The ruptured pipeline and the expanding environmental disaster in Mayflower, Arkansas has a back story that began in Athabasca, Alberta. First the local story. To date Exxon has removed about a half a million gallons of a crude oil/water mixture from the area. News photos show that not only has the oil fouled numerous homes in the area but also run into nearby wooded areas and Lake Conway. Several families were evacuated, and clean-up of the affected neighborhood may take months or more.
If that was all to the story it would be bad enough, but the source of the crude oil adds a much larger degree of environmental degradation in Canada and a greater risk of degradation here in the United States. The oil flowing through (or out of) the pipeline in Mayflower began as a tarry substance known as bitumen. The stuff could only be described as a relative of crude oil. It is thick as cold molasses and is commingled with sand in vast beds in Northeastern Alberta, Canada.
Production of crude oil from the sands begins with a huge strip mining operation. The gunk is excavated and then trucked to processing facilities where it is heated with steam to lower the viscosity so it can be separated from the sand and clay. It is still too viscous to send through a pipeline so the bitumen is chemically processed with hydrogen.
The total process from strip mining, steam heating, and hydrogenation requires a large amount of energy and local environmental degradation , making this source of crude oil costly and inefficient. In fact this whole process would be near impossible were it not for a source of natural gas to provide energy for the processing. It makes one wonder why we just don’t buy the natural gas, instead of the oil resulting from the process?
The processed crude oil then makes its way through a network of pipes including the Exxon pipeline in Mayflower, to refineries in the midwest and gulf coast region. A measure of just how inefficient the production and shipment of the oil can be seen in a calculation called the EROEI, or the energy returned on energy invested. The higher the ratio the more efficient the process. For the tar sands the ratio is less than three to one.
The production of fossil fuels as an energy source is absolutely and completely dependent on the energy returned on energy invested (EROEI). If it takes more energy to obtain a fossil fuel than the fossil fuel delivers on use, then it is not an energy source. It is a waste of energy.
Consider the EROEI of some other fuel sources. In the earlier decades of the 20th century, the EROEI for crude oil in the U.S. was close to 100:1, that is to say one barrel of oil invested in exploration/production produced about 100 barrels of oil. Conventional crude oil today has an EROEI of about 20:1. Compare this to the EROEI for tar sands at less than 3:1.
Paraphrasing a late-night infomercial, BUT WAIT, THERE’S MORE. Lower EROEIs mean greater amounts of greenhouse gases emitted for useful energy produced. Fuels such as natural gas have relatively low greenhouse gas emissions compared to conventional crude oil, which has less than coal. The low EROEI means that bitumen processing and use makes it as bad as coal in terms of greenhouse gas emissions.
Additionally, a lot of water is required to process the tar sands. Roughly 5-10 barrels of potable water are converted to oil fouled waste for each barrel of oil produced. Although there are tar sands in Utah and thereabouts, the resource may never be extracted due to the lack of process water.
The tar sands of Alberta is the raison d’etre for the proposed Keystone XL pipeline, which will be ten times the size of the ruptured pipeline in Mayflower. We really don’t need the additional pipeline capacity, it causes environmental degradation where it is extracted, and has the potential for more damage due to spills such as is occurring here, and its use will greatly contribute to global warming.