Kivu lakeMethane
Gas Extraction
Putting methane
to work
Natural hazards


Project Manager : Minister of Energy, Water and Natural resources, republic of Rwanda

Financing : Contract 2002/035/UE/MS : European Union Delegation at Kigali

Contract holder : 'Data Environnement' Company, F-73000 Chambéry le Haut.

In order to confirm the working hypotheses provided by our computer generated calculations of diphasic flow in the case of a mixture of carbon and methane gas, an experimental field trip took place from mid-November to mid-December on Lake Kiva.

Gas flow curves by depth

Water flow curves by depth

Curves of the fraction of CH4 by depth

Two important results were highlighted by the experiments made during this trip :

Firstly, all flow measurements confirm the validity of the computer generated calculations of diphasic flow. This confirmation allows for the extrapolation of the calculations to an industrial usage many times greater than what was achieved here.

Secondly, the (unexpected) discovery of an enrichment in methane according to depth, which clearly parts company from the law forcast by models of equilibrium, has important consequences for the design of future systems of methane extraction.

The fact that the gas escaping from the separator has a lower methane content than expected implies that the water expelled by the separator contains more methane than was foreseen. The loss of water in the discharged water (from the separator and from the washing column) becomes the main problem to deal with in order to optimise the design of the equipment. This fact argues in favour of positioning the separator at a shallow depth. A depth of 30 m seems too much, given the loss of methane produced; the optimal depth foreseeable is thus 25 m, maybe even 20 m.