Tar Sands: Not Just Carbon Dioxide | nd-aktuell.de

Since the beginning of the millennium, the growing hunger for energy raw materials has led to the search for ever more complex ways of exploiting deposits. Production is usually energy-intensive and risky for the environment, as was shown, among other things, by the explosion of the BP “Deepwater Horizon” drilling platform in 2010. This pumped oil from waters 1,500 meters deep in the Gulf of Mexico.

Another example of destructive oil extraction is the mining of so-called tar sands in the north of the Canadian province of Alberta. Primeval forests and various rivers have now been literally dug up in an area larger than England. Tar sands are a mixture of sand and bitumen. The latter is purified using a lot of energy and synthesized into heavy oil, which can then be processed in refineries, essentially like crude oil. In addition to the destruction of the landscape caused by open-cast mining – further in the south of the province, the bitumen is also pumped to the surface from deeper layers using steam and chemicals – large basins with the residues represent a significant environmental problem. Their contents are so toxic that wild animals are kept away from them “National Geographic” magazine writes. Miscarriages and deformities in children are also attributed to the industry.

Burden on ecosystems

In addition to the toxic discharge into the rivers, which then ends up in the human stomach via the fish, acid rain falling in neighboring regions and the outgassing of organic carbon compounds also pose a significant burden on ecosystems and people. Gaseous emissions are apparently considerably larger than previously thought , as a team of Canadian, US, Chinese and Swiss scientists have now discovered. Their measurements and calculations were published in the journal at the end of January »Science« published.

For the study, measurement aircraft flew over various opencast mines and production pumps at different altitudes from April to July 2018. With a CO₂gas analyzer was, on the one hand, CO₂-Content of the air examined and, on the other hand, the volatile carbon compounds contained in it are recorded. The latter were converted into CO using a catalyst₂ disassembled and measured separately. Since we were not interested in the different compounds, but only in the total amount, a total carbon content could be calculated. Methane, which is also emitted to a significant extent through mining and is a very effective greenhouse gas, was excluded from consideration. Finally, the prevailing wind directions were taken into account and the nitrogen oxide concentration was determined in order to have a measure of combustion processes on the ground. These also release volatile organic carbon compounds. These should be eliminated from the data as the goal was to determine the emissions from the funding.

Higher emissions than expected

On the one hand, the researchers found that there are hardly any differences in the intensity of emissions between opencast mines and extraction from deeper sources. On the other hand, they were able to show that significantly more of the often toxic compounds are released than communicated by the industry. Depending on the type of connection, the total amount of carbon determined was almost 2,000 to 6,000 percent higher than expected. Overall, around one percent of the delivery volume evaporates in the form of various gaseous organic carbon compounds. Emissions from tar sands mining are about the same as those in the rest of Canada. Depending on the system examined, they were between two and 40 tons of carbon per hour.

However, these gases should not be confused with carbon dioxide, which is emitted in much larger quantities – around 550 million tonnes annually across Canada. According to the results of the study presented, around 1.6 million tonnes of carbon – excluding methane – are emitted via the tar sands of Alberta. If the investigated compounds were in CO₂ If broken down, this would amount to around 5.9 million tons.

The immediate importance of organic carbon compounds lies in their harmful effects on health. In addition, their degradation products can attack the ozone layer and also stimulate the formation of aerosols, that is, tiny droplets and solids suspended in the air that harm plants, animals and people.