Organic Material And Oil

November 19th, 2012
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How much organic matter is needed to create a gallon of crude oil (petroleum)? Literally a truckload – actually, many truckloads.

I was refueling  my ATV the other day and marveling at how far a liter of petrol (gas) carried me, Niki the Wonder Dog and some gear across some reasonably rough terrain. The environmental issues aside, I still find the amount of work a small amount of this liquid can do to be mind-boggling.

I’m also fiddling with an electric ATV, using solar power to charge the batteries. It takes around 8 hours for 260 watts of solar panels to charge it enough to give me 18 kilometers range, at less speed and carrying less. However, it’s not a very efficient charging system I’m using and the ATV is just a petrol version that has been somewhat crudely converted.

There’s an awful lot of energy stored in crude oil – which is one of the reasons we’re having troubles getting away from the stuff. It’s certainly very compact compared to the batteries I’m using. Of course, the electric ATV is a lot quieter and cleaner though; but anyway, that’s another topic for another time.

As you probably know, crude oil comes from plants and marine organisms that existed many hundreds of thousands of years ago. Dead dinosaurs may also have contributed matter, but it’s believed that it would only equate to a small percentage.

The most popular theory is that as organisms died, they piled up at the bottom of bodies of water and mixed with sediment. As the sediment accumulated, the intense heat and pressure generated turned this organic material into a substance called kerogen. Over time, this kerogen breaks down and becomes natural gas or petroleum.

So, how much of the original organic material is needed to make a gallon of oil?

Around 98 tons of it! That’s according to some old figures I dug up on the California Energy Commission web site, attributed to ecologist Jeff Dukes.

Mr. Dukes said the amount of plant material that went into the fossil fuels we burned since the mid 1700′s was equal to all the plants grown on Earth over 13,300 years (and that figure is over a decade old).

Think about some of the long trips you’ve taken or even how much gas you pump into your vehicle each week. Bearing in mind a gallon of oil produces up to 0.67 gallons of gasoline; my weekly figure (including my main vehicle usage) is around 9 gallons of crude oil equivalent. That translates to around 880 tons of ancient organic material a week or 45,760 tons of the stuff a year.

But it’s more than that – most of the goods and services we purchase have been trucked in from somewhere, so that adds to our fuel consumption.

What about biofuels?

Generally, biofuels are very land intensive and still require a great deal of material. The following are figures I found on the University of Missouri’s web site.

1 acre of corn harvested in 2012:
158.6 bushels of corn per acre
2.77 gallons of ethanol per bushel (56lbs each) of corn
439 gallons of ethanol per acre

1 acre harvested of sugar beets harvested in 2012:
23 tons of beets per acre
24 gallons of ethanol per ton of beets
552 gallons of ethanol per acre

1 acre of harvested soybeans in 2012
42.8 bushels of soybeans per acre
11.28 pounds of soybean oil per bushel (60lbs each) of soybeans
7.7 pounds of unrefined soybean oil per gallon of biodiesel
63 gallons of biodiesel per acre

1 acre of harvested canola in 2012
1557 pounds of canola per acre
0.383 pounds of canola oil per pound of canola
7.7 pounds of unrefined canola oil per gallon of biodiesel
77 gallons of biodiesel per acre

The above figures are just for the feedstock used to make biofuel – not the whole plant; and then there’s the resources that go into turning the feedstock into fuel. Granted, the waste and by-products can often be used in other applications.

Keeping these sorts of stats in mind (aside from just being interesting trivia) can help remind us how hard the earth has to work to provide us with resources – and that some of those resources are being used up far faster than Mother Nature can provide them; not to mention the damage we wreak through heavy usage.

Also, when we start using food crops as fuel or diverting agricultural land to fuel production, it’s a little frightening – the practice has been labeled a crime against humanity. However, another ancient petroleum source mentioned, algae, is showing promise in terms of cultivation and biofuel production. Other promising feedstocks that can be grown on marginal land includes switchgrass and industrial hemp.

Personally, I’m still looking forward to an all electric 4×4 with a reasonable range (and at a reasonable price); but I think I’ll need a few more solar panels :).

Bonus trivia:

Fossil fuels are a form of converted solar power (albeit a dirty form) – as without the sun the many ancient forms of algae and plants couldn’t have grown.


Gas saving tips

Michael Bloch
Green Living
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