Natural Gas Explosion Kills 5 at CT Power Plant
Aerial view of the Kleen Energy Systems LLC power plant following the blast. (image: Bettina Hansen via Hartford Courant.com)
As reported by Reuters, a natural gas powered-electrical plant near Middletown, CT exploded yesterday, killing five people and injuring a dozen others. It was initially believed that some 50 construction workers were trapped in the building’s rubble, but those reports appear to be inaccurate, as the Hartford Courant has reported that all of them are now accounted for.
In early reports, officials suspected that a gas leak originating from pipes going in to the building was the cause of the combustion, because workers were purging these lines of air as the explosion occurred just before 11:30 in the morning.
The blast was so powerful that it blew out windows from neighboring houses and rocked the ground beneath cars and houses 20 miles away. An investigation is currently underway.
The 620-megawatt plant called Kleen Energy Systems LLC was expected to start operations this summer.
Purging is a standard procedure used to prepare pipes and tanks for the storage and distribution of combustible gases.
Natural gas (mostly methane) is highly combustible for the same reason that it is an excellent fuel: its chemical bonds contain a great deal of energy but are also easily broken apart in the presence of oxygen. When used as fuel, this combustion reaction is sustained in the form of burning which releases energy over time. In an explosion, the gas’ exposure to oxygen is not controlled and its energy is released all at once. When air gets in a gas line, it provides the oxygen necessary for a combustion reaction to take place. The high pressure makes it possible, for the smallest spark—from a malfunctioning piece of equipment, from heat—to produce an explosion.
That’s why it’s so important for pipeline installers to remove all the air from a pipe before filling it with gas. This is done by displacing the air with another, non-combustible gas such as nitrogen. Only when all of the air has bled out is the pipe completely safe for methane.
The Wall Street Journal reported that an official said a propane heater, identified as a “small flame device” by a victim’s son, was the source of the spark behind the plant’s explosion.
Last spring, an explosion at a Slim Jim factory in North Carolina that killed three was also attributed to a natural gas line purging accident. The incident prompted officials to urge the U.S. Chemical Safety Board to adopt emergency changes to the federal safety guidelines for fuel gas purging. As the AP reported in September, the Board’s upper management denied the request, citing jurisdiction issues with the way the change would be applied. Although details behind the Kleen Energy plant explosion are still unknown, it is tragic that only four days ago, the Board voted to approve those recommendations.
