0:00:07.089,0:00:08.455
Just a minute ago,

0:00:08.455,0:00:11.246
this oil helped make a delicious meal possible.

0:00:11.246,0:00:13.794
But now, it's just some nasty goop.

0:00:13.794,0:00:15.045
What should we do with it?

0:00:15.045,0:00:16.329
Well, the easiest thing would be

0:00:16.329,0:00:17.495
to pour it down the drain;

0:00:17.495,0:00:19.495
that makes it seem like it's gone,

0:00:19.495,0:00:20.579
but it's not really gone.

0:00:20.579,0:00:22.913
Instead, it's collecting bits of food

0:00:22.913,0:00:24.413
and other random stuff,

0:00:24.413,0:00:26.639
producing monstrous, greasy blockages

0:00:26.639,0:00:28.516
that clog not only your own drain

0:00:28.516,0:00:30.352
but entire sewage systems,

0:00:30.352,0:00:33.259
causing flooding and pollution.

0:00:33.259,0:00:36.606
Many places have laws for proper disposal of grease,

0:00:36.606,0:00:39.236
but we can go one step further.

0:00:39.236,0:00:41.068
Instead of just throwing it away safely,

0:00:41.068,0:00:43.114
we can turn it into something useful.

0:00:43.114,0:00:44.176
And if you're wondering

0:00:44.176,0:00:45.650
what anyone could possibly want

0:00:45.650,0:00:47.817
with a bunch of digusting, used cooking oil,

0:00:47.817,0:00:50.067
the answer is: biodiesel.

0:00:50.067,0:00:52.205
You've probably heard of diesel engines.

0:00:52.205,0:00:54.567
They power farming and construction equipment,

0:00:54.567,0:00:58.210
trucks, buses, ships, trains, backup generators,

0:00:58.210,0:00:59.983
and even some cars.

0:00:59.983,0:01:01.798
Most of the fuel that feeds these engines

0:01:01.798,0:01:03.401
is refined from petroleum,

0:01:03.401,0:01:05.429
which comes from long-dead dinosaurs

0:01:05.429,0:01:07.263
and other ancient fossils.

0:01:07.263,0:01:09.266
But diesel fuel can also be derived from

0:01:09.266,0:01:10.816
more recently-dead organisms,

0:01:10.816,0:01:12.269
like plants and animals.

0:01:12.269,0:01:14.744
And this type of fuel is what we call biodiesel.

0:01:14.744,0:01:18.106
Biodiesel is a biodegradable energy source,

0:01:18.106,0:01:20.443
made from plant oils or animal fats,

0:01:20.443,0:01:23.566
that can usually be burned in regular diesel engines.

0:01:23.566,0:01:24.598
You guessed it,

0:01:24.598,0:01:26.649
it's the 'bio' version of diesel.

0:01:26.649,0:01:28.149
It's cleaner than normal diesel,

0:01:28.149,0:01:30.066
so there has been a push to generate it

0:01:30.066,0:01:32.039
from crops like soybeans.

0:01:32.039,0:01:33.817
Now, growing plants for fuel,

0:01:33.817,0:01:36.168
instead of food, comes with its own problems.

0:01:36.168,0:01:40.900
But fortunately, we already have some oils and fats right here.

0:01:40.900,0:01:42.483
Preparing your used cooking grease for recycling

0:01:42.483,0:01:43.842
is easy.

0:01:43.842,0:01:46.233
First, let it cool down to room temperature.

0:01:46.233,0:01:48.484
Then, transfer it to a clean container.

0:01:48.484,0:01:50.513
You can use any old bottles you have lying around,

0:01:50.513,0:01:51.816
like milk jugs,

0:01:51.816,0:01:53.183
as long as they're completely empty,

0:01:53.183,0:01:54.815
rinsed, and dried.

0:01:54.815,0:01:56.479
Use a funnel to avoid spills

0:01:56.479,0:01:59.568
and a sieve to filter out any small food particles.

