An Introduction to Renewable Natural Gas

Renewable natural gas (RNG) is a renewable energy source that, when used, can reduce methane emissions, and provide
other environmental benefits. Derived from organic waste matter, RNG can be used as a substitute for natural gas and has many
end uses. This factsheet provides general background information on RNG and links to other EPA RNG-related resources.

What is RNG?

•	EPA's methane partnership programs define RNG as
anaerobically generated biogas that has been refined for use in
place of fossil natural gas.

•	The biogas used to produce RNG can be sourced from
municipal solid waste (MSW) landfills, wastewater treatment
plants, stand-alone organic waste management operations,
and livestock manure management systems.

How is RNG made?

•	Raw biogas has between 45 and 65 percent methane and a
small amount of carbon dioxide, among other compounds;
RNG has a methane content of 90 percent or greater.

•	To produce RNG, raw biogas must go through a series of steps
to remove carbon dioxide, water, and other trace chemicals.

•	The level of refinement depends on use - RNG for pipelines
and vehicles needs more refinement than RNG for thermal and
electricity uses.

Options for RNG Delivery

The two main methods for delivering RNG to end users are injection into a pipeline or using the gas on site or locally.

Pipeline Injection1 (-40% of projects in the United States)

•	RNG projects inject the product into a fossil natural gas
pipeline, either a transmission or distribution pipeline.

•	There are two components to a pipeline interconnection
facility:

1.	Point of receipt:

» Monitors gas quality to ensure it meets specifications
» Prevents non-compliant gas from entering the

pipeline network
» Meters and odorizes the volume of RNG put into the
pipeline network

2.	Pipeline extension:

» Transfers the RNG from the point of receipt to the
nearest available natural gas pipeline

•	If pipeline connections do not exist, the RNG project will
need to construct a pipeline extension.

On-site or Local Applications (-60% of projects in the United States)
• Vehicle fuel
» Use of compressed natural gas (CNG) for on-site fleet
vehicles requires less upgrading (no need to meet RNG
pipeline specifications) and avoids interconnection and
transport costs.

Thermal applications
» Use of RNG can offset fossil fuel-based thermal energy
(e.g., natural gas or distillate oil), resulting in anywhere from
40 to 100 percent decrease in greenhouse gas emissions,
reducing flaring or on-site combustion which reduces criteria
pollutant emissions and improves air quality.2
Virtual pipeline
» In a virtual pipeline, RNG is compressed at the point
of generation then transported by truck to the point of
injection or the site where it will be used.

» At the destination, the RNG is decompressed to the

pressure required by the receiving facility.

» A virtual pipeline can be convenient for projects where
an RNG plant is not close to end users, such as remote
landfills, farms, and other biogas sources

Options for RNG Use

VEHICLE FUEL.

RNG can be used as compressed
natural gas (CNG) or liquefied natural
gas (LNG), in different vehicle types.

„ ELECTRICITY
- PRODUCTION.

RNG can be used to
generate electricity.

THERMAL APPLICATIONS.

RNG can be used in direct
thermal applications such as
boilers, greenhouses, and kilns.


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An Introduction to Renewable Natural Gas

Benefits of a Well-Run RNG Project3

Greater Fuel Diversity and Availability

» Biogas feedstocks are generated continuously from a

variety of sources.

» RNG diversifies domestic energy production from more
sources in case of national emergencies or energy shortages.

Local Economic Impacts

» RNG leads to more sales of CNG- or LNG-powered vehicles
in the area.

» Studies have found that California RNG production facilities
could generate 8.5 to 11.2 jobs per million diesel gallon
equivalent compared to petroleum refineries that generate
1.6 jobs per million diesel gallon equivalent.4

Local Air Quality Improvements

» Local air quality can be improved when replacing older,
heavy-duty diesel vehicles with CNG vehicles that emit less
nitrogen oxide and particulate matter.

Reduced Greenhouse Gas Emissions

» RNG-based vehicles yield greenhouse gas reductions of up

to 75 percent compared to gasoline and diesel vehicles.
» Landfill Gas (LFG)-to-CNG projects are relatively less
carbon-intensive than fossil fuel-derived diesel projects.

