Today, recycling methane gas is not only a growing source of energy generation, but also an effective means of preventing greenhouse gas from polluting the atmosphere and turning it into a valuable revenue stream.
Reducing methane is also a hot issue among environmental and climate change advocates, relative to lowering greenhouse gas emissions.
To that end, in June 2013, president Obama issued his broad-based Climate Action Plan, announcing a series of executive actions to reduce carbon pollution and lead international efforts to address climate change.
Earlier this year, a key part of that plan was released with the administration’s Strategy to Reduce Methane Emissions. This Strategy summarizes sources of methane emissions, commits to new steps to cut emissions and outlines efforts to improve emission measurements.
The administration wants to further cut methane emissions from landfills, oil, and gas systems, coal mining and agriculture through cost-effective voluntary actions and new federally regulated standards.
Followed by carbon dioxide, methane (also called marsh gas) is the second most prevalent greenhouse gas emitted in the U.S. from human activities. In 2012, methane represented about nine percent of all U.S. greenhouse gas emissions from human activities. Globally over 60 percent of total methane emissions come from human activities with the balance generated from a number of natural sources such as wetlands.
The big problem with methane – it is more efficient at trapping radiation than carbon dioxide. According to the U.S. EPA, pound for pound, the comparative impact of methane on climate change is over 20 times greater than carbon dioxide over a 100 year period.
Ironically, since 1990, methane pollution in the U.S. has actually decreased by 11 percent, even as activities that produce methane have increased. However, methane pollution is projected to increase to a level equivalent to over 620 million tons of carbon dioxide pollution in 2030 without additional action to reduce emissions.
Two sources of methane emissions that hold the greatest potential for recycling are landfill gas which accounts for 18 percent of all U.S. methane emissions and natural gas and petroleum production, accounting for 29 percent. More difficult to recycle are coal gas from mining, animal manure, enteric fermentation (intestinally produced by humans and animals) and miscellaneous sources, which account for the balance of methane emissions.
This summer the EPA will propose updated standards to reduce methane from new landfills and gather public comment on whether to update standards for existing landfills. As we know, landfill gas (LFG) is created as solid waste decomposes in a landfill. This gas consists of about 50 percent methane (the primary component of natural gas), about 50 percent carbon dioxide and small amounts of organic compounds.
Putting LFG to use can support local economies with sources of clean energy that generates revenue, spurs investment and jobs, improves safety and leads to cleaner air. According to the U.S. EPA, there were 636 operational LFG energy projects in the U.S. As of January 2014, approximately 450 landfills are good candidates for LFG projects. Of the approximately 2,400 currently operating or recently closed municipal solid waste (MSW) landfills in the U.S., more than 580 have LFG utilization projects. EPA also estimates that approximately 450 additional MSW landfills could turn their gas into energy, producing enough electricity to power nearly a half-million homes.
The country’s largest operator of LFG-to-energy projects is Waste Management Inc. (WM), an environmental solutions provider serving more than 20 million customers in North America.
Sue Briggum, WM’s vice president of federal affairs commented on the administration’s new plan. “When the methane strategy came out there wasn’t much that was a surprise to us. One thing they mentioned, of course, was the fact they are hoping to update the standards for methane releases at landfills. We have been working with EPA for over a year on that proposal. EPA is getting down to the final details in terms of making sure that strategy reflects the best technology for assessment of methane from landfills and the best control technology. So we felt very comfortable with that. We were also pleased to see the administration cite with favor its Landfill Methane Outreach Program (LMOP), which encourages the development of LFG to energy projects across the country.”
Susan Robinson, WM’s director of public affairs, added, “At most of our landfills we are using recovered methane to create electricity. But we are also using our methane to create renewable natural gas (RNG) to fuel our trucks. At our Altamont Landfill in Livermore, California we make approximately 13,000 gallons of renewable, liquefied natural gas (LNG) a day, which powers nearly 300 of our trucks in California, about one-third of our state fleet. That reduces our greenhouse gas emissions by over 90 percent compared to the diesel trucks they replace. Ninety percent of Waste Management’s new truck purchases each year will be natural gas (NG) vehicles. Currently over 3,100 of our nearly 18,000 heavy duty vehicles are powered by NG. We are now building another facility in Illinois that will also make renewable natural gas from methane, and we have begun construction of a plant in Oklahoma that will convert landfill methane to renewable diesel fuel. So we are taking advantage of these technologies to create both renewable electricity and fuels. “
Another way to curb LFG emissions is an avoidance strategy that reduces the volume of organic material going to landfills and recycles it through anaerobic digestion to produce both biogas to power electric generation and compost, or make compost alone for fertilizer.
