Power outages are a significant threat to petrochemical plants and refineries in Texas and have proven vexing for some facilities to reduce. The outages can wreak havoc, posing a health and safety risk to workers and to people who live near the plants.
“The sound of a (petrochemical plant) losing electrical power produces a sinking feeling in your stomach. It is a loss of resonance and vibration that is odd and unmistakable,” wrote Donald Schneider, a chemical engineer in League City, Texas.
In 1998, Schneider, a consultant, published a case study of an unnamed petrochemical plant. Despite having a backup power generating facility, the plant suffered a total power failure.
Schneider documented the ensuing cascade of calamities that included explosive hydrocarbons spewing in a “10 foot high spray of vapor and liquid” from manhole covers. Benzene fumes got into the plant’s control room, forcing the operators to put on respirators as they fought to get the plant back up and running. It took four days to return the plant to normal operation.
‘Smoking the whole day’
Then there’s what happened last week on Houston’s east side.
“I couldn’t believe how much smoke was coming. It just kept smoking the whole day,” said Josue Castillo. He lives less than a half mile from the Texas Petrochemicals Corporation (TPC) plant.
On September 23, the entire plant lost power. That forced it to start sending tens of thousands of pounds of butadiene, butane, and other hydrocarbons up a stack to the plant’s emergency flare. The flare burned all day and night and into the next day. That’s what was causing the thick, black smoke Josue Castillo saw wafting across the sky above the subdivision of tidy ranch homes that border the TPC facility.
“We had our neighbors come out and take pictures and people just stop and look at the smoke,” Castillo said. He said this time, the smoke was worse than usual.
“Usually, it just a big ol’ flame.”
Castillo is likely remembering all the other times the plant has lost power. In a check of reports TPC files with the Texas Commission on Environmental Quality(TCEQ), StateImpact found the Houston plant has suffered outages eight times since 2009 (six listed as power outages, two as “plant outage”. TPC did not provide anyone for StateImpact to interview for this story).
A Record of Losing Power
TPC listed causes that included thunderstorms, lightning, faulty wiring, and failed electrical breakers.
The TCEQ said its investigators are reviewing the plant’s record of losing power.
“We definitely need to look at the frequency of the events they’ve had. But until we know what caused this (most recent) outage, I can’t really say there’s a pattern,” said Laura Burnett, the TCEQ’s Air Program Coordinator in Houston.
The TCEQ said the TPC plant had taken actions in the past to prevent plant outages including upgrading the computer controls of its on-site electric generators and making changes to improve the reliability of “critical instrument controls”.
Preventing Explosions But Causing Pollution
“The emergency flare systems are very important to prevent a major explosion in the plants because of all the dangerous materials they’ve got,” says Neil Carman, the Clean Air Director with the Lone Star Chapter of the Sierra Club.
Carman points out that the 2005 catastrophic explosion at BP’s Texas City refinery was the result, in part, of explosive liquids that had nowhere else to go but out into a parking lot next to an overflowing unit. The unit had no emergency flare. A government investigation said a back-firing pickup truck probably ignited the liquids, killing 15 workers.
But Carman is quick to add that while using flares may prevent an explosion, they can still be a threat to the health of nearby residents, especially if the flares burn “dirty”.
“If the flare is smoking, it’s not getting a clean burn,” which Carman told StateImpact becomes even more troubling considering what was released in the TPC event.
“Butadiene is a known, human cancer-causing agent. So it’s a major public health concern.”
The TPC plant had entered into an agreement with the City of Houston in 2005 to spend millions of dollars to lower the release of butadiene. The company said the measures worked and that by 2010, butadiene emissions from flaring were reduced 98%.
Past critiques of the Texas petrochemical industry have cited power outages as major causes of emissions from so-called “upset” events that resulted from sudden malfunctions.
When Squirrels Attack
Plants are supposed to take measures to minimize outages. They have a financial incentive to do so — downtime and the loss of chemicals up a flare stack can cost millions.
The TCEQ’s Laura Burnett said odd as it may sound, it doesn’t take much to knock the power out.
“A snake or a squirrel can cause a plant to go down,” says Burnett. The rodents crawl or gnaw into electrical connections, causing short-circuits. Burnett says plants are expected to take measures to prevent rodent-induced damaged and to install equipment to guard against outages caused by lightning strikes.