RNG Operation Best Practices

•	Minimize methane leaks from the RNG upgrading process
using leak detection technology utilizing automated leak
detection systems that notify the operator automatically when
a leak occurs.

•	Properly operate and maintain upgrading equipment.

•	Use renewable electricity to power upgrading equipment
wherever possible.

•	Minimize the distance between the point of generation and the
point of injection or end use wherever practicable.

•	Use best practices for leak detection and minimizing leaks
along the delivery route.

Considerations for Project Feasibility
and Potential for Growth

•	Landfills are potential sources of biogas that can be recovered
and used for energy, but LFG contains a high percentage of
nitrogen that is expensive to remove.

•	Under conditions of low natural gas prices, the cost of biogas
collection and gas cleanup is relatively expensive, making RNG
project economics more challenging.

•	RNG pipelines across the United States have different quality
specifications and are not standardized, leading to less clarity
and certainty for RNG providers.

RNG Projects in the United States5

•	As of 2022, more than 173 RNG projects are operating across
31 states and approximately 40 more are under construction.

•	In the United States, more than 45 percent of operating RNG
projects use landfill gas. About 55 percent of U.S. RNG projects
are from anaerobic digester systems (manure management
systems and food waste).

Policies and Incentives

•	Depending on the source of the RNG and how it is documented,
it could be eligible for EPA's Renewable Fuels Program, which
mandates the incorporation of renewable fuels into the nation's
fuel supply and provides financial incentives.

•	Some states have renewable portfolio standards with renewable
energy certificates that provide financial incentives for RNG
derived from biogas.6

•	California and Oregon have low carbon fuel standards that set
carbon intensity targets each state must meet each year; these
targets can be met by producing or using RNG.7

•	California has a policy requiring the state to implement at
least five dairy-based RNG projects and has made $40 million
available to offset pipeline interconnection costs.

•	A Washington state law established a voluntary program with tax
incentives and tools and began the process of developing state
standards for RNG injection and policy recommendations for
RNG promotion.8

EPA RNG Resources

•	AaSTAR provides information and tools about the use of biogas
recovery systems to reduce methane emissions from livestock
waste.

•	The Landfill Methane Outreach Program (LMOP) works with
industry stakeholders and waste officials to reduce or avoid
methane emissions from landfills.

•	The Natural Gas STAR and Methane Challenge programs allow
partner companies with U.S. oil and gas_operations to document
their voluntary activities to reduce methane emissions from their
operations, including RNG operations.

•	The EPA website has an interactive RNG project map that shows
biogas projects across the United States.

1	U.S. Environmental Protection Agency. January 2021. An
Overview of Renewable Natural Gas from Biogas. Accessed
June 23, 2022. https://www.epa.gov/sites/default/files/2021-02/
documents/lmop rno document.pdf.

2	Ibid.

3	Ibid.

4	ICF. May 2017. Economic Impacts of Deploying Low NOX
Trucks Fueled by Renewable Natural Gas. Accessed
June 23, 2022. https://www.masstransitmag.com/home/
document/12330911/economic-impacts-of-deplovino-low-nox-
trucksfueled-bv-renewable-natural-gas.

5	U.S. EPA. 2022. "RNG Project Map" Accessed April 15, 2022.
Accessed June 23, 2022. https://www.epa.gov/lmop/renewable-
natural-gas#rngmap.

6	National Conference of State Legislatures. April 2020. State
Renewable Portfolio Standards and Goals. Accessed June 23,
2023. https://www.ncsl.org/research/energv/renewable-portfolio-
standards.aspx.

7	California Low Carbon Fuel Standard, California Code of
Regulations, Title 17, Sections 95480-95489; 95491-95497.
Accessed June 23, 2022. https://www.arb.ca.gov/regact/2015/
Icfs2015/lcfsfinalregorder.pdf.

8	Washington State Legislature. Bill Information: HB 2580 -
2017-18. Accessed June 23, 2022. https://app.leg.wa.gov/
billsummarv?BillNumber=2580&Year=2017.


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