Lake Kivu, located between Rwanda and the Democratic Republic of Congo, is home to vast reserves of methane gas, a byproduct of centuries of volcanic activity and organic decomposition.
The nearby Nyiragongo and Nyamuragira volcanoes emit carbon dioxide, which, along with decomposing organic matter, is converted into methane by microbes in the lake’s unique environment. This has led to a concentration of gases unlike anywhere else.
Safety and Power
Lake Kivu’s methane extraction brings various advantages. This process reduces the danger of gas eruptions, which have been fatal in other lakes like Monoun and Nyos in Cameroon, and the extracted methane serves as a clean and effective electricity source.
Considering that in June 2024, only 72% of Rwandans have access to electricity, initiatives such as the KivuWatt power plant aim to increase electrification rates, with this project adding 56 MW to the national grid.
The methane is extracted from the lake’s deep “resource zone.” Pipes transport deep water to a floating platform where pressure changes cause the gases to separate. The methane is pumped to shore, purified and sent to generators.
This process follows strict safety protocols to avoid disturbing the lake’s ecosystem by preventing the release of nutrient-rich deep water.
While beneficial, methane extraction must be carefully managed to manage risks. Disturbing the lake’s layers can increase the risk of gas eruptions, and releasing nutrient-rich water could harm the ecosystem.
Twofold Solutions
Leon van Niekerk, a Sales Engineer at VEGA, provided innovative solutions for this project using the VEGABAR 82 and VEGAFLEX 81 instruments.
These devices were placed in specialised bypass chambers to remain sealed and functional underwater at 20 meters. These sensors provide a reliable and precise solution for measuring differential pressure, ensuring the accurate transmission of data over long distances.
The VEGABAR 82 is designed for high-precision pressure measurements in challenging environments, and its durability and accuracy are crucial for monitoring gas levels and ensuring safe extraction processes in Lake Kivu.
The VEGAFLEX 81 guided wave radar technology sensor provides precise level measurements, and the placement allows for continuous, accurate monitoring, which is critical for maintaining safe operations in the lake’s harsh environment.
The deployment of VEGA technology marked the first successful application of underwater differential and interface level measurement for methane extraction. Accurate measurements ensured the prevention of gas eruptions, safeguarding both the environment and the plant’s operations, showcasing VEGA’s expertise and reliability in handling complex industrial challenges.
Miguel Petersen
VEGA Instruments (Pty) Ltd
Tel. +27 11 795 3249
miguel.petersen@vega.com
www.vega.com
