It has the air of nothing, but there is a deposit of natural gas which does not reject carbon dioxide, or almost. The systems of illegal securement of the methane of In Salah (Algeria) separate gases and re-inject CO2 in basement. Every year, these would be not less than eight hundred thousand tons of this gas with greenhouse effect who would be sequestrated, with an as a result reasonable cost: 14 dollars the ton. A plan drives by the Algerian national society, Sonatrach, the oil tanker PO BOX, and the Norwegian Statoil business company.

In exit of well, the gas of In Salah contains in principle 7 % of carbon dioxide. A content which it is necessary to bring down in 0,3 % before being able to export the methane towards Europe. As all wells of gas, boring of In Salah are therefore equipped with devices of separation of gases. But contrary to most farms, the carbon dioxide is not rejected in the atmosphere. It is compressed and injected into a pocket of water located under the deposit of gas. The whole for a hundred million dollar investment, is only 2,5 % sums invested in In Salah for gas working. (2)

Naturally, this sequestration is not without risk, and the geologists drive a surveillance non-stop. Because the carbon dioxide could, for example, earn water-bearing one neighbouring, and acidify the water so as to make it unusable for agriculture. In principle, he is blocked for centuries under a layer of loam, but nobody is sheltered by a bad surprise.

While the hunt for the Algerian gas continues, several other plans of working as for Total, Gas of France and Repsol could be equipped with a system of sequestration of the carbon dioxide. And the European Union, which plans to help a dozen of experiments of capture and stocking of carbon (DIRECT CURRENTS) in the industrial ladder, follows affair closely.

The idea of capturing CO2 taken out from the wells of oil and of gas made the way. In Norway, the farms of Snohvit (gas) and Sleipner (oil) make it every day. But in the case of Sleipner, the re-injected gas also serves for putting boring under pressure to improve the recovery of the oil. Less carbon dioxide, therefore, in the course of extraction, to multiply it at the exit of the chimneys of power stations or of the pots of exhausts not sure which the planet earns it!

It is for this reason that organisations environmentalists see this running of a very bad eye in sequestration. For the moment, in spite of pressures exercised by countries as Norway, Australia and Canada, the negotiators of the United Nations in Poznan (Poland) left the idea of giving licences of programmes to the States which would sequestrate CO2 of their farms of hydrocarbons (1). An idea which risked certainly forcing the development of these techniques, but also postponing the installation of sources of more lasting energies and without carbon. Indeed, alone the cost of sequestration again makes move back the industrialists.

(1) In December was held in Poznan a conference on the climate of the UNO, intended to prepare a future international treaty which would take over the Kyoto protocol.

(2) Read the article of Business Week (in English).

Picture: © Denis Delbecq - on 2008