The comparison between renewable natural gas and natural gas reveals two energy sources headed in different directions. Scientists estimate only 52 years of natural gas reserves remain for extraction. Conventional natural gas powers millions of American homes today, and renewable natural gas (RNG) emerges as a promising alternative.
RNG and conventional natural gas share methane (CH₄) as their main component. Their environmental footprint and origins tell different stories. RNG captures as much CO₂ as it releases, making it carbon-neutral. The production process involves anaerobic digestion of organic materials such as agricultural residues, food waste, and sewage sludge. The limited production and complex processing make RNG more expensive than conventional natural gas. The burning process of RNG produces nitrous oxide, which contributes to smog and degrades air quality.
We will explore these energy sources’ differences and their environmental effects. The discussion will help you understand their potential roles in America’s energy future. Let’s explore what makes each gas unique and how it shapes our energy decisions.
Production and Source Differences
Conventional natural gas and renewable natural gas (RNG) have completely different origin stories. Ancient plant and animal remains buried deep underground formed conventional natural gas over millions of years. RNG comes from organic materials that decomposed through anaerobic digestion.
Companies extract traditional natural gas through drilling. The gas needs minimal processing because it naturally contains over 90% methane. Texas, Pennsylvania, and Louisiana lead production in the United States, which produces almost all the natural gas it uses.
RNG production starts with organic waste from four main sources: municipal solid waste landfills, wastewater treatment plants, livestock farms, and food production facilities. Raw biogas contains only 45-65% methane and 30-50% carbon dioxide. The biogas goes through upgrading processes like water scrubbing, pressure swing adsorption, or membrane separation to remove impurities. These processes increase methane concentration to 95-99% and create pipeline-quality RNG.
This renewable alternative shows great promise. UC Davis research shows that more than 20% of California’s residential natural gas consumption could come from RNG derived from existing organic waste. The United States could produce up to 10 trillion cubic feet of RNG annually by 2030.
Environmental and Health Impacts
The environmental effects of these gas types are completely different. Methane makes up most of both gasses and traps heat 84-87 times more effectively than carbon dioxide over 20 years. So, any leaks during production or distribution add by a lot to climate change.
Regular natural gas extraction and transport harm the environment. Research shows methane leaks from U.S. oil and gas operations are about three times higher than what the government thinks. Gas can match coal’s climate damage with just 0.2% leakage.
RNG helps the environment by catching methane that would leak into the air. Food waste turned into RNG can cut greenhouse gas emissions by 125% compared to regular fuels.
In spite of that, burning either gas pollutes indoor and outdoor air:
- Burning releases nitrogen oxides, carbon monoxide, and particulate matter
- Gas stoves make childhood asthma risk jump – 12.7% of U.S. childhood asthma cases come from gas stove use
- Harvard scientists found 21 dangerous air pollutants in unburned gas, including benzene and toluene
These gasses move through the same leaky pipes, creating similar safety issues and emissions whatever their source.
Performance, Cost, and Infrastructure
These gasses have similar performance characteristics because they mainly contain methane (95-99% for RNG). RNG can use the existing natural gas infrastructure without any changes to pipelines or equipment due to this chemical similarity.
RNG costs a lot more than conventional natural gas right now. Traditional natural gas prices stay around USD 3.67 per MMBTU, while RNG production costs typically range between USD 7.00-20.00 per MMBTU. Limited production scale and processing complexities drive these higher costs.
Carbon pricing makes RNG more economically viable. A carbon price of USD 40.00 per ton could help biogas plants become financially stable. RNG costs should drop as the market matures and production volumes grow.
RNG has compelling advantages in transportation applications. Vehicles using compressed natural gas (CNG) and liquefied natural gas (LNG) can run on either conventional gas or RNG. Monthly rebates through price discounts might be available to fleet operators who use RNG under the federal Renewable Fuel Standard program.
RNG’s greatest strength lies in its infrastructure compatibility. RNG can flow directly into existing natural gas networks once it meets pipeline quality standards, which eliminates the need for separate infrastructure investments.
