WEBVTT

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Just a minute ago,

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this oil helped make a delicious meal possible.

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But now, it's just some nasty goop.

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What should we do with it?

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Well, the easiest thing would be

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to pour it down the drain;

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that makes it seem like it's gone,

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but it's not really gone.

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Instead, it's collecting bits of food

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and other random stuff,

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producing monstrous, greasy blockages

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that clog not only your own drain

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but entire sewage systems,

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causing flooding and pollution.

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Many places have laws for proper disposal of grease,

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but we can go one step further.

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Instead of just throwing it away safely,

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we can turn it into something useful.

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And if you're wondering

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what anyone could possibly want

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with a bunch of digusting, used cooking oil,

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the answer is: biodiesel.

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You've probably heard of diesel engines.

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They power farming and construction equipment,

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trucks, buses, ships, trains, backup generators,

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and even some cars.

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Most of the fuel that feeds these engines

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is refined from petroleum,

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which comes from long-dead dinosaurs

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and other ancient fossils.

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But diesel fuel can also be derived from

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more recently-dead organisms,

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like plants and animals.

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And this type of fuel is what we call biodiesel.

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Biodiesel is a biodegradable energy source,

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made from plant oils or animal fats,

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that can usually be burned in regular diesel engines.

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You guessed it,

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it's the 'bio' version of diesel.

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It's cleaner than normal diesel,

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so there has been a push to generate it

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from crops like soybeans.

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Now, growing plants for fuel,

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instead of food, comes with its own problems.

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But fortunately, we already have some oils and fats right here.

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Preparing your used cooking grease for recycling

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is easy.

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First, let it cool down to room temperature.

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Then, transfer it to a clean container.

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You can use any old bottles you have lying around,

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like milk jugs,

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as long as they're completely empty,

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rinsed, and dried.

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Use a funnel to avoid spills

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and a sieve to filter out any small food particles.

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You can even add bacon grease

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and other animal fats

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or the excess oil from canned food,

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like tuna or sardines,

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just make sure it's really oil and not brine.

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So, what happens now that your oil is safely contained?

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Well, many cities have recycling services

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that will pick up large amounts of grease

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from restaurants and other establishments.

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But there are locations

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where individuals can drop off their containers, as well.

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All of this grease will end up at a processing plant,

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where it can be converted to useable biodiesel.

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How does this conversion work?

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Well, all these oils and fats you donated

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are made up of triglycerides,

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a glycerol molecule connected to

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three fatty acid chains.

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To convert fats to fuel,

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they react with an alcohol,

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usually methanol or ethanol,

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which produces long-chain esters and glycerol.

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To compare, here are some molecules

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of regular diesel fuel.

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Now, here are the molecules we created

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by breaking apart the triglycerides.

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Glycerol is the odd man out,

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so it's removed at the end of the process.

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But look at these esters!

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If you squint, their structures look pretty similar

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to those of the long-chain hydrocarbons in regular diesel.

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And diesel engines, with a few small modifications,

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can also be made to squint

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and burn these esters like regular diesel fuel.

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Et voila! Biodiesel.

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Now, you might be wondering whether all this hassle

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over recycling used cooking oil

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is even worth it.

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After all, how much energy can it possibly generate?

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Well, if all the grease that New Yorkers throw away in one day

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were converted to jet fuel,

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it would be enough to power several hundred flights

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from New York to Los Angeles.

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And let's not forget that using waste oil

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instead of burning more fossil fuels

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will limit our negative effects on the environment.

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Recycling used cooking grease

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turns goop into good.

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By contributing a little bit,

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individuals and businesses can help create

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an alternative, stable source of diesel oil,

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while protecting the environment

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and keeping our cities cleaner.

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And that's pretty slick.