Renewable natural gas (RNG) is a term used for biogas that has been processed and conditioned for use in place of natural gas produced by oil and gas wells. Biogas results from the decomposition of organic matter under anaerobic (no free oxygen) conditions.
Sources of biogas used to produce RNG includes municipal solid waste landfills, wastewater treatment plants digesters, livestock farms, food production facilities and organic waste management operations. Biogas must be treated so that it meets the specifications required for RNG.
Depending on the amount of treatment used for the biogas, RNG will have a methane content of 45 to 65 percent and a BTU/scf range of about 500 to 1000.
Use of RNG as a fuel reduces the amount of methane that might be emitted to the atmosphere from biogas sources.
Read the Cimarron blog titled “Landfills & Methane” for a more detailed discussion of landfill gas (LFG) treatment, emissions controls, and characteristics.
Sources of RNG
Sources of RNG include:
- Livestock manure
- Crop residuals
- Food and beverage waste
- Wastewater biosolids from treatment plants
- Compost from gardens and lawn clippings
RNG Production from Biogas
The major source of biogas is gas produced by anaerobic digestion of organic material. The biogas can be generated from anaerobic digestion of organic matter in landfills or can be generated in dedicated anaerobic digesters (e.g., sludge from wastewater treatment facilities).
Biogas must be treated before it can be used as RNG. Treatment includes removal of moisture, carbon dioxide (CO2) and trace level contaminants (including siloxanes, volatile organic compounds, or VOCs, and hydrogen sulfide), as well as reducing the nitrogen and oxygen content.
Once upgraded, the gas has a methane content of 90 percent or greater. Typically, RNG injected into a natural gas pipeline has a methane content between 96 and 98 percent.
Processing typically can occur at the generation site which reduces GHG emissions associated with transporting raw materials to a processing facility.
Source: Figure 2.5. Energy Generation Options from AD/Biogas Systems, AgSTAR Project Development Handbook, EPA 430-B-20-001, 3rd Edition.
RNG can be used locally at a facility where the gas is generated, or it can be compressed and sent to a natural gas transmission or distribution pipeline.
As a substitute for natural gas, RNG has many uses. These include:
- Fuel gas
- Generate heat
- Generate electricity
- Vehicle fuel
RNG and Carbon Offsets
RNG can be used to generate carbon offsets. These offsets can be used by companies to meet their sustainability goals and net zero commitments. Most companies choose to purchase verified emission reductions (VER) for use as a carbon offset. A VER is a carbon offset developed under voluntary market standards that operate on a national or international level. VERs are a reduction in GHG emissions from a project that is independently verified using a third-party certification standard.
One carbon offset is equivalent to removing one metric ton of CO2e from the atmosphere.
VER developers comply with standards that include procedures required by organizations to develop and certify carbon credits for voluntary and compliance markets.
Some private Standards organizations include:
Depending on the type of GHG emission reduction project, the price of VERs on the retail market varies from $10 to $30+ per credit.
Renewable Natural Gas (RNG) Certificates are another method of offsetting GHG emissions. Companies can purchase RNG Certificates without changing their existing energy purchase agreements.
Summary and Conclusions
Renewable natural gas (RNG) is a biogas that is generated by the decomposition of organic material. The major sources of RNG include landfills, wastewater treatment facilities, livestock operations and food waste management systems. The RNG must be processed to remove impurities. The treated RNG will typically contain about 45 to 65 percent and a BTU/scf range of about 500 to 1000. This gas can be used as a fuel that replaces natural gas produced by oil and gas operations.
RNG used as a beneficial fuel can generate carbon offsets. Companies seeking to reduce their GHG emissions are funding RNG projects to ensure a supply of verified carbon offsets.
Cimarron – Who We Are
Cimarron’s overall goal is to reduce greenhouse gas emissions for all industries as we work with our clients to create a cleaner environment.
The company engineers and manufactures environmental, production and process equipment for the upstream, midstream and downstream energy industries, as well as environmental control solutions for biogas at wastewater facilities, digester tanks and landfills.
Our flares and ECDs meet all federal and state environmental regulatory requirements for control efficiency and destruction efficiency.
Cimarron offers our customers the know-how and environmental expertise to meet the environmental standards of today and tomorrow. Cimarron is committed to bring value to the Energy industry and their shareholders based on our financial strength, experienced personnel, and engineering capabilities.
As a company, we thrive every day to make a difference through innovation (e.g. ESG), customer focus, and operational efficiency. In addition to being present in all major regions in the US, Cimarron serves more than 45 countries around the world, ranging from offshore to desert. From key operational centers in the United States, Italy and the United Arab Emirates, Cimarron offers ongoing service and support through its own field service personnel and strategic third-party partners, creating a cleaner environment for our customers and their shareholders.
Since its founding in the mid-1970’s in Oklahoma, the company’s product offering has expanded from production equipment to include the largest line of environmental solutions that capture or incinerate fugitive vapors. With the acquisitions of HY-BON/EDI in 2019 and AEREON (including Jordan Technologies) in 2020, Cimarron has added strong brands, products, and services to its portfolio.
Please contact us to learn more about our products and services and about all our ESG solutions at email@example.com or visit our website www.cimarron.com.