like FastOx take a local issue and scale it up so that the outcome an become an important part of global action taking on climate change.
More than a third of this waste is disposed in landfills, and only 8 percent of landfills are currently fitted with landfill gas collection systems.
Here in the U.S., waste management is the third-largest source of human-related methane emissions, behind only energy production and agricultural operations, according to the U.S. Environmental Protection Agency (EPA).
Considering the urgency needed to accelerate climate action, the pressure will increase on U.S. businesses to decarbonize their waste streams as well as their supply chains. Fortunately, it seems that new technology is bringing the solution to hand.
Tina Casey also contributed to this report.
Image credit: Pasi Mäenpää/Pixabay
Laurel has extensive experience writing about energy efficiency, clean energy, sustainability and green building. She was formerly Senior Energy Content Specialist for a digital marketing firm serving the utilities industry where she generated story ideas and wrote content for several e-newsletters. Laurel is also a member of the Ohio chapter of the U.S. Green Building Council and participates on several committees for the Central Ohio region.