The coke comes from a refinery alongside the river owned by Marathon Petroleum, which has been there since 1930. But it began refining exports from the Canadian oil sands — and producing the waste that is sold to Koch — only in November. Marathon Petroleum’s plant in Detroit processes 28,000 barrels a day of the oil sands bitumen.
Petroleum coke, a waste byproduct of refining oil sands oil, is piling up along the Detroit River |
Almost 56 percent of Canada’s oil production is from the petroleum-soaked oil sands of northern Alberta, more than 2,000 miles north.
An initial refining process known as coking, which releases the oil from the tarlike bitumen in the oil sands, also leaves the petroleum coke, of which Canada has 79.8 million tons stockpiled. Some is dumped in open-pit oil sands mines and tailing ponds in Alberta. Much is just piled up there.
Coke, which is mainly carbon, is an essential ingredient in steelmaking as well as producing the electrical anodes used to make aluminum. While there is high demand from both those industries, the small grains and high sulfur content of this petroleum coke make it largely unusable for those purposes.
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.
The Environmental Protection Agency will no longer allow any new licenses permitting the burning of petroleum coke in the United States. Overseas companies see it as a cheap alternative to low-grade coal. In China, it is used to generate electricity, adding to that country’s air-quality problems. There is also strong demand from India and Latin America for American petroleum coke, where it mainly fuels cement-making kilns. (NYT, 5/17/2013, Photo: Fabrizio Costantini for The New York Times)
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