Scientists have developed a way to isolate emulsion-causing petroleum compounds. The technique may help lower energy costs for both oil companies and consumers.
Silica, the white powder found packaged with many products as a moisture control agent, can be selectively hydrated, meaning the number of water molecules on the sand’s surface can be controlled.
Scientists selectively hydrated silica so that the surface water layer grew thicker and thicker. When these hydrated silicas were mixed in a glass tube with crude oil, the compounds in the oil that “love” water (hydrophilic) stuck to the water (which was already stuck to the silica). They remained in the tube, stuck to the silica, even after the tube was washed (removing all the petroleum species that didn’t stick to the water and silica).
Next, methanol (an alcohol) was added to “peel” the water off the sand surface, which removed the “water-loving” petroleum species along with it.
In this process, petroleum compounds that love water were separated from those that do not.
Scientists tested a range of water thicknesses and identified the best one to capture this “water-loving” petroleum (see figure). Although this material makes up only 1 percent of the entire petroleum mass, it alone forms an emulsion (vial A in photos). A crude oil that initially forms an emulsion, does not form an emulsion if you remove these compounds.
In short, the scientists isolated from petroleum the compounds that cause emulsions.
Emulsions are an unwanted consequence of the recovery of many crude oils; they may lead to corrosion and equipment failure during refining due to their tendency to carry salt water.
By determining the composition of the compounds present at the oil/water interface, we can help to develop new techniques to effectively break undesirable emulsions and reduce capital costs of extracting oil. In turn, this should reduce consumer costs for petroleum end products like gasoline and diesel fuel.
This research was conducted in the 9.4T FT-ICR Mass Spectrometer at the MagLab's ICR Facility.
Once we isolated the compounds that cause petroleum emulsions, we needed to know what we isolated. Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR MS), a method that is used to weigh molecules (and requires high magnetic fields), is the method of choice for complex mixtures such as crude oil. .
Read the full-length publication, Effect of the Water Content on Silica Gel for the Isolation of Interfacial Material from Athabasca Bitumen, in Energy Fuels.
For more information, contact Chris Hendrickson.