How Engineers Are Harvesting Methane From A Rwanda Based Lake That Is Almost On The Edge Of Explosion?

Rwandan President, Paul Kagane, this week inaugurated a power plant worth 26-megawatt that will mainly work for extracting methane from Lake Kivu. It is one of the first gas water extraction power units on this planet and it will work to provide electricity to whole nation. This power producing unit will be connected with an offshore located barge that has been located over Lake Kivu. It is one of the most famous water bodies located somewhere between Democratic Republic of Congo and Rwanda. Being called as one of the first “killer” water bodies in the world, this one is explosive on account of excessive accumulation of methane and CO2 in and around it.

 

This lake has a surface area of around 2, 700 kilometers and it is estimated that it is filled with somewhere around 300 billion cubic meters of carbon dioxide that is thoroughly mixed in its water. This kind of enormous concentration of gas dissolution in the water is result of two prime phenomena. The first process can be associated with the Great Rift Valley, here East Africa is getting pulled apart because of tectonic forces. Researchers and scientists believe that it has led to high end volcanic activity which has led to release of carbon dioxide in excessive amounts from lake’s bottom.

 

The next reason is presence of a bacteria in Lake Kivu that is rapidly converting the dissolved CO2 into methane. The lake is infested by two types of bacteria mainly that are too dedicated towards production of methane gas by break down of organic matter. But, the problem wouldn’t be this intense if methane and CO2 would escape the atmosphere. The condition has worsened in light of the fact that the lake also has very intense layers of mineral-lad water which are located way beneath the surface located fresh water. It leads to permanent stratifications that prevents the vertical mixing of water inside the lake and leads to trapping of gases close to bottom.

 

The lake seems very harmless from top, however, it is on brink of limnic eruption. In case, the lake undergoes a disturbance like landslide or rock falling, it will start a dangerous chain reaction which would lead to release of gases in an enormous manner. The same thing happened with two other lakes previously, the first one was in 1986 with Lake Nyos that was situated in Cameroon which released a plume of CO2 making its volume rise to 0.3 to 1 cubic kilometer around the lake. However, because it was much denser than air, it remained close to ground and travelled rapidly from here to there. It killed more than 1, 700 people near the lake because of asphyxiation. Monoun, also located in Cameroon, had a similar explosion almost two years back and lead to killing of 37 people in a limnic eruption.