Glen Reynolds brings us this:
A provision in the US Carbon Neutral Government Act incorporated
into the Energy Independence and Security Act of 2007 act effectively
bars the US government from buying fuels that have greater life-cycle
emissions than fuels produced from conventional petroleum sources.
The United States has defined Alberta oilsands as unconventional
because the bitumen mined from the ground requires upgrading and
refining as opposed to the traditional crude pumped from oil wells.
California Democrat Representative Henry Waxman, chairman of the
House Committee on Oversight and Government Reform and Republican Tom
Davis added the clause.
Uh, right. Since we all burn pure unrefined crude oil pumped right from the oil well in our car.
Here is what a traditional crude oil goes through before it becomes gasoline:
- Water and salt must be removed
- The oil is heated up to over 700 degrees, and is separated into its fractions via distillation. Oil is made up of hydrocarbon chains of many lengths, from short ones (methane, ethane, propane) to very long ones (asphalt, heavy motor oils). Gasoline is somewhere in between.
- Each fraction generally has to be de-sulfurized. This generally occurs by injecting hydrogen into the fraction across a catalyst bed to remove the sulfur as Hydrogen Sulfide, a dangerous gas that must be further processed to produce pure sulfur.
- The gasoline fractions in a typical oil are nowhere near large enough for the relative demand. So additional steps must be taken to produce gasoline:
- Very heavy fractions have their molecules cracked at high temperatures, either in cokers, high temperature crackers or in fluid catalyst bed crackers. These processes either remove carbon in its pure form or remove it by combining it with hydrogen
- Certain fractions are reformed in combination with hyrdrogen, sometimes across a platinum catalyst, to produce molecules with better properties for gasoline, including higher octane.
- All over a refinery, there are small units that take individual fractions that use a variety of processes to create specific molecules that have useful properties
- All of these different fractions and products are blended in various proportions to make different grades of gasoline. These blends and proportions can change from city to city (to meet environmental regulations, Phoenix must have a gasoline blend that is unique in the US) and must change season to season (gas that burns well in winter will vapor lock in the summer time).
I am sure I left tons of steps out, but you get the idea. Below are my old digs at Exxon's Baytown Texas Refinery, where I worked as an engineer for 3 years out of college: