Biogas as a Waste Management Solution

The Environmental and Energy Study Institute (EESI) and the American Biogas Council (ABC) held a briefing about the numerous challenges posed by organic wastes—to human health, water and air quality, and to businesses that must manage these wastes—and how anaerobic digestion offers solutions to these pressing issues. Anaerobic digestion is the process of converting organic materials, typically viewed as wastes, into usable products, including biogas, renewable natural gas (RNG), as well as valuable organic fertilizer and compost. These biogas systems turn a waste management issue into a revenue opportunity for America’s farms, dairies, food processing, and wastewater treatment industries. Speakers for this forum discussed the tremendous opportunities for rural and urban communities alike to use anaerobic digestion systems to foster healthy communities and businesses.

Waste management issues are becoming increasingly pressing in the United States, as 17 million tons of waste are produced each year, including edible and inedible waste. Biogas and anaerobic systems provide an opportunity to create economic activity while revolutionizing waste management.

Briefing Highlights

 

Rep. Scott Peters (D-CA)

• Rep. Peters began by declaring that “the upside of not passing the [House] Farm Bill was not passing the Farm Bill.” He said the bill would have hurt small and rural farmers. Among other things, it would have eliminated the overall Energy Title, redirecting programs to other Titles instead. It also provided no mandatory funding for these programs. A good Farm Bill would support small farmers and sustainable forms of agriculture, which includes utilizing wastes generated on farms for power and biobased products.
• We need to create demand for biogas and for carbon. We should also advance clean energy and carbon utilization technology, as doing so is necessary to keep global warming under 2 degrees Celsius. We should also promote research and investment in advanced energy technology.
• Algae may be a powerful tool for the future as it can be used instead of petroleum to create plastics and also as a biofuel.
• “Waste is three things: a revenue opportunity, a sustainable and affordable energy source, and a crucial part of our strategy to slow and reverse the effects of climate change,” said Rep. Peters.
• As the 3rd ranking Democrat on the Energy Subcommittee of the House Energy and Commerce Committee, Rep. Peters hopes his subcommittee can be a resource for those working towards biogas and other innovative and renewable uses of resources.

 

Patrick Serfass, Executive Director, American Biogas Council.

• The American Biogas Council (ABC) represents the entirety of the American biogas industry. While there are other regional groups that do work on behalf of biogas, ABC is a national advocate for the industry.
• Anaerobic digestion converts organic material into gas, liquid and solid streams, each of which can be turned into different products. The organic material used in the process is typically manure and wastewater biosolids (the result of toilet flushing). But, food waste, food scraps, industrial food waste, and wood waste can also be used.
• Once it is processed, biogas is exactly the same as fossil-fuel natural gas in terms of molecular structure and can be used as a renewable fuel.
• Digestate is the solid product that results from anaerobic digestion. It is a nutrient-rich fertilizer that is pathogen-free, doesn't smell, and can readily be absorbed by plants. It presents a lower risk of agricultural runoff than other fertilizers and is at least as effective as fossil-based fertilizers.
• There are currently 2,000 operational biogas systems in the United States. Some are in wastewater treatment facilities, some are on farms, some are in landfills, and a few only handle food waste. ABC sees the potential for 13,000 more biogas systems in the United States.
• Those 13,000 new systems would require $40 billion in new capital investment, and create 300,000 construction jobs and more than 20,000 new, permanent long-term operational jobs.
• Biogas protects the air, water, and soil in addition to being profitable; it is a safe and responsible waste management system that has a net positive impact on the environment.
• Whereas renewable energy sources like solar and wind depend on the sun and wind to run, biogas constantly generates electricity and can serve as a source of baseload power. Therefore, biogas can complement more intermittent renewable power generation.
• Biofuels should be given tax breaks, like wind and solar energy are, to help the sector thrive, as they are an efficient, baseload renewable resource.

 

Brian Sievers, Chief Operating Officer, Sievers Family Farms, LLC.

• Sievers and his wife, with the help of their son, installed an anaerobic digestion system on their farm in 2010. It includes anaerobic digesters, effluent storage structures, and separate solid storage structures.
• Anaerobic digestion creates a closed-loop system, which converts waste into resources and improves profitability and efficiency while reducing overall waste.
• The Sievers family farm benefitted from USDA programs, including the Rural Energy for America Program, which provides grants for renewable resources, and the Environmental Policy Incentives Program, which supports farmers in their conservation efforts. These programs helped provide the resources to build the facilities, which cost a total of $12 million.
• The Sievers sell the electricity produced by their biogas system to the local grid, though the price at which the grid buys their electricity is falling, which will result in challenges moving forward. They currently earn 6.4 cents per kilowatt hour, but in 2020 the power purchase agreement they have in place will expire, and the rate after that is uncertain.
• Though they started off just using manure, they now incorporate local food waste, chick hatch waste, meat production and processing waste, and waste from local ethanol and diesel production into their plant. Food waste has brought their production up from around 40 percent capacity to 100 percent capacity.
• They have also started using cover crops in their processing plant. Cover crops are a huge potential feedstock for the biogas industry as they are normally killed with herbicide and go to waste. Instead, the Sievers harvest the cover crop and use it in their digester.
• In addition to selling electricity into the grid, they also sell the digestate that they produce. Sievers sees this as an extra benefit of anaerobic digestion, as the digestates are extremely nutrient rich and can be valuable fertilizers that improve soil health.

