The Colonial Pipeline through which fuel flows from Texas to New York got ruptured last fall, causing a quarter-million gallons of gas to spill in rural Alabama. By the time the leakage was detected during standard inspection, vapors from discharged gasoline were so strong they hindered pipeline repair for days.
Currently, researchers are designing technology that would immediately alert pipeline managers about leaks as the failure occurs, avoiding the environmental disasters and fuel distribution disruptions caused by pipeline leaks.
The researchers have presented their work at the 255th National Meeting & Exposition of the American Chemical Society (ACS). ACS, the world's largest scientific society, is organizing the meeting from March 19th to 22nd. It features over 13,000 presentations on numerous science topics.
The advantage with our sensor is that it can detect very small leaks, and operators can take quick action to repair them. We no longer have to wait until the leak is out of hand. Plus if we are able to develop this system on a larger scale, the same unit would be able to treat the waste and to remediate the soil and water that has been contaminated.
Veera Gnaneswar Gude, Ph.D., Project Leader
Pipelines are presently checked using a device called a smart pig, an electronic sensor that moves through the pipe detecting welding defects or cracks. In spite of systematic inspection, leaks still happen. Gude, who is at Mississippi State University, is building a sensor that would complement this process by providing extra information about the reliability of the pipes. This sensor adheres to the outer side of the pipe and makes the most of the metabolic process of bacteria to detect gas leaks in real time.
In an earlier research, Gude analyzed the use of microorganisms in wastewater treatment, and he has lately turned his focus to designing biosensors from similar species. In the latest study, he is testing bacteria that will elicit a sufficiently measurable cathode voltage while also being able to endure in a marine environment for the application of offshore oil spill detection. For this to be successful, the bacteria have to stay robust through a variety of pressure, alkalinity, and pH conditions.
One type of bacteria he is testing is termed as "electrogenic," which means that it emits electrons to its environment through metabolic processes. Gude built an organic sensor made up of an electrogenic anode composed of bacteria that consume carbon-based material (oil or gas) and expel electrons. The electrons then move across a resistor to a cathode. A diverse set of bacteria, hungry for electrons, are located in the cathode encouraging electron flow. An increase in the metabolic processes of the anode bacteria will match a voltage increase in the sensor, which could alert a technician to a possible leak.
"The sensor is not difficult to implement," says Gude. "Placing the sensor onto a pipe is not a big challenge. It is a very versatile technique."
Presently, Gude is hunting for a medium in which to he can immobilize the bacteria. He is examining high-porosity plastics and bio-based films that improve the surface area that the electrogenic bacteria can cover.
Once sturdy bacteria are identified and immobilized, they can be employed as leak detectors in a variety of oil transport and drilling applications, including fracking. In the future, it may even be possible for the sensor to be sprayed as a coating on the exterior of pipes ensuring that the total length is constantly monitored.
The researcher received financial aid from the National Science Foundation for his study.