WASHINGTION – U.S. Naval Research Laboratory (NRL) engineers and the Bureau of Safety and Environmental Enforcement (BSEE) advanced a low-emission burner system’s technological readiness to clean up emulsified crude oil and reduce the Navy’s carbon footprint.
“Our goal at NRL is to transition our combustion knowledge and technology into an effective way to get rid of oil that has been spilled at sea,” said C.J. Pfutzner, NRL mechanical engineer. “The Navy has a real stake in cleaning up oil spills, not only our own, but others around the world.”
The cleanup also includes fuel spills from old ships as far back as World War II that slowly leak, sometimes they are in very remote locations and a small-scale burner such as our own can be a useful means of getting rid of one of those spills, he said.
In response to the needs of the Department of the Interior’s BSEE for a rapid disposal method for emulsified crude oil – the research laboratory developed a crude oil burner and conducted emissions testing of the burner.
“The testing is pretty amazing,” said Steven Tuttle, NRL combustion and reacting transport section head, administer of emissions testing, and burner operator. “We end up shooting flames over 40 feet into the air.”
In collaboration with the U.S. Environmental Protection Agency, NRL researchers collected exhaust measurements of critical species like carbon dioxide, carbon monoxide, soot and other emissions to determine how efficiently the NRL-developed system burns crude oil to compare the emissions with clean air standards, calculate the burn efficiency, and provide metrics of the environmental impact of such a burner.
“This burner will benefit the environment by providing oil spill remediation of emulsified crude oil, which is difficult to dispose of, and oil spills in remote locations, where the carbon footprint of transporting the oil to be re-processed is greater than burning the oil in place,” Tuttle said.
The team took measurements at the NRL Chesapeake Bay Detachment using a 130 feet boom lift fitted with gas and soot instrumentation in December 2019.
“The purpose of this particular emissions testing is to transition the Technology Readiness Level (TRL) of the low-emission, low-pressure atomization and combustor system for emulsified crude oil from TRL 6 to TRL 8 so the system design can be transitioned to a manufacturer,” Tuttle said. “Manufacturers want to make sure that before they transition it to a product, it will be able to meet emissions standards.”
The emissions results revealed that the burner performed comparably well to commercial and industrial burner systems, with a combustion efficiency of 99.9%, carbon monoxide concentrations at almost undetectable levels, and low soot emissions.
“We’re excited about this technology because it’s not only going to get the emulsified crude off of the marine environment, it will help protect our first responders that are out on the water and keep them healthy,” said Karen Stone, BSEE oil spill response engineer and program manager. “We hope this technology can be used closer in-shore; maybe in fast-water environments on rivers and near population centers or in areas that we don’t have a lot of infrastructure, such as off of Alaska.”
Whenever there is an oil spill out on the ocean, there are two possibilities, a surface spill and a sub-surface spill. In both cases, as the oil gets on the surface, wave action and wind starts to actually turn the oil with the ocean water into an emulsion, which is really difficult to ignite or dispose of.
Another challenge is getting there.
“We can’t get to oil spills very quickly - by the time you get the call there is a spill, you get people out to the response area to start collecting the oil, which takes a good 12 to 24 hours to get people on site,” Stone said. “By then, the oil has already emulsified over 33% and cannot be ignited.”
“The NRL-developed emulsified crude oil burner does not exhibit the black plume that is associated with hydrocarbon burns, it’s just a nice clean burn,” Stone added.
The Combustion and Reacting Transport Section at the laboratory addresses the Navy’s basic, applied, and advanced research needs in the areas of combustion, fire science, and a wide range of systems that contain multiple phases, chemical dynamics, and the transport of mass, energy, chemical species, and momentum.