ZEVAC is part of Atmos Energy’s Comprehensive Environmental Strategy
Atmos Energy is committed to reducing our carbon emissions from pipeline maintenance, including venting and flaring. In fiscal year 2021, we piloted and implemented technologies to capture and reinject natural gas when possible, including this pilot project that began in March 2021.
Haltom City, which is five miles northeast of Fort Worth, is upgrading its water drainage infrastructure, which requires lowering about 1,500 feet of a 16-inch steel high pressure distribution natural gas feeder line that supports Atmos Energy’s system in north Tarrant County. The Atmos Energy pipe could not be moved to another location because of limited right-of-way and existing utilities in the area.
To keep gas flowing to customers, a temporary 8-inch pipe was used to bypass the section of the 16-inch line in conflict. The gas from the isolated 16-inch line was injected into the system via a ZEVAC (Zero Emissions Vacuum and Compressor) machine. This compressor unit reduced gas at 385 pounds of pressure to 3 pounds of pressure from the isolated 16-inch pipe and injected it into the system.
The three-foot by five-foot ZEVAC unit is a pneumatic-powered vacuum on one side that suctions natural gas from pipe that needs to be depressurized. The other side of the ZEVAC unit compresses the gas back up to pipeline operating pressure and reinserts it into nearby transmission or distribution piping. The gas stays in the pipe and out of the atmosphere.
Engineer Ken Washington, who facilitated the project with Field Construction Coordinator Michael Scott, saw first-hand how the ZEVAC worked. Even though the pilot is a short-length piping project, Washington believes ZEVAC could be viable as a continued solution for reducing system emissions.
“As Atmos Energy continues to grow and develop, we are always preparing for the future,” he said. “One avenue we are evaluating is reducing the amount of gas released into the atmosphere. The ZEVAC machine showed us that we can successfully relocate and abandon gas pipelines without venting, which is beneficial for the environment and for Atmos Energy. The ZEVAC machine could be very viable in reducing emissions on future pipe replacement projects.”