Basalt fibre - the future of oil-spill recovery?
Basalt fibre technology originally developed for use in the Soviet space programme is now being touted as an ecologically friendly method of cleaning up oil spills.
At 9:45pm on 20 April 2010, an explosion tore through the Deepwater Horizon drilling rig in the Gulf of Mexico, 52 miles (84km) south-east of Venice, Louisiana. Flames raged on the rig for a further 36 hours until it finally gave way under its own weight and sank to the bottom of the ocean 5,000ft below.
The accident claimed the lives of 11 rig workers and left vast quantities of thick, tarry oil gushing from the exposed well directly into the ocean. The oil continued to spill out until 15 July when it was temporarily capped off. However, complications continued for several months and the spill was not declared 'effectively dead' until 19 September. It was the biggest offshore oil spill in US history and has so far cost BP, who own and operate the Macondo field in which the rig was situated, more than $24bn in cleanup costs and compensation to the individuals, businesses and governments affected. Transocean, who owned and operated the rig, have also paid out $1.4bn.
The environmental cost of the spill has also been significant. Large areas of marine habitat were affected leaving thousands of birds and hundreds of turtles covered in toxic oil. The accident has again highlighted the clear need for more efficient methods of clearing up oil spills, a need many researchers are working on meeting. One group taking on this challenge is Israel-based EcoBasalt, a small team of scientists, engineers and investors developing an oil sorbent made from super-thin basalt fibres.
The fibres are around one micron in diameter and are extruded from the molten volcanic rock to form an extremely light carbon fibre-like material weighing around 20kg per cubic metre. This is hydrophobic and oelophilic, which means that when it comes into contact with oil floating on the <'surface of water, such as in an oil spill, it will soak up any oil without becoming saturated with water and sinking.
The company showcased the nascent technology during the CleanEquity conference held in Monaco earlier this year. The team claimed the material can absorb as much as 75 times its own weight in oil in as little as 30 minutes. It also has some fairly impressive eco credentials. It is safe for humans and any plant and animal life and almost 95 per cent of the oil absorbed can be recovered and reused. The basalt itself can also be recycled and mixed with asphalt for use in road construction.
"Two and a half years ago we discovered the idea and thought here is a very interesting story," says Vadim Manov, VP of marketing. "My background is in marketing and the other members have backgrounds in finance and engineering, so we formed a team. We started to study the field and the market and to investigate how we could take it forward and what the challenges were."
Out of this world technology
While the team members all come from disparate backgrounds, the technology has a backstory that could have been lifted from the pages of a Cold War spy thriller. It was originally developed by Professor Yuli Gor, an aeronautics specialist who spent many years working on the Soviet Soyuz space programme. The technology used in the production of the fibres was part of a programme to develop highly efficient insulation for spacecraft. Prof Gor later immigrated to Israel taking the knowledge of basalt fibre production that he had developed on the Soyuz program with him.
"While Prof Gor was working for the soviet space programme he was researching methods of providing better insulation for equipment that was to be sent into space," Manov explains. "One of the most important issues in space flight is how you insulate your devices because the conditions are, of course, totally different. There are different forces and temperatures to deal with and if you are talking about putting human beings in space then the tools around them have to be very well insulated for obvious reasons.
"By insulation I mean not only thermal, insulation against the cold, but also insulation against the electromagnetic radiation in space that can destroy the guidance systems of the rockets and also insulation against gamma radiation."
Manov continues: "Basalt fibre has some specific properties of insulation that function better than lead. Of course the difference in weight between lead and basalt fibre is enormous, so it can be a very useful material for insulation of all kinds."
So how did a material originally designed for use in the insulation of spacecraft end up being touted as the new wonder material for cleaning up oil spills?
"I think essentially it came almost as a coincidence through various experiments," EcoBasalt CEO Robert Barzelay explains. "It's like Archimedes jumping out of the bath. Suddenly this property of oil absorption was discovered. It's interesting because basalt is very inert, there are not many things you can do with it. Traditionally it's a solid building block. It goes back at least as far as the ancient Egyptians who used it to build roads and pyramids."
