RENEWABLE NATURAL GAS (RNG) FOR TRANSPORTATION Frequently Asked Questions BASICS from restaurants, institutions, and What is RNG? industrial food processors that is not BENEFITS OF RNG delivered to biogas digesters or RNG (renewable natural gas) is a key composted usually goes to landfills emerging fuel derived from waste. Converts waste to a valuable where it, too, can release methane and product As organic waste decomposes, it CO2 into the atmosphere. releases a biogas that is 40% to 60% Reduces GHG emissions How is RNG used? RNG can be used methane (CH4). This biogas can be wherever pipeline-supplied NG is used, Produces domestic, renewable captured and refined to remove including as transportation fuel and to fuel from plentiful feedstocks contaminants and increase its heat generate electricity. content. The resulting gas, RNG, can Reduces odor and runoff be used in place of or mingled with Who currently uses RNG? RNG is Creates jobs geologic or fossil natural gas (NG) in used primarily as a transportation fuel pipelines, fueling stations, and storage in NG vehicles. Enhances fuel diversity tanks, or as a “drop-in” fuel requiring no What types of vehicles/engines can Provides a steady supply of engine modifications in NG vehicles. run on RNG? Any engine that renewable energy What’s the difference between operates on NG can run on RNG. Supports organizations’ and biogas, biomethane, and RNG? fleets’ sustainability goals What infrastructure is needed to Biogas is the raw gas produced by the transport and dispense RNG? Uses existing technologies and breakdown of organic materials in an Infrastructure for transporting and natural gas infrastructure oxygen-free (anaerobic) environment. dispensing NG can be used for RNG. After removal of contaminants and RNG is a “drop-in” fuel for NG vehicles. other gases, biogas becomes RNG, Produces domestic, renewable fuel which is typically 90%+ methane. from plentiful feedstocks. According Biomethane is another name for RNG. BENEFITS to the U.S. Environmental Protection Converts waste to a valuable Agency (EPA), the U.S. generated What happens to biogas that’s not 267.8 million tons of municipal solid converted to RNG? product. RNG extracts value from decomposing waste, which can be waste in 2017 (or 4.51 pounds per It depends on the source. On farms, used by the producer in a closed-loop person per day), more than half of animal waste is often allowed to process or sold. Even the byproducts of which (139 million tons) was landfilled. decompose in pits or ponds, where it RNG processing—nutrient-rich solids The remainder was either recycled, produces methane. This methane, a and liquids—have value as a fertilizer. composted, or combusted for energy powerful greenhouse gas (GHG) with recovery. Food waste accounted for the 25 times the global warming potential Reduces GHG emissions. On a largest share (~22%) of tonnage sent to of carbon dioxide (CO2), is often lifecycle basis, RNG can reduce GHG landfills (EPA undated). According to released to the atmosphere. emissions by 95% as compared to the U.S. Department of Agriculture diesel, giving it a nearly net zero At landfills and water resource recovery (USDA), animals at feeding carbon impact. In cases where biogas facilities (WRRFs), biogas is produced operations—including feedlots and would otherwise be released to the from the breakdown of organic waste other confinement facilities—produce atmosphere (e.g., open lagoons), RNG and typically “flared” to convert its 335 million tons of manure (dry weight) can have a negative carbon impact. methane content to CO2, which annually in the U.S. (USDA undated). reduces (but does not eliminate) its global warming potential. Food waste RNG FOR TRANSPORTATION: FREQUENTLY ASKED QUESTIONS Reduces odor and runoff. Compared • NG providers/utilities can gain a as well as contaminants. Landfills are a with uncovered manure storage, RNG renewable fuel supply to not only major source of raw biogas. usually eliminates odors. For farm and reduce their system-wide carbon Before it can become usable RNG, the livestock operations, anaerobic content, but also provide customers biogas produced through anaerobic digestion can also reduce nitrogen and with a voluntary, renewable fuel option. digestion must be upgraded and phosphorus runoff to groundwater and • Fleets/vehicle operators can gain a conditioned. First, hydrogen sulfide and downstream waters. drop-in renewable fuel for their NG water are removed. Then, CO2 is Creates jobs. RNG production can vehicles as well as an attractive removed via chemical, pressure, or create technical and support jobs in the renewable alternative to diesel fuel for membrane processes. development and operation of digesters potential conversions. For transportation