Sue Briggum expanded on WM’s efforts to recycle methane from organics. “We have 137 LFG projects generating 682 megawatts of electricity. The only reason we would flare landfill gas is as a control in the beginning and at the end of the landfill life cycle when there is too little gas being emitted to support a gas collection system.
As a general matter, our landfill gas collection systems are extremely efficient and do an excellent job of capturing the methane. All of this is part of an air permit that makes sure you have best controls sufficient both to meet both Clean Air Act and Resource Conservation and Recovery Act (RCRA) standards for control of methane.”
Robinson explained, “We also have a team of folks dedicated to our organic recycling projects. Last year we diverted about 2.5 million tons of organic material and have about 40 compost facilities in the U.S. and Canada to specifically manage various types of organics whether yard waste or food waste.
In a lot of communities across the country we’ve diverted most of the yard waste from landfills and that is primarily going to composting. Composting handles a lot of volume very efficiently so it’s a great solution.
Our customers are very focused on looking for solutions for recycling food waste. In order to meet their aggressive diversion goals from a municipal perspective, we have been developing both residential and commercial solutions. We have also invested in our recently patented CORe technology, for commercial food waste, where we process commercial food waste for anaerobic digestion at existing wastewater treatment facilities,” Robinson concluded.
Nearly one-third of methane emissions comes from oil and gas drilling and production operations, and especially from leaking natural gas pipeline infrastructure. The boom in shale gas production led by new applications of hydraulic fracturing and horizontal drilling technology has led to major increases in U.S. reserves of natural gas. Building on success in reducing methane emissions from the oil and gas sector through voluntary programs and targeted regulations, the Administration plans to take new actions to encourage additional cost-effective reductions.
One company, Primus Green Energy, based in Hillsborough, New Jersey, claims to have an innovative solution; in essence a process that captures natural gas and methane leaking or being flared into the air and recycles it into liquid fuel. Primus has developed a highly efficient thermochemical gas-to-liquids (GTL) conversion process which produces gasoline, jet fuel or diesel. These fuels are usable directly in gasoline, diesel or jet fuel engines without any modification or adjustment.
George E. Boyajian, PhD and vice president of business development at Primus explained, “Whether it’s Obama’s, or anybody’s strategy to reduce methane emissions, you have to pipe the natural gas coming out of the well to the market. At every step along that way from the well-head to where the gas is consumed there is a chance for leaks to occur. What our system does is take the natural gas right next to the well-head and converts it into a liquid fuel. That enables us to eliminate all the leaks downstream from the well-head. If we put our plant right at the well site we can take the natural gas and make it into a liquid product so methane could not escape into the atmosphere.
“Biogas or landfill gas also has methane in it. Not as concentrated as natural gas, but I think a combination of landfill gas and natural gas would make a very good combination for us. We are looking at projects in several parts of the country to take landfill gas and turn it into liquid fuels.
“The other way we help is not only on the methane side, but is also on the carbon dioxide side. If you are flaring the gas at the well-head, or at a landfill, or if your flaring is just so the gas does not build up and explode, we can turn that flare gas methane into liquid product as well. At least we can make useful energy out of it before it goes into the atmosphere.”
Boyajian noted that Primus is issuing a white paper that describes exactly the size and configuration of a system that would make about 350 to 500 barrels of liquid fuel per day out of natural gas from a single well at costs competitive with traditional liquid fuels. He believes that the wells in the Bakken region of North Dakota that are flaring gas could be producing liquid fuels instead of being wasted and sending methane into the air.
With oil and natural gas production and distribution accounting for nearly one-third of all U.S. methane emissions, and coal mining representing 10 percent, it appears that greater reliance on clean energy production such as wind and solar can also play a larger role in reducing methane emissions and avoiding harmful climate change.
Published in the July 2014 Edition of American Recycler News