Newhouse moves into the shadow of a cracking tower to consider this. After 26 years at Exxon, he really likes working for Valero. He’s proud of their clean record, especially compared to the BP plant across the road, which the EPA in 2006 named the nation’s worst polluter. The thought of all this incredible infrastructure out of control, torching itself, makes him wince.
“Okay. Everything would burn until all the hydrocarbon in the system was gone. But,” he insists, “it’s very unlikely that fire would spread beyond the property. The pipes that connect the Texas City refineries all have check valves to isolate one from another. So even when you see plants explode,” he says, gesturing across the road, “adjacent units aren’t damaged. Even if it’s a huge fire, fail-safe systems are in place.”
E.C. isn’t so sure. “Even on a normal operating day,” he says, “a petrochemical plant is a ticking time bomb.” A chemical plant and refinery inspector, he’s seen volatile light petroleum fractions do some interesting things on their way to becoming secondary petrochemicals. When light-end chemicals such as ethylene or acrylonitrile—a highly inflammable precursor of acrylic, hazardous to human nervous systems—are under high pressure, they often slip through ducts and find their way to adjacent units, or even adjacent refineries.
In the event that humans were gone tomorrow, he says, what would happen to petroleum refineries and chemical plants would depend on whether anybody bothered to flip some switches before departing.
“Supposing there’s time for a normal shutdown. High pressures would be brought down to low pressure. Boilers would be shut down, so temperature isn’t a problem. In the towers, the heavy bottoms would cake up into solid goop. They would be encased in vessels with steel inner layers, surrounded by Styrofoam or glass-fiber insulation, with an outer skin of sheet metal. Between those layers there’s often steel or copper tubing filled with water to control temperatures. So whatever is in them would be stable— until corrosion set in from the soft water.”
He rummages in a desk drawer, then closes it. “Absent any fire or explosion, light-end gases will dissipate into the air. Any sulfur by-product lying around will eventually dissolve and create acid rain. Ever see a Mexican refinery? There’re mountains of sulfur. Americans ship it off. Anyhow, refineries also have big tanks of hydrogen. Very volatile, but if they leaked, the hydrogen would float away. Unless lightning blew it up first.”
He laces his fingers behind his curly, graying brown hair and tilts back in his office chair. “Now that would get rid of lot of cement infrastructure right there.”
And if there were no time to shut down a plant, if humans were raptured off to heaven or another galaxy and left everything running?
He rocks forward. “At first, emergency power plants would kick in. They’re usually diesel. They would probably maintain stability until they depleted their fuel. Then you’d have high pressures and high temperatures. With no one to monitor controls or the computers, some reactions would run away and go boom. You would get a fire, and then a domino effect, since there’d be nothing to stop it. Even with emergency motors, water sprayers wouldn’t work, because there’d be no one to turn them on. Some relief valves would vent, but in a fire, a relief valve would just feed the flames.”
E.C. swivels completely in his chair. A marathoner, he wears jogging shorts and a sleeveless T-shirt. “All the pipes would be conduits for fires. You’d have gas going from one area to another. Normally, in emergencies you shut down the connections, but none of that would happen. Things would just spread from one facility to the next. That blaze could possibly go for weeks, ejecting stuff into the atmosphere.”
Another swivel, this time counterclockwise. “If this happened to every plant in world, imagine the amount of pollutants. Think of the Iraqi fires. Then multiply that, everywhere.”
In those Iraqi fires, Saddam Hussein blew up hundreds of wellheads, but sabotage isn’t always needed. Mere static electricity from fluids moving through pipes can spark ignition in natural-gas wells, or in oil wells pressurized with nitrogen to bubble up more petroleum. On the big flat screen in front of E.C, a blinking item on a list says that a Chocolate Bayou, Texas, plant that makes acrylonitrile was 2002’s biggest releaser of carcinogens in the United States.
“Look: If all the people left, a fire in a gas well would go until the gas pocket depleted. Usually, the ignition sources are wiring, or a pump. They’d be dead, but you’d still have static electricity or lightning. A well fire burns on the surface, since it needs air, but there would be no one to push it back and cap the wellhead. Huge pockets of gas in the Gulf of Mexico or Kuwait would maybe burn forever. A petrochemical plant wouldn’t go that long, because there’s not as much to burn. But imagine a runaway reaction with burning plants throwing up clouds of stuff like hydrogen cyanide. There would be a massive poisoning of the air in the Texas-Louisiana chemical alley. Follow the trade winds and see what happens.”
All those particulates in the atmosphere, he imagines, could create a mini chemical nuclear winter. “They would also release chlorinated compounds like dioxins and furans from burning plastics. And you’d get lead, chromium, and mercury attached to the soot. Europe and North America, with the biggest concentrations of refineries and chemical plants, would be the most contaminated. But the clouds would disperse through the world. The next generation of plants and animals, the ones that didn’t die, might need to mutate in ways that could impact evolution.”
ON THE NORTHERN edge of Texas City, in the long afternoon shadow of an ISP chemical plant, is a 2,000- acre wedge of original tall grass donated by Exxon-Mobil and now managed by The Nature Conservancy. It is the last remnant of what were 6 million acres of coastal prairie before petroleum arrived. Today, the Texas City Prairie Preserve is home to half of the 40 known remaining Attwater’s prairie chickens—considered the most endangered bird in North America until the controversial 2005 spotting in Arkansas of a lone ivory-billed woodpecker, a species hitherto believed extinct.
During courtship, male Attwater’s prairie chickens inflate vivid, balloon-like golden sacs on either side of their necks. The impressed females respond by laying a lot of eggs. In a world without humans, however, it’s questionable whether the breed will be able to survive. Oil industry apparatus isn’t all that has spread across their habitat. The grassland here once ran clear to Louisiana with hardly a tree, the tallest thing on the horizon being an occasional grazing buffalo. That changed around 1900 with the coincidental arrival of both petroleum and the Chinese tallow tree.
Back in China, this formerly cold-weather species coated its seeds with harvestable quantities of wax to guard against winter. Once it was brought to the balmy American South as an agricultural crop, it noticed there was no need to do that. In a textbook display of sudden evolutionary adaptation, it stopped making weatherproof wax and put its energy into producing more seeds.
Today, wherever there isn’t a petrochemical stack along the Ship Channel, there’s a Chinese tallow tree. Houston’s longleaf pines are long gone, overwhelmed by the Chinese interloper, its rhomboid leaves turning ruby red each fall in atavistic memory of chilly Canton. The only way The Nature Conservancy keeps them from shading out and shoving aside the bluestem and sunflowers of its prairie is with careful annual burning to keep the prairie chicken mating fields intact. Without people to maintain that artificial wilderness, only an occasional exploding old petroleum tank might beat back the botanical Asian invasion.
If, in the immediate aftermath of
Or, if the faith of Valero Energy’s Fred Newhouse in system safeguards proves warranted—or if the departing oilmen’s last loyal act is to depressurize towers and bank the fires—the disappearance of Texas’s world champion petroleum infrastructure will proceed more slowly. During the first few years, the paint that slows corrosion will go. Over the next two decades, all the storage tanks will exceed their life spans. Soil moisture, rain, salt, and Texas wind will loosen their grip until they leak. Any heavy crude will have hardened by then; weather will crack it, and bugs will eventually eat it.
What liquid fuels that haven’t already evaporated will soak into the ground. When they hit the water table, they’ll float on top because oil is lighter than water. Microbes will find them, realize that they were once only plant
