By HSE East Africa | Tuesday Sep 26, 2017
Works to increase power generation from methane gas in Lake Kivu are scheduled to begin in November 2017 following the signing of a $100 million investment by Highland Group Holdings Ltd. (HGHL).
According to a statement, the agreement will raise the $370m capital required to extract gas that will generate up to 106 megawatts of electricity from the lake.
The project located at Cape Busororo, near Nyamyumba in Western Rwanda is run by Symbion Power Lake Kivu Ltd a subsidiary of the U.S. firm Symbion Power LLC. Symbion acquired the Kibuye Power 1 (KP1) methane gas extraction plant and the associated power generation facilities at Gisenyi in 2016 and later signed 25-year power purchase agreement (PPA) for a 50 Megawatt methane gas to power project with the government of Rwanda.
According to Symbion Energy CEO Paul Hinks, the investment will now make it possible to rehabilitate and expand the existing plant from the current 3.6 MW to produce between 8 to 10 MW by mid-2018 as well as fast track at least 22MW of power within 18 months.
A project run by KivuWatt, a subsidiary of US-based energy corporation ContourGlobal, is already generating 26 MW from methane gas in another part of Lake Kivu.
It is estimated that Lake Kivu contains over 60 billion cubic meters of methane and 300 billion cubic meters of Carbon dioxide accumulated and trapped at significant depth in the lake. The methane could yield anywhere from 160 to 960 megawatts over a period of 50 years, depending on the efficiency of the extraction process and the power conversion technology.
The gas extraction process brings gas-laden waters from 350 meters below the surface at 35 bars to 2 bars of pressure via a gas separator where gas bubbles are extracted from the water. Raw gas is then washed in four wash towers where “wash water” from a depth of 40 meters is mixed with the gas to remove as much of the Carbon dioxide as possible. This water is returned to a depth of 60 meters, shallow enough for some of the carbon dioxide to eventually diffuse into the atmosphere. The end product, a gas composed of roughly 85 percent methane, is then pressurized and sent to a turbine electric power plant onshore.
These two power projects are expected to reduce the risk of gases that are trapped in the deep layers of the lake escaping and rising to the surface which could cause an explosion endangering the communities living around Lake Kivu.
Symbion has previously stated that it is working closely with the government of Rwanda and its regulatory agencies to ensure that its Lake Kivu projects deliver affordable energy in an efficient and environmentally responsible manner.