0:01:59.568,0:02:01.026
You can even add bacon grease

0:02:01.026,0:02:02.193
and other animal fats

0:02:02.193,0:02:03.278
or the excess oil from canned food,

0:02:03.278,0:02:05.863
like tuna or sardines,

0:02:05.863,0:02:08.566
just make sure it's really oil and not brine.

0:02:08.566,0:02:11.369
So, what happens now that your oil is safely contained?

0:02:11.369,0:02:13.955
Well, many cities have recycling services

0:02:13.955,0:02:15.817
that will pick up large amounts of grease

0:02:15.817,0:02:17.874
from restaurants and other establishments.

0:02:17.874,0:02:18.960
But there are locations

0:02:18.960,0:02:21.754
where individuals can drop off their containers, as well.

0:02:21.754,0:02:24.131
All of this grease will end up at a processing plant,

0:02:24.131,0:02:27.428
where it can be converted to useable biodiesel.

0:02:27.428,0:02:29.173
How does this conversion work?

0:02:29.173,0:02:31.722
Well, all these oils and fats you donated

0:02:31.722,0:02:33.483
are made up of triglycerides,

0:02:33.483,0:02:35.066
a glycerol molecule connected to

0:02:35.066,0:02:37.315
three fatty acid chains.

0:02:37.315,0:02:38.898
To convert fats to fuel,

0:02:38.898,0:02:40.523
they react with an alcohol,

0:02:40.523,0:02:42.483
usually methanol or ethanol,

0:02:42.483,0:02:45.484
which produces long-chain esters and glycerol.

0:02:45.484,0:02:47.484
To compare, here are some molecules

0:02:47.484,0:02:49.149
of regular diesel fuel.

0:02:49.149,0:02:51.483
Now, here are the molecules we created

0:02:51.483,0:02:53.452
by breaking apart the triglycerides.

0:02:53.452,0:02:55.317
Glycerol is the odd man out,

0:02:55.317,0:02:57.816
so it's removed at the end of the process.

0:02:57.816,0:02:59.500
But look at these esters!

0:02:59.500,0:03:01.798
If you squint, their structures look pretty similar

0:03:01.798,0:03:05.590
to those of the long-chain hydrocarbons in regular diesel.

0:03:05.590,0:03:08.067
And diesel engines, with a few small modifications,

0:03:08.067,0:03:10.567
can also be made to squint

0:03:10.567,0:03:14.014
and burn these esters like regular diesel fuel.

0:03:14.014,0:03:16.093
Et voila! Biodiesel.

0:03:16.093,0:03:18.586
Now, you might be wondering whether all this hassle

0:03:18.586,0:03:20.233
over recycling used cooking oil

0:03:20.233,0:03:21.898
is even worth it.

0:03:21.898,0:03:24.983
After all, how much energy can it possibly generate?

0:03:24.983,0:03:28.899
Well, if all the grease that New Yorkers throw away in one day

0:03:28.899,0:03:30.783
were converted to jet fuel,

0:03:30.783,0:03:33.701
it would be enough to power several hundred flights

0:03:33.701,0:03:35.869
from New York to Los Angeles.

0:03:35.869,0:03:37.816
And let's not forget that using waste oil

0:03:37.816,0:03:39.816
instead of burning more fossil fuels

0:03:39.816,0:03:43.066
will limit our negative effects on the environment.

0:03:43.066,0:03:44.706
Recycling used cooking grease

0:03:44.706,0:03:46.529
turns goop into good.

0:03:46.529,0:03:48.131
By contributing a little bit,

0:03:48.131,0:03:49.969
individuals and businesses can help create

0:03:49.969,0:03:52.444
an alternative, stable source of diesel oil,

0:03:52.444,0:03:53.945
while protecting the environment

0:03:53.945,0:03:55.682
and keeping our cities cleaner.

0:03:55.682,0:03:59.682
And that's pretty slick.