Renewable Natural Gas: It’s Place in Our Energy Landscape

Renewable Natural Gas Plant

For many, renewable natural gas is a fairly unheard-of energy source. According to a Press Release published by Northwest Gas Association, on March 22, 2018, “Governor Jay Inslee officially signed into law a bill that will encourage the increased production of renewable natural gas (RNG) as an energy source for Washington State”.  So we at Hanging H Companies feel it’s important to get the word out as to what RNG is, how it fits into the energy infrastructure, as well as it’s limitations.

What is Renewable Natural Gas?

Renewable Natural Gas, also known as biomethane, is a gas produced from the breakdown of organic waste matter, such as agricultural waste, manure, sewage, and food waste. With upgraded RNG, the higher purity level is very well suited for high efficiency heating applications, such as burners and boilers, as well as in gas engines like natural gas powered vehicles. The basic fuel component of both fossil natural gas and renewable natural gas is the same: methane, or CH4.

How does RNG fit into the Energy Infrastructure?

Biomethane is mostly produced at landfills, wastewater treatment plants, and some agricultural operations. By connecting these facilities with the existing natural gas pipeline transportation grid, renewable natural gas can be transported to already existing natural gas storage facilities.  This allows the producers of this valuable resource to produce at full capacity without having to burn off excess or invest additional capital in gas storage units or miles of midstream pipelines.

From there, RNG is transported through existing pipeline infrastructure to the consumers. Heating homes with renewables, growing the clean energy vehicle sector, and using green energy for manufacturing happens without any major reworking of the midstream and downstream systems.

What are the limitations of Renewable Natural Gas?

Renewable Natural Gas is not naturally pure enough for high efficiency use.  Most RNG has been in the range of 60% – 70% methane.  While this is well suited for many manufacturing operations, it is not well suited for high efficiency and clean-burn applications, such as for use in vehicles and residences. Recent changes in purification techniques have changed this. According to the International Journal of Chemical Engineering, RNG is upgraded to natural gas quality, containing more than 90% methane.

Upgraded RNG adds extra cost to the processing. This has been a challenge for many facilities, and for the final cost of the upgraded biomethane to be competitively priced.  Several purification methods have been developing, including anaerobic metabolism, fermentation substrates and adsorption materials.  As technology advances, this cost differential is becoming less and less of an obstacle.

RNG in the Real World

RNG is not simply a future technology that is still impractical for the real world.  In the UK, there are over 50 plants already incorporating anaerobic digestion to produce economically feasible upgraded renewable natural gas. In Canada, FortisBC is already mixing RNG with fossil natural gas into the existing gas distribution system, making headway in the path to renewable and sustainable energy.

Closer to home, L’Oréal, the world’s largest cosmetics company, has signed a 15-year agreement to purchase 40% of the RNG produced at Big Run Landfill in Ashland Kentucky. L’Oréal has already dropped it’s carbon emissions by 84%. This was achieved by using solely renewable electricity at all 21 of it’s US manufacturing and distribution plants. L’Oréal’s plan is to achieve carbon neutrality by 2019.  Renewable natural gas plays a significant role in accomplishing this goal.

Renewable Natural Gas in the Future

Currently, renewable Natural Gas production is economical in the United States due to energy credits, assistance to lower the cost of the gas to compete with fossil natural gas. While MSG (municipal solid waste), WWTP (waste water treatment plants), dairy, and landfill are all viable sources of biomethane, it’s landfill that is the leader as of the publishing of this article.  Landfill sites have the lowest cost to produce RNG, and the amount produced can be scaled up significantly from it’s current levels. MSG, WWTP, and dairy all hold potential, but production prices will need to diminish.

Clean energy is an important topic for our time. Fossil natural gas is 50% – 60% cleaner to produce electricity than is coal.  Thanks to technical advancements in fracking, fossil natural gas has also become cheaper than coal energy. The oil and gas industry has been building a solid infrastructure of pipeline and storage facilities. This upstream, midstream, and downstream gas grid built on the shoulders of the fossil fuel era helps to make biomethane more affordable and a bigger part of our renewable energy future.

Hanging H is proud to play a role as an experienced cross-country and municipal pipeline construction company. For more information about our mission, service offerings and projects please visit our contact page and speak with one of our able representatives.

May 14, 2018

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