Natural Gas Leaks and their Devastating Consequences for the Environment

Application Note11 Jan 2023

When we think of natural gas leaks, we usually think of major damage to natural gas pipelines that leak huge amounts of natural gas into the atmosphere. Yet small leaks are just as harmful to the environment and even more dangerous. They are usually not obvious and therefore often discovered late.

Author: Melanie Wahlers, Technical Marketing Manager, Axetris Switzerland

The officially known natural gas emissions are reported by the respective countries to the International Energy Agency (IEA). Satellite data, however, shows clearly that real emissions are far higher than those officially reported. According to IEA estimates, about 180 billion cubic meters of natural gas escaped from leaks worldwide in 2021. Many of these leaks even spill several tons of natural gas per hour.

Natural gas consists mainly of hydrocarbon compounds, of which methane accounts for the largest share (up to 99%). Compared to carbon dioxide, methane has a global warming potential (GWP) 28 times higher, calculated over a time horizon of 100 years. Due to its climate-damaging potential, methane contributes significantly to global warming. Throughout the entire process, from natural gas extraction and transportation to the consumer, the colorless and odorless natural gas often escapes unnoticed. Especially in populated areas, this can become a danger. The methane contained in natural gas has an explosion limit in air at room temperature of 5 to 15%. Because the methane content in natural gas is very high, its dilution of the natural gas in the outside air quickly leads to an explosive gas mixture.

Natural gas pipelines are often very old and habe been in operation for decades. Environmental influences cause the material and the weld seams to become brittle and permeable over time. Small leaks occur and result in significant unintentional methane emissions.

In addition to significant potential damage to our climate, natural gas emissions have enormous economic impacts. Additionally, suppliers miss out on sales when the product is lost. The sooner leaks are detected, the sooner methane emissions can be stopped. Reliable measurement technology is central to this. Because the natural methane concentration is about 1.8 ppm, the detection limit of the measuring instruments must work reliably in this range. The measuring frequency is also a decisive factor for many applications.

Monitored areas are often patrolled by cars, scooters or drones. Their respective speed requires an equally fast response from the measuring device.

TDLS technology is ideally suited to these requirements as an optical and non-contact measuring method. TDLS stands for "Tunable Diode Laser Spectroscopy". A narrow-band laser beam scans across the absorption lines of the corresponding gases in the infrared spectrum. Due to the narrow bandwidth, the lines can be detected individually. Cross-influence by other gases is thus ruled out.

The LGD Compact-A CH4 laser gas detector offers TDLS technology and an extremely robust design. This eliminates the need for regular calibration or maintenance which makes metrological monitoring for methane leaks attractive for plant operators. The low initial costs of the LGD Compact are quickly compensated for by the methane saved. This benefits both plant operators and our environment and climate.