Basalt is a commonly occurring volcanic rock that is formed by the rapid cooling of molten lava near to the Earth's surface. It has a fine grained structure as a direct result of the fast cooling and is composed of the minerals plagioclase, pyroxene and olivine.
Thanks to its inert nature, basalt is hardwearing and resistant to all manner of potentially corrosive materials such as salts, acids and alkali, as well as fungi, algae and other microorganisms. It can also operate under a wide range of temperatures (from -196'C to 700'C), making it suitable for use in the colder areas of the world's oceans.
While the story surrounding the product's development is intriguing, Manov says the team's journey so far has been far from easy.
"Up until now we have been entirely self-funded," he says. "I think this is because our case is totally out of the box, especially considering the fact that the technology is coming from the former USSR. The West is only now coming up to speed with basalt fibre technology."
Regardless of these setbacks, the team has been pushing forward with developing the material. They say they are ready to build the production lines to produce the material and that process can be scaled up easily and rapidly if and when demand increases. Their aim is to get the product to market within a year, though there is still one significant challenge to overcome.
"It has been tested in the US, Russia and Israel in large bowls. The absorbent material is finished," says Barzelay. "The only thing we have to do now'is to make sure it stays on the water. The'next step in the development of our product is to package it in a way that it will stay on the top of the sea without getting washed away.
"It cannot sink as it is lighter than water, as is oil, and it doesn't absorb one drop of water," adds Barzelay. "But if you simply throw it on the water it will first go into the air. It will not stay on the water by itself. We are developing this now with experts from Australia who make floating devices for aircrafts after they crash."
According to the team's research there is an average of 500 oil spills across the globe daily, making an annual total of around 200,000. These are, of course, mainly smaller scale requiring much less effort to contain than the headline grabbing disasters such as the Deepwater Horizon or Exxon Valdez.
The basalt fibre sorbent could potentially be used by oil drilling rigs, pipelines, marine salvage companies, and fisheries, for example, to mop up smaller spills. And who knows, should another large scale spill occur perhaps basalt fibre could limit its impact.
Oil spill technology
Of course the team at EcoBasalt aren't the only ones looking for cleaner, more efficient methods of cleaning up oil. Scientists at two US universities are also developing similar oil sorbent technologies.
Daniel Hashim, a researcher based at Rice University, Houston, Texas, and an international team of materials scientists have published a paper in Nature Journals detailing the impressive oil-absorbing properties of carbon nantubes that have been treated with boron. The introduction of boron into the carbon puts kinks into the nanotubes as they grow and also promotes the growth of covalent bonds, which helps give the resulting sponge-like material considerable strength.
The blocks of nanotube sponge are superhydrophobic and oleophilic, meaning they readily absorb any oil they come into contact with, as much as one hundred times their own weight, but also repel water and float. They can be used to absorb oil, which can then be burnt off so the sponge can be used to soak up more oil or to store the oil for later retrieval.
So far, the material has only been tested in the lab on a small scale but Hashim is confident it could be used in much larger quantities.
"These samples can be made pretty large and can be easily scaled up," he says. "They're super-low density, so the available volume is large. That's why the uptake of oil can be so high."
At the other end of the country, Professor Mike Chung, a chemist working at Pennsylvania State University, has also proposed a solution. Named PETROGEL, Chung's material is a foam composition made from a polyolefin, a family of polymers that includes polypropylene.
When it comes into contact with a spill the material rapidly absorbs up to 40 times its own weight in oil and transforms into a soft oil-containing gel. This gel can then be collected and transported, refined into a liquid and then refined as a regular crude oil. The cost of the material is likely to be low too. The university expects it to be around $5 per kilo.
Chung has many years of experience of working in the field and was an employee of Exxon during the Exxon Valdez oil spill in Prince William Sound, Alaska, in 1989.
"Most of the methods used in the recent BP oil spill in the Gulf of Mexico were decades-old, low-tech, manpower-intensive methods, and some of the dispersants had unknown environmental consequences," he says. "The goal is to clean up spills in a more effective manner - while being easier on the environment."
Penn State has trademarked the material and plans to license it in the near future.
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