The first permanent degassing column will be
assembled and set up in January 2001 at Nyos. The main part of the funding
comes from the US Office of Foreign Disaster Assistance (OFDA). The
French Embassy in Yaounde and, of course, the Cameroonian Government
also participate in the financial and logistical support.
The OFDA contracted the designing
and assembling of the column, its ancillary instrumentation
and the satellite remote control system to a French Company,
Environnement. The raft
construction was contracted to a Japanese Company, Yoshida
Consulting Engineer Office.
The overall system is rather
similar to the one experimented with at Nyos in 1995.
Special attention has been paid to the instrumentation ( see
below ), both for the purpose of technical surveillance of
the two-phase flow instabilities, and for the collection
some more fundamental parameters .
The polyethylene bars which
constitute the column will be electrically soldered on the
spot. The pipe external and internal diameters are 180 mm
and 145 mm, respectively. The depth of the inlet removal
mouth will be as close as possible to the bottom of the
lake, say, around -205 m.
It is to be noticed that the
dissolved gas concentration considerably increased at 200 m
depth since the last experiment in 1995 ( 9 lgas/lliquid as
compared to 5.5 lgas/lliquid ): the expected self-sustained
fountain will be at a much higher energetic level. The gas
release rate will largely overcome the natural CO2 recharge
(from 2 to 5 Mm3/year).