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- Methane emissions in the Lake Kivu, Central Africa
Methane emissions in the Lake Kivu, Central Africa
Democratic Republic of the Congo
last update:
4 months agoProblems
Environmental hazards in Lake Kivu
Kivu is a large lake in central Africa. It is located on a tectonic fault line called the East African Rift Valley, making it one of the 10 deepest lakes in the world. It is also the site of active geological processes associated with the faulting of the earth's crust, such as volcanic eruptions and earthquakes. The shores of Lake Kivu in Africa are home to about 2 million people. Every day these people swim in the hot springs and have no idea that at any moment their picturesque body of water can turn into a real monster and destroy everything within a radius of several kilometers. The main danger comes from the huge reserves of volcanic gases accumulated in the lake. According to studies, about 65 cubic kilometers of methane and 256 cubic kilometers of carbon dioxide are hidden at the bottom of the lake, which together can cause a global disaster.
Causes of methane gas formation in Kivu
Due to the high temperature and humidity of the atmosphere above the lake, a kind of stable "cushion" of hot water vapor forms between the water and the air, which suspends the circulation of water molecules. As a result, the liquid does not circulate in the lake and the gas accumulated at the bottom does not dissolve. Lake Kivu is naturally fed by warm underwater springs that burst to the surface through a layer of solidified volcanic lava and sedimentary ash. From time to time the temperature of these springs changes under the influence of volcanic activity and climatic fluctuations, but this does not affect the overall picture. Under conditions of such stability, the gas accumulating under water is deposited in the form of a compressed layer. The pressure holding it back is also kept at the same level, but any disturbance of the equilibrium will lead to an explosion of the accumulated mixture of methane and carbon dioxide.
Difficulties in finding solutions to problems
Doctor of Geological Sciences Boris Nerodov says: "The very fact of formation at the bottom of the lake of a layer of the gas mixture is not something unusual - similar formations are found in many lakes with obvious volcanic origin. However, there is no such concentrated "stuffing" as in Lake Kivu. The main question is not even how it happened - the reasons are clear and natural. Human intervention in ecology in this case is not so significant. It is more important to find a solution to this problem, to invent a way to reduce the concentration of gas in the water and divert the explosive surplus". The scientist notes that this task is challenging because a violation of the balance of pressure between the gas deposits and the water column can serve as a signal for detonation. As a consequence, peculiar columns of methane and carbon dioxide will form, which will reach the surface of the lake, and this dangerous mixture will start to erupt from them. Even if an explosion can be avoided, the release of such a huge amount of chemicals cannot but affect the environmental situation throughout the region. And that makes it even more challenging to find a way to rid Lake Kivu of its explosive contents.
Gallery
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Timelines
2023
January
Democratic Republic of Congo (DRC) oil minister Didier Budimbu Ntubuanga has awarded three licenses to extract methane trapped at the bottom of the 480m deep Lake Kivu – which lies on the border between the DRC and Rwanda. New-York based Symbion Power – the original developer of two out of the three existing Rwanda-based biogas projects taking place in Kivu – says it will use its license to build a 60 MW gas-to-electricity project at a cost of at least $300m, according to CEO Paul Hinks. Electricity from the new DRC project will be distributed to Goma, the capital of DRC’s North Kivu province, by the Congolese company Socodee. The project, called MyHydro, is expected to unlock at least 150 MW of hydropower and will start with the installation of four turbines in the Lubi River, near Mbuji-Mayi in Kasai Province. The license for the two other gas blocks on the lake was awarded to Winds Exploration and Production LLC of the US and Canada-based Alfajiri Energy. The lake is estimated to hold enough methane to produce 700MW of electricity over more than 50 years, but only a fraction is currently exploited on the Rwandan side. Extraction comes with environmental concerns. The degassed water, which is then returned to the lake, contains high levels of nutrients and toxic hydrogen sulfite, which could kill fish and lead to harmful algal blooms, potentially threatening the local fishing industry. “Diluting the resource layer with degassed water might lower gas concentrations enough that commercial extraction would no longer be possible,” says science journalist Nicola Jones in a paper for Nature. None of the preferred bidders for the exploitation of the DRC part of the lake has yet to disclose their modes of operation.
2022
December
The company Symbion Power is now increasingly investing in the DRC energy system. At the US-Africa Business Forum, the company announced a partnership with California-based hydropower developer Natel Energy to install hydro turbines in the first of 33 potential projects in DRC.
2021
September 24
Canadian engineer Philip Morkel, who is the founder of the energy company Hydragas Energy, has developed with his team a project to remove and use gas from the bottom of Lake Kivu. The team is currently seeking funding for the project. Morkel believes that effectively pumping 90 percent of the methane from the bottom of Lake Kivu over the next 50 years would already reduce the risk of limnological disaster by 90 percent in the first 10 years. However, so far this assumption remains theoretical and is not confirmed by relevant studies.
2016
May 19
Rwanda has opened the world's first power plant that runs on methane extracted from Lake Kivu, which has been poisoned by the gas. The opening of the power plant, which runs on methane extracted from the lake, will reduce the likelihood of the second release of poisonous gas. The KivuWatt project began in 2014, with U.S. contractor ContourGlobal as the contractor. The system of methane extraction at Lake Kivu has a difference from the usual drilling - here it is obtained by vacuuming methane and carbon dioxide directly from the lake. At the moment the Americans are working on three more extraction blocks, which are planned to be installed by 2019. When the project is completed, more than 70% of Rwandans will have access to electricity. For a poor country, a methane power plant is a godsend that will save money as well as reduce the percentage of traditionally used "dirty" fuel on which most of the country's power plants run.
2015
July 03
Symbion Power Lake Kivu Limited was awarded a Concession and Power Producing Agreement (PPA) to produce 50 MW of power using Lake Kivu methane. Symbion Power has purchased another concession for a further 25 MW and is currently negotiating a PPA with the Rwanda Electricity Group which may see 8 MW of power despatched to the Grid six months after the PPA has been signed.
2011
May 05
ContourGlobal, a UK-based energy company focused on emerging markets, secured project financing to initiate a large-scale methane extraction project. The project is run through a local Rwandan entity called KivuWatt, using an offshore barge platform to extract, separate, and clean the gasses obtained from the lake bed before pumping purified methane via an underwater pipeline to on-shore gas engines. Stage one of the project, powering three "gensets " along the lake shore and supplying 26 MW of electricity to the local grid, has since been completed. The next phase aims to deploy nine additional gensets at 75 MW to create a total capacity of 101 MW.