Comparison Table
| Characteristic | Renewable Natural Gas (RNG) | Conventional Natural Gas |
| Source | Organic waste materials (agricultural residues, food waste, sewage sludge) | Ancient plant and animal remains buried underground |
| Production Method | Anaerobic digestion | Underground extraction through drilling |
| Original Methane Content | 45-65% (raw biogas) | Over 90% |
| Final Methane Content | 95-99% (after processing) | Over 90% |
| Environmental Effect | – Carbon-neutral fuel – Can provide 125% reduction in greenhouse gas emissions when sourced from landfill-diverted food waste | – Limited reserves (52 years remaining) – Methane leakage ~3x higher than government estimates |
| Cost (per MMBTU) | $7.00-20.00 | $3.67 |
| Infrastructure Compatibility | Can use existing natural gas infrastructure | Existing infrastructure |
| Air Quality Effect | – Releases nitrous oxide when burned – Creates smog – Releases nitrogen oxides, carbon monoxide, and particulate matter | – Same combustion emissions as RNG – Contains 21 hazardous air pollutants when unburned |
| Future Potential | Could produce up to 10 trillion cubic feet annually by 2030 | Limited by remaining reserves |
| Processing Requirements | Requires upgrading processes (water scrubbing, pressure swing adsorption, membrane separation) | Minimal processing required |
Conclusion
RNG and conventional natural gas share some features but differ in key ways. RNG stands out because we source it from organic waste materials, making it a carbon-neutral option compared to fossil-based gas. Both fuels work the same way thanks to their high methane content, but their effect on the environment is quite different.
RNG traps methane that would leak into the atmosphere, so it cuts down greenhouse gas emissions by a lot when it comes from waste. Both gasses create the same emissions when burned. RNG’s biggest advantage is that it works with our current infrastructure. This means we can switch to cleaner energy without spending too much on new systems.
Money remains the biggest roadblock to wider RNG use today. Making RNG costs more than regular natural gas, but this gap should shrink as production grows and carbon pricing changes. Regular natural gas will only last another 52 years, which shows why we need eco-friendly alternatives.
Our energy future needs careful planning. RNG shows real promise, especially where electric power isn’t practical. Green Gas Inc helps homes and businesses switch to this cleaner fuel while keeping the same performance. RNG works with existing systems, making it a great stepping stone that helps the environment now and supports future eco-friendly goals.
America’s energy world keeps moving toward cleaner options. RNG deserves a spot in our plan to cut carbon emissions while keeping energy reliable. With smart planning and more investment in production, renewable natural gas can help build a greener energy future for our kids and grandkids.
FAQs
Q1. What are the key differences between renewable natural gas and conventional natural gas?
Renewable natural gas (RNG) is produced from organic waste through anaerobic digestion, while conventional natural gas is extracted from underground fossil fuel reserves. RNG is considered carbon-neutral, whereas conventional natural gas contributes to greenhouse gas emissions. However, both have similar chemical compositions and can use the same infrastructure.
Q2. What are the main drawbacks of using renewable natural gas?
The primary disadvantage of renewable natural gas is its higher production cost compared to conventional natural gas. Additionally, RNG requires more extensive processing to reach pipeline-quality standards. When burned, it still releases pollutants like nitrous oxide, which can contribute to air quality issues.
Q3. How long are the world’s natural gas reserves expected to last?
Current estimates suggest that there are only about 52 years of conventional natural gas reserves remaining for extraction. This limited supply underscores the importance of developing sustainable alternatives like renewable natural gas.
Q4. Is renewable natural gas more environmentally friendly than conventional natural gas?
Yes, renewable natural gas is generally more environmentally friendly. It captures methane that would otherwise escape into the atmosphere and can provide significant reductions in greenhouse gas emissions, especially when sourced from landfill-diverted food waste. However, both types of gas still produce similar emissions when burned.
Q5. How does the cost of renewable natural gas compare to conventional natural gas?
Renewable natural gas is currently more expensive than conventional natural gas. While conventional natural gas prices are around $3.67 per MMBTU, RNG production costs typically range between $7.00-20.00 per MMBTU. However, as production scales up and carbon pricing mechanisms evolve, this cost gap is expected to narrow.
References
- https://www.epa.gov/lmop/renewable-natural-gas
- https://www.earthday.org/greenwashed-gas-a-fossil-fuel-industry-coverup/
- https://news.stanford.edu/stories/2024/03/methane-emissions-major-u-s-oil-gas-operations-higher-government-predictions
- https://rmi.org/reality-check-natural-gas-true-climate-risk/
- https://hsph.harvard.edu/climate-health-c-change/news/natural-gas-used-in-homes-contains-hazardous-air-pollutants/
- https://www.clf.org/blog/the-truth-about-renewable-natural-gas/
- https://sightline.org/2021/03/09/the-four-fatal-flaws-of-renewable-natural-gas/
- https://www.gasfoundation.org/wp-content/uploads/2019/12/AGA_3894-RNG-2-Pager_V-11.pdf
