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What Goes into Making Biofuels?

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Energy, Environment, and Everyday Life

Université de l'Illinois à Urbana-Champaign

4.9 (27 notes) | 4K étudiants inscrits

For a sample of what this course will include, see the video "Energy, Environment, and Everyday Life MOOC with University of Illinois Professor David Ruzic" - http://go.citl.illinois.edu/Energy-MOOC This course teaches you everything you need to know about energy, the environment, and at least a number of things in everyday life. It starts by talking about energy itself and where it comes from. This includes how much we have, who has it, who uses it, and what that all means. The video clips are produced in a fast-paced multimedia format during which Professor Ruzic throws in fun and demonstrations. There are multiple-choice questions to check your understanding and some more in-depth exercises to guide you deeper into the subject. After explaining the main things we use energy for – our cars and electronics! – fossil fuels are examined in detail. Want to really learn about fracking or pipelines? Watch these segments. The environmental effects of fossil fuels are taught as well. Global warming, acid rain, and geoengineering all are in this part of the course. Part of their solution is too. Renewables follow, with clips on solar, wind, hydro, geothermal, biofuels, etc. You’ll even see Professor Ruzic in a corn field and in the middle of a stream showing how you could dam it up. Finally, nuclear power is taught in detail – how it really works and what happens when it doesn’t work, as in Three Mile Island, Chernobyl, and Fukushima, as well as how we are making it today, which is shown here without political preconceptions. In this course, economics takes center stage. People will ultimately do whatever costs the least, so energy policy is most effective when it is targeted at the user’s wallet. Throughout the course there are 24 segments on “How Things Work." These guides to everyday life are tremendously varied, covering everything from fireworks to making beer to what happens backstage at a theater. The course is designed to be enjoyable as well as informative. We hope you will take a look!

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À partir de la leçon

Week 5: Renewables – What Is New under the Sun

Renewable energy sources finally make an appearance this week. Here we will tell you about everything powered by the sun directly and indirectly. This includes photo-voltaic, passive solar design, wind, and biofuels. Again, their inner working, what is needed, and how much it costs are the focus. You will see Prof. Ruzic make moonshine and show you how you can, too. “How Things Work” takes you to an actual windmill and brewery, and, just for fun, an ice skating rink.

Making Moonshine7:48

How Things Work: How Is Beer Made?21:07

What Goes into Making Biofuels?21:31

Economics of Biofuels16:43

Growing Stuff to Burn11:36

Energy from Garbage29:41

Enseigné par

David N. Ruzic
Abel Bliss Professor

Transcription

[MUSIC]

So, what are biofuels?

Biofuels are things that we can use for

energy that are made by biological systems.

Most notably, there are two big ones.

Ethanol production, which we can get from greens or

sugar bits and biodiesel.

Diesel fuel you can get from ordinary oils, vegetable oils,

animal oils, things of biological origin.

What is ethanol?

Ethanol's the good stuff.

This is the alcohol you drink,

the things that come out in our whiskey bottle or a beer bottle.

Actually, what it is, is the following molecule.

We have two carbon groups and each of them have a hydrogen,

except to make this one an alcohol,

there's a oxygen and another hydrogen.

This is ethanol.

When you go to gasoline pump, you’ll notice it will say,

may contain up to 10% alcohol.

That is the E10.

E for ethanol, 10 for 10%.

Gasohol is how used to be named and now almost all fuel

in the United States has this 10% alcohol blend.

It becomes an oxygenator, which reduces pollution.

It also allows us to substitute some biofuels for

the otherwise imported oil that we would have to use.

At some gas stations, you will see stuff called E85.

It's 85% ethanol.

Flex fuel vehicles can easily switch between almost 100% ethanol or

100% gasoline.

Both burn very quickly and very well.

So, the difficulty of using one fuel to another is not that hard.

When you go to one of these gas stations,

you might notice that the E85 is always cheaper.

You say, wow, why don't I use it?

Careful, ethanol only has 70% of the energy content of gasoline.

So if you usually get a hundred miles per gallon, probably no one gets that.

Maybe you got a motorcycle.

If you fill it up with 100% ethanol, you'd only get 70 miles per gallon.

What you really need to do is look at the price difference and

see if it's around that three-quarters range, then it's a good deal.

So you might wonder, can we grow ourselves out of an energy crisis?

Do we not have to import oil or use up the oil from the ground,

because we can just grow it.

Not so fast.

Like the world, the US uses an awful lot of gasoline.

This chart shows the different amount of gasoline we use

3.5 billion barrels per year versus the amount of ethanol.

The ethanol is about 10%, about 300 million barrels per year.

And by the way, a barrel is another one of these strange American units

that's equal to 42 gallons and a gallon is another strange American unit that

is actually equal to 3.8 liters.

What you going to do?

Let's focus in on just the blue part.

So if you look at this chart, you can see that

ethanol production in the United States has really ramped up over a period

of the last maybe ten years, but it's reached a plateau.

And that plateau is there, because they don't have all

that much corn and people still want to eat.

Actually, what they want to eat is they want to eat meat.

Significant part of our corn crop goes to feeding animals.

