Reassessing LNG’s Greenhouse Gas Emissions

Liquefied Natural Gas (LNG) has become a significant player in the global energy market, especially with the United States emerging as the largest exporter. However, the environmental impact of LNG, particularly its greenhouse gas (GHG) emissions, is a growing concern. This article breaks down a recent study that aims to provide a more accurate estimate of these emissions by examining the entire supply chain of LNG.

The Importance of Life Cycle Assessments (LCAs)

Life Cycle Assessments (LCAs) are crucial for understanding the environmental impact of products from production to end use. For LNG, this means looking at everything from natural gas extraction to its final use in generating electricity. 

A new study on the topic by Roman-White et al. introduces a new framework for LCAs that offers a more detailed and accurate picture of GHG emissions. The study was published in the American Chemical Society’s Sustainable Chemistry & Engineering Journal.

“Gas Pathing: Improved Greenhouse Gas Emission Estimates of Liquefied Natural Gas Exports through Enhanced Supply Chain Resolution” focuses on refining the accuracy of GHG emission assessments within the LNG industry. The report builds upon Cheniere Energy’s first LCA study, published in 2021.

Key Findings

1.     Improved Gas Pathing Algorithm:

The study developed a gas pathing algorithm that maps out how natural gas is purchased, sold, and transported within the U.S. This algorithm identifies 138 distinct gas pathways, showing that GHG emissions can vary significantly depending on the route taken.

2.     Lower Emissions Estimates:

The reference case GHG intensities for U.S. LNG delivered to Europe are 22-53% lower than previous studies. This suggests that earlier estimates may have overestimated the emissions associated with LNG.

3.     Impact of Measurement Data:

When incorporating recent measurement data, the GHG intensities are found to be 41-52% higher than the reference case, but 20-28% lower than prior estimates employing non-empirical data. This highlights the importance of using up-to-date and accurate data for LCAs.

4.     Variability in Emissions:

The study shows significant variability in emissions between different gas pathways. For example, emissions can vary by nearly a factor of six depending on the specific route and facilities involved.

Methodology

The researchers used data from two U.S. liquefaction facilities and applied their gas pathing algorithm to develop detailed emissions profiles. They considered various stages of the supply chain, including production, processing, transmission, liquefaction, and shipping.

Implications

The findings of this study have several important implications:

• Policy and Regulation: Accurate emissions data are essential for developing effective policies and regulations to reduce GHG emissions.
• Industry Practices: The gas industry can use these insights to optimize their supply chains and reduce their environmental impact.
• Consumer Awareness: Better information on the environmental impact of LNG can help consumers make more informed choices.

Discussion

The new study offers a nuanced view of greenhouse gas (GHG) emissions associated with liquefied natural gas (LNG), showing notable variability in emissions based on specific supply chain pathways. This perspective contrasts with the claims discussed in a Forbes article by energy analyst Robert Rapier, titled Is Natural Gas Dirtier Than Coal? In that article, Rapier examines assertions by researchers that LNG could carry a higher emissions footprint than coal.

The detailed life cycle assessments (LCAs) presented in the Roman-White study reveal that LNG emissions may be lower than previously estimated when accounting for specific pathways and recent data. These findings underscore the importance of granular, supply chain-specific information for accurate environmental comparisons, aligning well with the questions raised in Rapier’s Forbes article.

Conclusion

This study by Roman-White et al. represents a significant step forward in understanding the GHG emissions associated with LNG. By providing a more detailed and accurate picture of these emissions, it helps pave the way for more sustainable practices in the natural gas industry.

Stay Current on the Future of Energy

Reporting on all things energy, we keep our readers ahead of the curve on the latest developments changing the landscape. Subscribe to Shale Magazine to keep current on energy news, sustainability leaps, and economic intelligence.

When you’re on the go, check out our critically acclaimed podcast, The Energy Mixx Radio Show where we feature the latest insights from top leaders in the energy industry.