Despite the ongoing green “revolution”, around half of Europe’s electricity is still produced from fossil fuels. That’s not likely to change soon. There is hundreds of years-worth of coal, gas and oil still in the ground. Furthermore governments and energy companies around the world aren’t backwards about going downward.
The focus recently has been the Arctic, where several different companies, including Shell, BP and Gazprom, are racing to develop the most lucrative oil and gas fields remaining in the world. The U.S. Geological Survey says the Arctic is the “largest unexplored prospective area for petroleum remaining on Earth” and estimates the region contains about 13% of the world’s total undiscovered oil and 30% of its undiscovered natural gas.
This week Shell was granted permission to start exploratory drilling in the Arctic at Alaska’s Chukchi Sea. Earlier the same week new satellite data from the U.S. National Snow and Ice Data Center revealed that the amount of Arctic sea ice has reached a record low. A neat juxtaposition, further emphasised by the fact that less sea ice will probably make the Arctic more accessible for oil and gas exploration.
Arctic oil and gas exploration is the best example of the extremes engineers will go to in order to secure energy supplies for our consumption, now that all the easy to exploit resources have been or are being used. The environmental and engineering challenges involved in exploiting Arctic oil and gas are massive. From drilling through the ice to transporting the fuels back to where it is used, it’s a daunting task.
Meanwhile on land, the technical solutions required to exploit remaining fossil fuel resources are growing in complexity. Fracking, where high pressure liquids are pumped underground to crack rock strata and flush out the hydrocarbons they contain, is increasingly being used throughout the world to flush out otherwise uneconomical oil and gas reserves. The technique isn’t attracting many fans, unsurprising when it minor earthquakes are detected close to drilling sites.
But there are even more complex techniques in development. Underground Coal Gasification (UGC) basically involves setting fire to coal seams up to half a kilometre underground and collecting the resultant gases. This enables the exploitation of coal that would otherwise be uneconomical to mine. The process requires oxygen and steam to be pumped down a shaft to the seam, where it reacts with the coal to form carbon dioxide, carbon monoxide, methane and hydrogen, a syngas. The syngas is then brought to the surface to be burned to produce electricity, or it can be liquefied into fuels such as diesel.
Coal gasification is not a new technology, but if the thought of starting large fires deep underground in rock strata millennia old doesn’t appeal, a €3 million EU research project called HUGE (Hydrogen Oriented Underground Coal Gasification for Europe) is looking at ways to make sure the process is as safe as possible. Due to finish June 2016, the project is also looking at ways to ensure all the unwanted by-products, such as CO2, are collected and stored and at ways to best utilise the hydrogen also produced.
Researchers in Liège, Belgium have simulated the interior of a coal mine, and tested how pressure and heat changes affected the outcome of coal gasification. At the Barbara mining site near Mikolów in Poland, around 22 tonnes of coal was gasified during an experiment at a rate of 50kg per hour. Some 269 gigajoules were generated by burning the syngas collected on the surface.
HUGE project coordinator Krzysztof Stanczyk, who works in the Polish Central Mining Institute, says: “The idea seems simple but there are many challenges. Underground gasification cannot be controlled to the same extent as a surface process.
“The trials helped us learn how to control the process safely and how to influence the quality of the gas.
The technologies and engineering involved in techniques like fracking, UGC, and in drilling in places like the Arctic, are fascinating, although they don’t get the same level of publicity as renewable sources of energy. The driver behind such challenging exploration and production is ultimately our insatiable appetite for energy. Which is why energy efficiency and sustainability is as important as developing more carbon-free sources of energy. At least it is until someone perfects industrial scale nuclear fusion, or makes solar PV really really efficient….or invents / discovers some other super abundant clean source of energy.