So here is a graphic that shows the division of the corn that is produced

in the United States and where it's used and

you'll notice that the largest single factor is using it for

animal feed, but the amount you see there for ethanol is also pretty big.

Sometimes you'll have people claim, only a quarter of our corn is used.

And other times, you'll have a people say, a third of our corn is used to make fuel.

Well, let's look at this a little more closely.

See a section there, 13% for feed co-products, DDG, dried distillers grain.

Actually, that take a whole third of our corn.

But after you make the alcohol out of it, the stuff that's left can be dried and

once again, fed to the animals.

So, it depends if you want to count that as a third of the corn for fuel or

only two-thirds of it and the rest goes to animal feed.

Notice that there's also a significant export portion.

While maybe we could increase that amount of ethanol we make,

you can notice that there's gotta be some limit.

When you start trading food security for energy security,

you can end up having some problems since you can substitute corn

to make alcohol for oil, but we also used corn for the feed

stocks which are going to go into our meat products, and our milk, and so forth.

You might wonder, is there a correlation in price?

This chart shows that indeed there is.

Notice that when oil prices go up, corn prices go up.

And therefore, food prices go up.

Maybe it's not a perfect correlation, but there are several locations along this

graph where you can see clearly that trend.

So, probably having corn make 10% of our gasoline.

Since we use it in a 10% mixture, it's probably just right,

the right amount about as much as you're going to be able to get out of this

biofuel crop at least in the United States.

You might say, well, that's good.

So, replace it with 10% of our oil.

Well, not so fast.

This particular graph shows the distribution of how oil is used and

where oil is used to make our different fuels.

There's many tires as people in the United States or pretty darn close.

So automobile fuel, gasoline uses about half of the oil.

That's only half.

So really when people say, corn uses 10% of the gasoline,

it's substituting for about 5% of the oil.

Many of these figures you're seeing are from the 2011, 2012.

But as you noticed with the graph on how much ethanol we're making,

these numbers are very flat and continuous to this level about to today.

So let's take another look at that division of how the oil that's comes in,

the crude oil that comes in to the country is unused.

You can see that the next larger used after gasoline is diesel fuel.

Diesel fuels what runs the trucks.

So, can you actually substitute biomass plants for diesel fuel?

Well, indeed you can and it's called biodiesel.

So it means are like a whole food you can use it, you can live off of it,

you can't live off of corn alone.

So, soybeans are very valuable.

It cost mor to make, it cost more to buy, and it have more food value.

But still if you have access, economics whether or

not make senses to turn into diesel fuel.

So looking to this biofuel trends you can see that we use much lest

biodiesel then we do with ethanol.

It turns out that about of all the diesel fuel we use,

4% of it is from biodiesel.

So that means, since diesel fuel is 20% of our oil use,

our crude oil use it's 0.8% of our crude oil is substituted by soy beans.

So if we're using 4% of our diesel fuels from soybeans,

the question is, how many soybeans is that?

Well here, just like with the corn, the answer's a little more complicated.

First off, all soybeans aren't used for oil.

This chart shows you how much goes into the crush.

How much of the soybeans are actually turned into oil.

You can see it's about half, maybe a little more than half.

So, about half of the soybeans are turned into soybean oil.

But, of course, not all of the soybean oil is turned into biodiesel.

This chart shows you that it's about one fifth of the soybean oil

that goes into biodiesel.

So, if we had half of the soybeans make oil.

One fifth of the oil makes diesel fuel.

One fifth times one half that's 10%.

10% of our soybeans are turned into biodiesel fuel.

The cool thing is that you don't need soybean oil to make biodiesel.

In fact, you can make it about out of any biological oil itself.

You can use it of the grease.

You can make it out of chicken fat.

You can go to McDonald's to the fry pans when they make the French fries and

when they're done with it, you can turn that into biodiesel.

There's even how to instructional videos on the web

that will tell you how you can make your own biodiesel generating system.

In fact, it's really not all that hard, let me show you how it's done.

So, how do you take the things growing in those beautiful, green, lush fields.

Soybeans after they dry and take them out of the husks until you get the beans

themselves and turn that into diesel fuel.

That's what I'm going to show you right now.

The first step is that you don't actually use the soybeans.

You need to take the beans.

And actually you won't do this part at home.

You need to crush them.

It's even harder than corn.

And turn it into soybean oil.

100% pure good soybean oil.

Of course, the soybean oil costs more than just going out and buying diesel fuel, so

the real use of this if you get some waste oil.

Get the oil from your fryer, go to your local chicken place and get their oil.

Or course if you do that, you better clean it.

You gotta strain it.

You gotta get all those strange bits of things that are left in the fryer out.

But finally, you're going to end with oil.

Soybeans crushed makes oil.

First step in making biodiesel is you need to heat up the oil.

And you need to worry about the temperature.

So unlike making alcohol from corn you just need to keep

the waters liquid stuff going between 70, 80 and 100c.

Here, we need to heat this up to a particular level,

to get the reaction to take place.

So, I'm going to start with 800

millilitres of soybean oil.

So, we need to heat the oil up to 54 degrees centigrade, 130 Fahrenheit.

Not too far away.