 

Chris Peot, Manager, Resource Recovery, D.C. Water

• D.C. wastewater treatment plants takes used DC municipal water, clean it of pollutants (such as carbon and other nutrients), and return clean water back to the environment.
• Every city in America has the potential to have a wastewater treatment facility, as all cities collect and treat water.
• The D.C. Wastewater Treatment Facility refers to itself as a resource recovery facility because the water is cleaned and the solid material left over from the process is returned to the land. Water and nutrients that might have gone to waste end up being responsibly reintroduced to the environment.
• D.C. Water was already a “closed loop” facility, recovering biosolids and returning them to the land, mainly to farms outside the service area, as well as returning water to the river cleaner than it was taken. Now, the use of anaerobic digestion at the plant will allow D.C. Water to re-use these nutrients in the service area, such as in urban farms and landscaping. This will keep the resources local, and save energy on biosolids transportation.
• D.C. Water recently made a $470 million investment in anaerobic digesters. That is a large sum, but the city would have had to invest $120 million in new lime stabilization facilities otherwise. All in all, the investment only has a 12-year pay off. The project was bond funded.
• The capacity of the digesters is large enough to handle the projected waste from the city's population 30 years from now, and the tanks should be functional for more than 70 years.
• “It’s a rare combination of a municipal project that brings economic benefits and makes environmental sense,” said Peot.
• Some of the solids produced end up on farms and some are used in urban gardening projects and to grow urban trees, which in turn bring their own set of environmental benefits including reducing runoff and creating green spaces.
• D.C. water has branded their fertilizer byproduct as “Bloom.” (bloomsoil.com)
• The plant produces 8 to 10 MW of electricity, enough to power 450,000 American homes. It also produces other products like steam that can be used in cooling processes.

 

Clarke Pauley, Vice President, Organics & Biogas Division, CR&R Environmental Services

• CR&R is a privately owned, integrated waste management group in southern California with 3 million residential customers, 50 municipal contracts and about 1,500 employees.
• California’s regulatory frameworks and incentives help empower renewable waste management groups like CR&R. California has been passing legislation that promotes waste management for a while, but it has recently shifted towards recycling organics.
• Bills like SB 1383 and AB 2313 in California provide financial incentives and a framework for organics recycling and biogas to thrive. At the federal level, the Renewable Fuel Standard, which requires transportation fuel to contain a minimum level of renewable fuel, plays a critical role.
• Organic waste represents around 30 percent of what goes into landfills nationwide, so by converting organic waste into products like natural gas and fertilizer, overall waste can be hugely reduced.
• CR&R turns organic waste into fertilizer and renewable natural gas that it uses to run its truck fleet of near-zero emission trucks. Currently, half of its fleet runs on compressed natural gas (CNG).
• Pound for pound, methane has a climate-warming effect that is far greater than CO2's. Burning renewable natural gas (which largely consists of methane) in trucks prevents methane from entering into the atmosphere. CR&R’s CNG trucks have 90 percent lower emissions than traditional diesel trucks.

The United States produces more than 70 million tons of organic waste per year (food waste, manure, agricultural waste, biosolids, etc.), which pose significant risks to air and water quality as well as to human health. These materials are numerous and include both edible and non-edible sources. Even if needless edible food waste is eliminated in all communities, there are numerous sources of non-edible organic wastes, including agricultural wastes, wastewater, and inedible food processing wastes.

According to the U.S. Department of Agriculture, Department of Energy, Environmental Protection Agency, and the American Biogas Coalition, 8,241 dairy and swine farms, 3,888 wastewater treatment facilities, more than 400 landfills and nearly 1,000 stand-alone food waste systems could be producing biogas, RNG and other commercial products from wet wastes.

Not only do anaerobic digester systems manage these 'waste' materials, they create local jobs, improve air and water quality, assist in meeting multi-agency nutrient management strategies, and help to meet multiple policy goals espoused in both the Farm Bill and the Renewable Fuel Standard. State waste resources are diverse and numerous. Briefing attendees had the opportunity to learn about the potential resources in their states, the economic and job opportunities they offer, and important policy drivers for this promising industry.