LANCELOT (Lake Nyos carbon emission lowering by olivine treatment)

Abstract

A catastrophe hit Lake Nyos in Cameroon in August 1986, when a dense cloud of CO2 erupted from the lake and rolled down the slope of the volcano, killing more than 1,700 people. To prevent a repetition, a geyser-like system has been installed, which lifts the bottom waters. When the pressure diminishes, bubbles of CO2 nucleate and bubble upward, thus preventing the accumulation of this greenhouse gas in the bottom waters. In this note, another way of tackling the problem is proposed, by which the CO2 is transformed into bicarbonate in a layer of olivine spread over the lake bottom. Although the volume of the gas is modest at Nyos, the approach can function as a model for other and more voluminous CO2 emissions in the world, to prevent their escape into the atmosphere.