Right now we're at about 40.

Just be a few more minutes depending on the pH of you oil,

you need to add some lime.

Potassium hydroxide.

It turns out for regular oil,

you only need 6.4 grams for 800 millilitres.

So here is my potassium hydroxide.

And this stuff I really do have to crush, all right?

[SOUND] If the pH of your oil is a little different, you can look up on a,

in a biodiesel calculator how much lye you need to add to it.

So now, we add just this right amount of lye.

To the cooking oil.

I may need to stir it.

This will adjust its pH, it's acid level, to just the right amount.

Now we need the other ingredient, methyl alcohol.

Not the kind of alcohol we were making when we did corn that's ethyl alcohol.

This is not the stuff that you can drink.

This is the stuff that actually would make you go blind if you drank it.

We're not distilling liquor here, we're making fuel for buses and

trucks, tractors.

For the 800 millilitres of oil we need 175 millilitres of methanol.

There we go.

Now this is relatively simple chemistry.

And we get a reaction that will actually take oil and

methanol and turn it into two products.

The first is the one we want.

The diesel fuel.

L-canes and cyclic hydrocarbons.

The other product will be glycerin.

Glycerin is fairly thick, all right?

And the glycerine will actually have methanol still stuck with it.

If you're doing this on industrial scale,

you can actually reclaim most of this methanol and use it over again.

So here is the reaction.

So you have to add this slowly.

You add this a little bit at a time.

And you can see how it’s bubbling up.

So, I’m doing this outside, or you do it in a well-ventilated area.

Chemical reaction is slightly exothermic and it’s actually taking place.

It’s also

important not to have the temperature of the oil too high.

because if it's too high, the methanol is simply just going to boil.

I can actually tell that some of the process is happening because the oil is

getting thicker.

Just in case we're at too high a temperature,

I've already turned off the hot plate.

Let me just move it over here.

Just check my temperature again.

Methanol is of course much cooler.

So I'm going to need to add a little bit of heat here.

Well, wasn't that exciting?

Now comes the boring part.

We wait.

We actually use gravity.

The diesel fuel will be lighter than the glycerin.

And it needs to sit here and separate.

Sometimes, it can just take a long time to separate.

However, if you look here closely,

you can start seeing it being much clearer and lighter at the very top.

In time, this layer will continue and the glycerin will be on the bottom

with the excess alcohol, and the diesel fuel on the top.

A proper set up for this would have a drain from the bottom of the tank and

you would drain out the glycerin and the methanol.

At that point, you would boil it.

Well, you would heat it up, to turn the methanol into a vapor, and

recover it from the glycerin.

The glycerin, you can throw away.

Maybe there's a market for it.

The stuff left in your tank is the diesel fuel you can put in your tractor,

truck, or car.

Well, it sounds very romantic.

That we can take all of these deep fryer oil and turn into bio-diesel.

We use so much more of fuel than we do french fries.

Only this tiny little green bar on the graph is the amount of

bio-diesel made from waste oil.

So chemically, what is gasoline?

You might not realize it, but you're told every time you're at

a gasoline pump because there's an octane rating.

An octane, like octopus, means eight.

There are eight carbons in gasoline, in octane.

Gasoline is basically, octane.

The octane molecule has eight carbons in a chain.

One, two, three, four, five, six, seven, eight.

And each of these would have a hydrogen stuck onto it.

So, the chemical formula is C8H18.

Sometimes, the octane is branched,

sometimes it's not in this perfect well in line.

But basically, this is what gasoline is.

Gasoline is dangerous.

Gasoline is extremely volatile.

You can burn things very easily, like this.

Here is gasoline.

Here is diesel fuel.

Diesel fuel is not even lighting.

In fact that exactly shows the point.

The only reason the sticks burning is because I put gasoline on the stick.

Finally, I might get the straw hat to burn.

But it shows a pretty dramatic difference between why diesel fuels,

relatively safe stuff, gasoline, it's a bomb.

When you distill crude oil, you refine it and in that process,

you can get the lighter hydrocarbons off, the gaseous one then the gasoline.

The next thing to come off is the diesel fuel.

Diesel is a little heavier than octane.

In fact, about three quarters of diesel fuel are the slightly heavier elcanes.

Maybe instead of eight carbons, you've got ten or

12 plus that many hydrogens.

That'd be 22 or 26.

That molecule naftulin, is another part of what is in diesel fuel itself.

So 75% of diesel fuel are these just longer chains like gasoline.

Things with ten carbons, 12 carbons off in that range.

The other quarter are siclet hydrocarbons.

Places where the carbon atoms go in a ring.

Most common one of these,

where there are simply six carbons in a ring with alternating single and

double bonds, and hydrogens coming out of each of these is benzene.

It's pretty light weight, probably not too much of that in diesel fuel.

But if we add another methyl group here, protalelene or

a second one maybe down here, rizylene.

These indeed are parts and components of diesel fuel.

Likewise, if you have two carbon rings that are joined, all right?

[INAUDIBLE] Hexagons, right?

This is naphthalene, one of the cyclic hydrocarbons in diesel fuel.

And that's what you need to know.

[MUSIC]

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