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Monday, June 28, 2004

What if crude was part of the Atkin's diet?

An interesting bit of trivia that blows my mind.

Petroleum contains about 33,000,000 joules/liter.
This is equivalent to 39,000 calories/teaspoon.

The average well-fed human requires 2500 dietetic calories of energy per day to thrive.

So, if petrol was edible and humans could metabolize the energy within it, humans would only need about 1/16th of a teaspoon per day to satisfy their caloric intake. insert SANITY CHECK here: times 1000 to convert from dietetic calories, so actually about 1-1/3 cups

The smallest measuring utensil I own doles out 1/8th teaspoon at a time; cooks refer to half of this amount as "a pinch".

Think about that the next time you (1) look at a crop field, (2) eat a bowl of cereal, or (3) flush your toilet.

UPDATE: This post was a load of crap (for me to poop on!) because of poor dimensional analysis. Thanks to DarkSyde for pointing this out. What it does now show is how the energy content of vegetable oil is similar to petroleum. The sanity check is that people could probably survive for awhile consuming a cup of vegetable oil per day, but they could not by consuming only 1/8 a teaspoon. I also have a better appreciation now for the "greasel" enthusiasts.

What’s the old quote about wisdom being gained from experience and experience is gained from mistakes?


Professor Blogger DarkSyde said...

Are you sure about that Webster? I think you might be confusing a calorie as used in physics/chem, with a calorie as in dieting. I'm not certain, but the dieting 'calorie' is I believe 1000 actual calories and for some bizare reason they never mention that it's a kilocal anymore when talking about food. I could be quite wrong, but check it out.

10:14 AM  
Professor Blogger WHT said...

Yea, I should have done a sanity check. Since vegetable oil can be used to run a car, the energy contained within it should be comparable to gasoline. Sure enough, if I multiply 1/16 by a thousand, you get over a cup. I can imagine people being able to survive by eating a cup of vegetable oil a day, but not 1/16th of a teaspoon.

2:49 PM  
Professor Blogger DarkSyde said...

Well you still have a very good point though. I never thought about it in terms of human consupmtion. But you're right, oil, petrol, and condensate, packs a hell of a wallop, enthalpy wise.
And my guess would be that even diesal would pack more per unit volume than vegetable oil. This is something that is hard to get across to people who lack basic physical science and criticize the use of oil products over synthohol. We use oil over alcohol and other flagellate for a reason. It's cheaper, and it provides more work per unit volume. Basically, it burns hotter than alcohol so you can expand more air, heat more water, in effect do more mechanical work.

I'd be willing to bet a human could be sustained on a quarter cup or so, assuming it could be effeciently metabolized into some kind of 'deviant' Krebs Cycle. Great Blog BTW, I really enjoy your perspective and expertise.

5:19 PM  
Professor Blogger WHT said...

Thanks for the comments. And to to top it off, as you imply, we have the effective energy content of biofuel; in which we have to subtract the energy that went into processing the veggies and such.

10:41 PM  

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