NASA outreach program reduces risk involved with recycling propane tanks

Titusville, FL— Assistance from the NASA-funded Space Technology Outreach Program (SATOP) has solved a serious safety issue involving discarded propane tanks. SATOP is operated by the Technological Research and Development Authority (TRDA).

When the Environmental Protection Agency (EPA) recently mandated new, safer valves for 50-pound barbecue grill propane tanks, owners could no longer refill older tanks and there was no way to legally dispose of the containers because of the hazardous residue left inside.

So consumers have resorted to leaving them near landfills or hiding them inside discarded refrigerators or other large appliances, according to Sonia Gribble, president of Tri-State Scrap Metal, Inc.

The Asheville, North Carolina based company recycles tin, steel, aluminum, copper, brass and other materials from throughout the Southeastern US. The outfit handles several thousand propane tanks annually, she said, including a recent single batch of 1,000.

“Not long ago, one of my heavy equipment operators accidentally dug a hole about three feet deep into the ground when he was loading other scrap metal because a tank was hidden inside,” Gribble said. “There was a small explosion. That’s very scary.”

And it wasn’t the first time.

“When we travel to county landfills, we’re constantly encountering propane tanks,” she noted. “It’s very dangerous because there are still fumes inside. It’s especially hazardous if anyone’s smoking in the scrap metal piles. The public really needs to be educated about this environmental and safety issue.”

Ultimately, Tri-State Scrap Metal wanted to develop a tool or methodology that would help the company “diffuse” the dangers presented in handling the tanks. Gribble heard about SATOP and decided to ask the program to help. SATOP provides free engineering assistance to small businesses with technical challenges through the expertise of the program’s Alliance Partners, 50 aerospace companies and universities involved in the U.S. Space Program.

Robert Gottlieb, an associate technical fellow at The Boeing Company/Johnson Space Center, a SATOP Alliance Partner, solved the problem in about two hours.

“I wanted to make it a one-stroke operation; something clever but simple,” he said. “I wondered what everyday tool would be lying around a machine shop operation. I figured they’d have to have an air compressor. I gave them a sketch of the idea and they took it from there.”

His design incorporates a brass (which doesn’t create a spark) elbow that’s welded over the top tank opening. A hole is then drilled dead-center through the top and a tube is inserted through the hole toward the tank bottom. An air gun propelling 80-100 psi is then attached to the piping.

“With the push of a button, poof, it blows a blast of air to the bottom of the tank and the propane squirts back through the elbow,” he said. “Since the tubing is centered at the bottom and not along the sides, the air pushes all of the propane above it up and out the hole. And there’s no spark. One second and it’s done.”

Gribble is delighted with the win/win solution. “There are no fumes left and it’s safe to do,” she said. “Now, thanks to SATOP, I have good, clean, recyclable steel and there’s no safety hazard to our workers or the public.”