The path toward a more sustainable future contains a host of renewable options: solar, wind and hydropower, just to name a few. Renewable natural gas (RNG) — biogas processed to meet utility requirements — is interchangeable with conventional natural gas and serves as a sustainable energy source. RNG has the potential to minimize negative environmental impacts and help reduce greenhouse gas emissions.

Many municipalities are turning to cost-effective solutions to produce renewable fuel opportunities. Pursuing these solutions helps municipalities reach sustainable goals, while using common renewable resources. Municipal solid waste landfills, and food waste and wastewater treatment plants, all offer different solutions to generate RNG.

Converting Organics to RNG

There are a variety of organic materials that can be used as part of the RNG conversion process. The U.S. Environmental Protection Agency (EPA) lists landfills as the third-largest source of human-related methane emissions in the U.S.; methane can be processed and transformed into RNG. This type of biogas is often used to power natural gas vehicles or placed in natural gas pipelines for a variety of uses after processed into RNG.

Food waste can also be converted into biogas to produce RNG or compressed natural gas (CNG) through anaerobic digestion. In addition, diverting food waste from landfills provides a positive environmental impact by beneficially reusing the waste. CNG can be used as transportation fuel in place of the gasoline needed to power vehicles. Additionally, biogas produced from wastewater treatment solids can be used to offset facility fuel needs. In the U.S., approximately 1,200 wastewater treatment plants have anaerobic digesters. This means there is a large opportunity to produce RNG using existing municipal facility assets, such as facilities for wastewater treatment and for disposal of solid waste.  

Regulating a Sustainable Future  

U.S. federal and state environmental credits have helped spur further interest in the production of RNG. The U.S. Renewable Fuel Standard (RFS) program and California Low-Carbon Fuel Standard are two policy initiatives providing financial incentives for pursuing the alternative fuel source. The RFS requires transportation fuels that are sold in the U.S. to contain a minimum volume of renewable fuels. This often affects oil refiners, as well as gasoline and diesel importers.

These initiatives have been implemented with the goal of reducing greenhouse gas emissions, while still meeting the demand for transportation fuels. RNG either can be used locally where it is converted, or it can be made pipeline-ready for transport to other areas for use. Such flexibility means RNG can be used across a widespread geographic area.  

The future possibilities for RNG are truly exciting, with the opportunity for energy generation produced from a renewable, sustainable source. Now is the time for municipalities to leverage existing facilities and resources, capitalize on the potential financial benefits, and reduce greenhouse gas emissions through the production and use of RNG.  

 

Environmental projects require a dedicated and knowledgeable team who can implement solutions for any challenge faced. Discover how we're prepared to help you navigate projects with confidence. 

Discover Our Solutions

by
Robert Craggs is national technical services leader for the solid waste and resource recovery group at Burns & McDonnell. He serves as the representative for the Planning and Management Technical Division on the advisory board for the Solid Waste Association of North America (SWANA) and is a board member for the Recycling Association of Minnesota.