Petroleum coke is a byproduct of the refinery process of the tar sands oil, which leaves refineries with a huge amount of the coke after it sends the oil onward. The coke usually just piles up (Canada has 79.8 million tons stockpiled), because it's a dirty, and mostly inefficient energy source. But the industrialist/harbingers of the apocalypse Koch Brothers had a better idea: why not sell this high-sulfur, high-carbon waste to countries that don't care about the environment?
And that's exactly what they did. “It comes down to emission controls,” D. Mark Routt, an energy consultant, told the Times. “Other people don’t seem to have a problem, which is why it is going to Mexico, which is why it is going to China.”
But first it's precariously piling up in Detroit. “What is really, really disturbing to me is how some companies treat the city of Detroit as a dumping ground,” said Rashida Tlaib, a Michigan state representative. “Nobody knew this was going to happen.”
Michigan has already asked the Koch corporation to change how it is storing the petroleum coke, but the company has yet to act. And with the increasingly imminent construction of the Keystone XL pipeline, these massive toxic pile-ups will only become more popular inside the United States:
The Keystone XL pipeline will provide Gulf Coast refineries with a steady supply of diluted bitumen from the oil sands. The plants on the coast, like the coking refineries concentrated in California to deal with that state’s heavy crude oil, are positioned to ship the waste to China or Mexico, where it is burned as a fuel. California exports about 128,000 barrels of petroleum coke a day, mainly to China.