use, the resulting and associated equipment. • Communities can improve the RNG can be compressed to make Enhances fuel diversity. RNG can be sustainability of waste disposal and renewable CNG or super-cooled to made from various feedstocks that are vehicular fuel use, thereby enabling a make renewable liquefied NG (LNG). in common supply. Unlike petroleum, circular economy. What are the sources of RNG RNG price is not tied to uncertain or supply? volatile fuel markets. Most U.S. projects are at landfills, but Provides a steady supply of the number of projects associated with renewable energy. Unlike wind or livestock operations and waste water is solar power, weather and climate growing. Food manufacturers and conditions do not affect RNG wholesalers, supermarkets, production. restaurants, campuses, and hospitals Supports organizations’ and fleets’ are also potential sources for RNG. sustainability goals. Compared to Landfills Landfills account for more conventional gasoline and diesel, RNG than 75% of RNG production potential can reduce GHG emissions by 95%. while accounting for 56% of currently Uses existing technologies and operational RNG projects (ANL 2020). infrastructure. Biogas can be Livestock operations Animal manure RNG can be produced and used in a closed- upgraded to RNG with existing cleanup can be collected on a single large farm technologies, transported in existing loop process. Biogas systems use anaerobic or combined from several “cluster” NG pipelines, compressed and digestion to recycle organic waste, turning it into energy and liquid and solid coproducts farms and delivered to a single dispensed at existing compressed NG valuable in agriculture. anaerobic digester for RNG production. (CNG) stations, and used in If manure is stored in open lagoons that conventional CNG vehicles. RNG PRODUCTION AND emit methane, moving it to enclosed SUPPLY digesters prevents those emissions. The RNG produced also displaces WHO CAN BENEFIT FROM RNG? How is RNG made? fossil NG that would have been • Waste generators (e.g., livestock RNG is made from decomposing consumed by NG vehicles, thereby operators, food processers and organic matter. In the U.S., it is most reducing CO2 emissions. Avoided wholesalers, supermarkets, campuses, commonly produced through anaerobic methane emissions and displaced restaurants, hospitals) can gain a (oxygen-free) digestion. The RNG fossil CO2 emissions can produce large sustainable outlet for their waste and feedstock—wastewater sludge, animal reductions in carbon intensity. may be able to turn disposal costs into manure, or food waste—is placed in a Water resource recovery facilities revenue opportunities. closed, oxygen-free tank where micro- Approximately 7% of the U.S.’s organisms break it down into a gas. • Landfills and WRRFs can gain a 16,000+ wastewater treatment plants The resulting biogas is primarily revenue stream as well as potential use anaerobic digestion to produce methane and CO2. cost savings from heat and/or power biogas, most of which is flared or used generation. Because a lot of organic matter (e.g., to heat the digester and onsite facilities • CNG project developers and food waste, paper, textiles) ends up in or generate power. Only 14 WRRFS equipment builders, owners, and landfills, landfills themselves act as currently produce RNG that can be operators can see new business. digesters, producing landfill gas (LFG). used for transportation (WEF 2018). LFG is composed of methane and CO2, November 2020 RNG FOR TRANSPORTATION: FREQUENTLY ASKED QUESTIONS Some RNG pathways have very low carbon intensity (CI) scores because they capture emissions that would otherwise be released to the atmosphere. For farms with manure lagoons that currently emit high levels of methane, RNG production can yield negative CI scores. Diagonal lines in bars represent the range of carbon intensity scores that can be achieved with corresponding RNG projects. (CA = California; CNG = compressed natural gas; CO2e = carbon dioxide equivalent; g = gram; LFG = landfill gas; MJ = megajoule; RD = renewable diesel; WRRF = water resource recovery facility.) (ANL GREET) Other biomass sources RNG can be projects tend to be concentrated where Investors, equipment suppliers, and produced from crop residues and livestock support large industries—the developers Demand for RNG is energy crops through thermochemical dairy industry in California, New York, growing, and RNG production requires conversion, co-digestion, and dry and Wisconsin; the pork industry in a wide range of equipment to process, fermentation. These technologies are Iowa, Missouri, and North Carolina; and store, and transport the fuel. Producing, used in Europe, but have had limited the poultry industry in Delaware and installing, and