LNG demo tries to calm people's fears
By Elise Hamner City Editor
Saturday, December 9, 2006 12:28 AM PST

What's odorless, colorless and looks like boiling water?

Give up?

Liquefied natural gas.

“To date, I haven't been able to light an LNG cloud with a lit cigarette,” he said.

People were chuckling. Later, in his demonstration, he was to back up his claim with proof.

Richardson didn't pull a white frock over his green Dockers and blue dress shirt. Instead, he settled for fold-up plastic glasses and elbow-length ski gloves. He went to work at a table outside.

He lifted a gallon-sized metal thermos and slowly poured LNG into a glass beaker. A cloud of white vapor billowed out the top momentarily, but then wisped away, leaving what looked like a bubbling jar of champagne. (Water may freeze at 32 degrees Fahrenheit, but LNG boils at minus 260 degrees.)

“What cloud comes off a pool of LNG is water condensing out of the atmosphere, because natural gas is clear,” Richardson said.

There was a stem of yellow carnations on the table. Richardson reached for them. Those blooms were doomed.

Parking lot laboratory

“If you stick a finger in and count to five, you're going to freeze some tissue,” he said.

Richardson dipped the flower blooms into the beaker, held them there for a time and pulled them out. When he smacked the frosted flowers on the table, they shattered like glass.

Then came the rubber super balls. He first dropped a tiny hot-pink one in the liquid, then a fist-sized one. The LNG frothed over the beaker rim, with droplets skittering across the table and out across the concrete. No worries.

Richardson soon plucked out the balls with metal tongs and bounced them, one by one, on the ground. They thudded like chunks of plastic. He slammed one with a hammer hoping to break it like a piece of metal frozen by LNG, but no luck. The pink missile rocketed through the crowd to a parking lot.

Leaving his students no time for a mental rest, Richardson stepped away from the table and poured LNG into two pans. One aluminum pan had been empty, the other half-full of water, and from that pan, the vapor swirled into a huge cloud, blowing across the ground.

The crowd stood mesmerized, as people do watching flames, but this smoke was icy. The LNG floating atop the water quickly evaporated, leaving a water pool with chunks of ice.

But the crowd wanted flames.

Richardson and a helper pulled out a cigarette and lit it. Magician-quick, the showman whipped the cigarette back and forth through the LNG vapors. There was no ignition.

Ultimately, he had to thrust a household flame igniter into the air just above the diesel and LNG pans. With some patience, the vapors caught fire. The diesel, which needed paper to fuel the fire, sent thick, black smoke into the air, while the natural gas burned clean.

“The key is the ignition rate,” Richardson said.

Science 101

“I actually understood this and it's physics,” one woman told a coworker part way through Richardson's presentation.

Natural gas ignites at 999 degrees. Gasoline autoignites at 899 degrees, he said.

LNG doesn't leave behind toxins from a spill, according to industry publications. But, it can kill a person through asphyxiation by concentrated odorless fumes or by freezing (cryogenically) someone who falls in a pool of it.

“There's going to be no ring in the bathtub and no toxicity in the water. ... If a duck swims into it, it's going to freeze,” Richardson said.

And when there's a spill, it's best to corral the LNG. That's where Richardson shares his expertise in training emergency responders.

Controlling a spill

“If I'm a first responder and I can contain a spill, I'm halfway home,” he said.

Halfway.

When there's a spill, LNG flows along the ground slowly absorbing all of its warmth. As it warms, vapors go vertical. On water, LNG spreads and evaporates more quickly across the surface with vapor billowing skyward.

For firefighters or first responders, the danger area is around the edges of the cloud. That's where oxygen and methane mix and with just the right portions - and a source for ignition - the gas will ignite (see sidebar).

Richardson was adamant, however, that in an open area, a spill won't cause an explosion. There isn't percussion, he said, or a blast.

“I have never felt a pressure wave from LNG,” he said.

Rather, flames will burn above the pooled LNG.

Dry chemical puts out the fires.

“That's going to be the weapon of choice,” he explained.

First responders also can use heavy foam to knock down a larger fire. That's the stuff firefighters learn at Richardson's training school in College Station, Texas. For his training and demonstrations, Richardson is apt to dump 2,000 to 3,000 gallons into concrete areas. For those classes, one of his cohorts, laughingly referred to as Bad Bob, dons a fire suit and carries a fiery pole, tapping the edges of the vapor cloud to set the blaze.

If the LNG is on the ground, Richardson said, it moves slowly.

“I tell firefighters the flame spread is so slow you could almost outrun it,” he said. “In fact, I've seen guys outrun it. They were highly motivated.”

Joking aside, Richardson did talk about injuries. For first responders and others around a spill, there's the possibility of frostbite. Fire suits and gear won't save them if they fall into a pool of it. If they grab LNG-frosted equipment with bare hands, they'll stick to it.

But as to effects or potential damage from a large-scale spill - hundreds of thousands or millions of gallons - Richardson wouldn't speculate.

Sure, there are studies out there, Richardson said. But those are computer modeling guesses, not proved practical experience.

Someone has floated an industry proposal to do a large-scale LNG discharge onto water, Richardson said. But it's merely talk right now. Before any such experimenting, the idea would have to be debated and approved by federal permitting agencies.

Answers to liquefied natural gas questions

Saturday, December 9, 2006 12:28 AM PST

The following are some questions and answers from a presentation on the science behind liquefied natural gas. It was sponsored by the Oregon International Port of Coos Bay and Jordan Cove Energy Project. The presenter and answer guy was Kirk Richardson, program supervisor of LNG/marine firefighting at the Emergency Services Training Institute, at Texas A&M University.

Question: People have said an LNG spill or accident can cause damage from within 1 to 7 miles. North Bend City Councilor Janet Rubin asked if Richardson thought, if there were a spill and fire at an LNG terminal on the North Spit, would it wipe out the North Bend airport.

Answer: Richardson said, for example, if an LNG tanker was offloading at a terminal and for some reason the ship pulled away from the dock, offloading arms have quick-close valves designed to automatically close off piping. Such an occurrence might amount to a 15-gallon spill.

A: No.

Q: Can lower quality LNG, that which has higher concentrations of butane or ethane, cause an explosion?

A: There could be a flameless explosion, a vaporization bang or localized pressure wave, Richardson said.

Q: In a worst-case scenario such as a great earthquake breaking open LNG storage tanks, what if the wind blew a vapor cloud from the North Spit into town?

A: With a higher wind speed, there would be less cloud and more mixing of the vapors into the air. Computer models have tried to predict outcomes from such large spills, Richardson said. But, he added, those studies not real-case scenarios.