Home Magazine Landfilling up

When most people think of renewable resources, they usually don’t think about trash as a source of fuel for natural gas vehicles.

Here’s how it works: After waste is placed and covered in a landfill, it decomposes, creating a gas. This gas consists of about half methane and half carbon dioxide. Since methane is the same primary constituent as natural gas, renewable landfill gas can be used to replace fossil fuel natural gas. The landfill gas is collected by drilling wells into the waste throughout the landfill. The wells are connected to a central pipe and a vacuum is placed on the pipe to withdraw the landfill gas from each well. Using specially selected membranes and adsorption media, the carbon dioxide and other minor constituents are filtered out of the landfill gas, leaving methane with the same quality as natural gas. Next, the gas is compressed until it can be injected into a natural gas pipeline or used directly on-site as a compressed natural gas (CNG) fuel. The gas also can be chilled, creating liquefied natural gas (LNG) fuel.

Using the same filtering process at Waste Management’s (WM’s) Altamont Landfill in Livermore, California, the company feeds the purified gas stream into a liquefier where it is chilled until LNG is produced. Its plant in California fuels 300 of its local trucks every day. With this innovative facility, WM has created an environmental closed loop, as the waste it collects in Bay Area communities is the same fuel that powers its trucks on their streets. What’s more, the greenhouse gas emissions associated with this fuel are 20 to 25 percent lower than those of diesel, and particulate emissions are 90 percent lower. It is the cleanest fuel available for heavy-duty trucks today.

WM is nearing completion of a new facility that will produce 105 million British thermal units (Btu) per hour of pipeline-quality renewable natural gas from our Milam Landfill in East St. Louis, Illinois. This processed natural gas will be injected into an adjacent natural gas pipeline, and withdrawn at its own CNG truck fueling stations across the country, as fuel for its CNG truck fleet.
 

Natural gas pioneers

WM has been a pioneer in the use of natural gas in its fleet since the early 1990s. In 2007, as part of its corporate sustainability goals, it committed to increase its fleet’s fuel efficiency by 15 percent and reduce its fleet emissions by 15 percent, both by 2020. WM accomplished a 20 percent emissions reduction by 2012, beating our goal by eight years. Achieving this goal yields significant benefits including savings of 350 million gallons of fuel, about 3.5 million metric tons of carbon dioxide (CO₂) emissions and $1 billion in operational costs.

WM’s fleet currently includes more than 3,200 natural gas trucks, the largest of its kind in the waste industry. With more than 32,000 collection and support vehicles on the road throughout North America, WM is committed to reducing the environmental impacts of these vehicles and reducing its emissions and improving our fuel efficiency. Our vehicles powered by CNG emit nearly zero air particulates, cut greenhouse gas emissions (based on replacing diesel trucks that are 2006 and older) by nearly 25 percent and are far quieter than their diesel predecessors. WM also operates 61 fueling stations in North America. The company constructs its own fueling stations, which it owns and operates. WM purchases the fuel and finances the construction of the stations.

WM is uniquely situated in the renewable fuels industry by having control of all aspects of the process from start to finish. Its steady flow of feedstock is the waste it picks up at the curb every day. WM owns and operates the landfills and the gas collection systems that produce the landfill gas. Its internal renewable energy team oversees the design and operates the facilities that process the landfill gas into renewable vehicle fuel. With one of the largest and fastest growing natural gas fleets in North America, it has the demand to utilize the fuel it generates.
 

Smart business

The strategy of using its own feedstock, waste, to fuel its underlying operations infrastructure will continue to be an important directive. It not only makes environmental sense, it makes business sense. The U.S. Environmental Protection Agency’s (EPA’s) Renewable Fuel Standard and state low-carbon fuel programs provide the additional value needed for projects to meet their financial objectives. As WM continues to transition its truck fleet from diesel to natural gas, it will pursue additional landfill gas projects to meet the additional demand.

WM has 134 projects that use landfill gas as a renewable resource. At 107 locations, small on-site power plants use landfill gas as fuel to produce renewable electricity that is delivered to the utility power lines. Like wind and solar, electricity produced from landfill gas is endorsed by the EPA as a renewable resource and an alternative to fossil fuel. The remaining 27 landfill gas projects provide landfill gas as a direct substitute for fossil fuels in applications such as boilers and burners, or it can be processed and injected in natural gas pipelines. WM fits into the big picture by being pioneering and smart about its energy-related strategy.

Those of us at the Securing America’s Future Energy (SAFE) event in Washington, D.C., agreed that the best solutions for alternative fuels to continue to emerge in America will inevitably come about when industry, labor, government and environmental groups work together to move the nation toward a more energy-independent model.

I applaud these other groups’ wise approaches and leadership—and that of our military leaders—in pressing to meet these challenges. On the occasion to mark 40 years since the first OPEC oil embargo, which caused severe oil-related energy shortages in the U.S., it is essential to do everything we can to reduce our reliance on foreign oil. The advances being made today to harness renewable fuels and to unlock energy reserves in our country will help us achieve the energy security that is so vital.

Beyond business, economic and security reasons, I’m most excited about the opportunity to help hand over the planet to the next generation in better condition than when we received it. Fostering energy diversification and energy security is one way we can live up to this promise.

The author is vice president, renewable energy for Houston-based Waste Management.