Monday, August 27, 2018 by Frances Bloomfield
The system of separating water and oil is one that can be laborious and expensive. Fortunately, engineering researchers from the University of Texas at Austin have come up with a simpler yet more efficient method of removing oil from water: magnetic nanoparticles.
“It’s a simple idea,” stated Hugh Daigle, a petroleum and geosystems engineering professor. “We are leveraging the magnetic properties of these nanoparticles to get them to stick to the oil droplets and essentially magnetize the oil droplets so they can be pulled out with a magnet.”
According to Science Daily, Daigle and his colleagues were inspired by the versatility of nanoparticles, which are tiny particles that can be coated with different chemicals and utilized in a vast range of areas and industries. Nanoparticles have seen use in the fields of medicine and electronics, and this prompted the team to explore the possible uses of nanoparticles in oil production. (Related: Silver nanoparticle solutions can treat difficult mouth infections.)
For this purpose, the team designed positively-charged surface coatings for magnetic nanoparticles. When exposed to oil, these nanoparticles would latch onto the negatively-charged oil droplets via electrostatic attractive force. In situations where the reverse is in effect, then the magnetic nanoparticles can be coated with negatively-charged surfaces for target substances with positive charges. The entire process has been documented and described in a study published in the Journal of Nanoparticle Research.
“This new technique is really aimed at removing that little bit of oil in that water that needs to be removed before you can consider it treated,” explained Saebom Ko, a research associate in the Department of Petroleum and Geosystems Engineering. “The advantage of employing magnetic nanoparticles is that the small oil droplets that attach to the nanoparticles are much more quickly separated from water than traditional physical separation processes because magnetic force can be orders of magnitude larger than gravitation.”
On the use of their nanoparticles in oil and gas production, Ko had this to say: “We are currently developing a chemical-free regeneration process to reuse nanoparticles. Other regeneration methods use chemicals to extract the oil, resulting in production of other hazardous waste. We believe that by recycling and reusing nanoparticles, it could not only reduce operational costs, but it could be an environmentally friendly process that reduces hazardous waste.”
Since their technique is flexible and easy to execute (taking mere seconds in laboratory tests), Ko, Daigle, and the other members of the team believe that it has applications beyond that in onshore and offshore drilling operations. For one, they’ve considered utilizing the nanoparticles to develop a more efficient method of cleaning up oil spills in the ocean. Another possibility is using the nanoparticles to remove contaminants, like lead and mercury, from drinking water.