When hearts attack, or “E(xplianing thanol)”

Tofurkey tastes like crap, but high cholesterol can mean a plate of veggie burgers. On a macro scale, mother earth has spiraling cholesterol, will almost certainly have a heart attack, and must start munching tofu dogs and veggie burgers today. They may not taste great, but who wants England to have another ice age? Read on.

While fluctuating gas costs make drivers think about the relationship of money to gasoline and the “cost” of driving, there are some interesting fixed relationships (read: environmental costs) which stay true no matter if the gas costs 12 cents per gallon (as it does in Caracas) or $6.50, like in the Netherlands (CNN). When a gallon (varies from 5.8 – 6.5 lbs, compared to 8.33 lbs for water) of gas is burned, the composition of the air used in combustion is drastically changed. Gasoline’s chemical structure varies slightly from gallon to gallon (and there are winter and summer blends), but it is basically thousands of carbon chains which have hydrogen atoms all down their sides (C8H18). Burn it with air, and you get carbon dioxide (and water). Well, it is easy to see where the carbon comes from, but the “dioxide” and “O” in H2O comes out of the air—it takes 21 pounds of oxygen to burn one gallon of gas. Goodbye oxygen. Here’s what’s going on (terrapass).

6.25 pounds of gasoline
21 pounds of oxygen


19.3 pounds of carbon dioxide
roughly 8 pounds of water vapor.

Lets say you put 15 gallons of gas in your car when you fill it up. That’s 94 pounds of gasoline. When all the gas is burned, 315 pounds of oxygen has been combined with the gasoline to form 289 pounds of CO2 and 120 pounds of water vapor (which is also a greenhouse gas). Over the course of the year, if a car goes 10,000 miles and gets 25 mpg… it will emit 7720 lbs of CO2, almost certainly more than twice the weight of the car itself. Furthermore, it takes over than 8000 lbs of oxygen gas from our atmosphere.

Is that a lot? I don’t know. Haven’t yet figured out how much oxygen a human turns into carbon dioxide per year through breathing, but I know I’d rather do it than have a car do it for me.

Now it gets weird--everybody knows there are vegetable substitutes for delicious high-cholesterol foods? They can make diesel and gasoline out of vegetables too!

Biodiesel is tofu-diesel and ethanol is tofu-gas. Lets focus on ethanol. Just like tofu-everything, there are tradeoffs, but they are reasonable. Yes, cars must be modified a tiny bit to run on ethanol, but the main issue is that there are only 80 % as many Calories per gallon in ethanol as in gasoline, which leads to a similar reduction in fuel economy.

People get all excited about ethanol because it means we don’t have to be dependent on foreign oil, but the chemically exciting part of ethanol is the history of the carbon inside it. Like gasoline, when ethanol burns a whole bunch of oxygen gets converted into a whole bunch of CO2--the very same CO2 which is formed by burning fossil fuels. What gets interesting is the history of the carbon—in gasoline, the carbon is from fossils and has been stored as oil for millions of years. In ethanol, the carbon is from the atmosphere, removed by the corn as it grew and is then stored in the ethanol. So it’s the same carbon, except that cars running on ethanol become part of the continuing carbon cycle, rather than just releasing hundreds of tons of "new" carbon into the air.

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