Placeholder Image

字幕表 動画を再生する

  • PLASTIC IS EVERYWHERE.

  • FROM THE CAMERA RECORDING ME RIGHT NOW,

  • TO THE DEVICE YOU'RE WATCHING THIS ON,

  • THE CLOTHES THAT WE'RE WEARING

  • THE GALLON OF MILK YOU DRANK  STRAIGHT OUT OF THIS MORNING,

  • AND THE FRIDGE THAT YOU POPPED IT BACK INTO...

  • WHICH IS GROSS, BY THE WAY.

  • BUT THAT'S BECAUSE IT'S A PRETTY AWESOME INVENTION.

  • PLASTIC IS FLEXIBLE, DURABLE, TUNABLE,

  • AND IT'S CHEAP.

  • BUT FOR ALL OF PLASTIC'S SUPERPOWERS,

  • IT AS AN OBVIOUS DARK SIDE.

  • IT HAS A MASSIVE CARBON FOOTPRINT, WREAKS HAVOC ON OUR NATURAL ECOSYSTEMS, AND IS SO

  • PERVASIVE THAT IT'S LITERALLY SHOWING UP IN THE FOOD WE EAT AND AIR THAT WE BREATHE.

  • SOME WOULD ARGUE THAT WE JUST NEED TO QUIT PLASTIC COLD TURKEY.

  • BUT BECAUSE WE'RE SO WRAPPED UP IN IT,

  • THAT MIGHT BE EASIER SAID THAN DONE.

  • BUT WHAT IF WE COULD UPGRADE TO SOMETHING BETTER?

  • HOW CLOSE ARE WE TO REINVENTING PLASTIC?

  • THE LIFE CYCLE OF MOST PLASTICS STARTS WITH

  • PETROCHEMICALS, WHICH ARE USED TO FORM SOME KIND OF SOURCE MATERIAL, LIKE THESE PELLETS

  • CALLED….

  • I KID YOU NOT

  • 'NURDLES.'

  • - So you can have these plastic pellets that get melted into something like plastic packaging

  • for instance, or maybe it gets blow molded into a water bottle...

  • that bottle might go somewhere else, where a label gets put on top of it,

  • where it goes somewhere else, where it gets filled.

  • - Plastics are polymers.

  • "Poly" means many, and "mers" means parts.

  • So, basically small molecules which are chained together to make a really large molecule,

  • or a macromolecule.

  • Some of these macromolecules can be shaped using heat and pressure

  • And that's what plastics are.

  • So you can start with ethylene gas, you polymerize

  • into polyethylene, which is a plastic.

  • And you can use it in various shapes and forms.

  • POLYETHYLENE IS JUST ONE OF COUNTLESS TYPES

  • OF PLASTICS WITH DIFFERENT PROPERTIES,

  • EACH PERFECTLY SUITED FOR THEIR APPLICATION,

  • FROM SEALING A HOUSE, TO LINING A CAR

  • SHIPPING A PRODUCT, WRAPPING PRODUCE,

  • KEEPING YOUR SODA CARBONATED

  • OR YOUR CLOTHING FROM CRUMBLING INTO A MILLION PIECES WHEN YOU SWEAT.

  • (WHICH IS A DIFFERENT TYPE OF VIDEO).

  • Packaging is the largest consumer of polymers, or plastics.

  • We are interacting with them every day.

  • AND THAT'S ONE MAJOR CHALLENGE OF RE-INVENTING PLASTIC.

  • IT'S FINDING A REPLACEMENT THAT CAN DO ALL THESE THINGS.

  • A MIRACLE MATERIAL WHICH POSSESSES ALL THE INCREDIBLE PROPERTIES OF PLASTIC,

  • BUT IS STILL SUSTAINABLE TO PRODUCE, USE, AND DISPOSE OF,

  • MEANING IT'S BOTH BIO-BASED AND BIODEGRADABLE.

  • - Bio-based is, where does the carbon in the material come from?

  • Is it rapidly renewable?

  • So, if it's rapidly renewable, bio-based carbon, is it from plants?

  • Is it from waste bio-gas?

  • Biodegradable is what happens to a material at end of life.

  • Can it be prone to enzymatic attack by microorganisms, by bacteria, by fungi?

  • Can they break it down and convert it into something else?

  • - PLA is polylactic acid.

  • It's one of the plastics which is bio-derived, biodegradable, and compostable.

  • RIGHT NOW, PLA IS THE MOST WIDELY AVAILABLEBIOPOLYMERON THE MARKET.

  • AND YOU MIGHT ALREADY BE FAMILIAR WITH IT

  • FOR BETTER OR WORSE.

  • - People always say, "Oh, I know what you're talking about! I used it in my straw

  • in my coffee yesterday and it turned to a wet noodle."

  • But one of the other bigger challenges is PLA generally will only break down in

  • industrially compostable environments.

  • It needs high heat and high pressure.

  • INDUSTRIAL COMPOSTING IS A CHALLENGE FOR THE

  • SAME REASON THAT RECYCLING IS: IT'S EXPENSIVE, BUT NOT PROFITABLE RIGHT AWAY;

  • IT REQUIRES MASSIVE INFRASTRUCTURE TO BE BUILT FROM THE GROUND UP;

  • AND IT DOESN'T CATCH ANYTHING THAT DOESN'T JUST WALTZ THROUGH ITS DOOR.

  • SO, IF YOU THROW A RECYCLABLE SODA BOTTLE IN THE WRONG BIN OR A 'COMPOSTABLE' PLA CUP

  • IN YOUR BACKYARD, THE PLASTIC IS STILL STUCK.

  • IT'S NOT GOING TO GET BROKEN DOWN.

  • THAT'S WHY MOLLY AND HER TEAM AT MANGO MATERIALS

  • ARE FOCUSED ON A DIFFERENT KIND OF BIOPOLYMER.

  • ONE THAT DEGRADES NATURALLY, BUT ONLY WHEN YOU WANT IT TO...

  • AND ROLLS OFF THE TONGUE:

  • POLYHYDROXYALKANOATES.

  • - Polyhydroxyalkanoates are a family of naturally occuring biopolyesters.

  • It's the way bacteria have evolved over billions of years to store carbon in case

  • of famines coming.

  • PHAs were identified in bacteria over a hundred years ago.

  • The challenge has been how to commercialize them.

  • TYPICALLY, USING BACTERIA TO PRODUCE PHA IN THEIR CELL WALLS

  • REQUIRED FEEDING THEM SOMETHING LIKE SUGAR OR VEGETABLE OILS.

  • BUT BECAUSE THOSE ARE AGRICULTURAL PRODUCTS, THE PROCESS CAN BE DIFFICULT AT BIG SCALES.

  • BUT OVER A DECADE AGO, MOLLY AND HER RESEARCH TEAM AT STANFORD

  • STARTED TO TOSS AROUND ANOTHER IDEA

  • ONE THAT HAS SINCE BECOME REVOLUTIONARY.

  • What if instead, we used methane?

  • There's naturally occurring methanotrophs, or bacteria that can consume methane,

  • and could they produce PHA?

  • It would make sense that they could because this is an ancient carbon storage mechanism

  • in organisms.

  • I'd say that was the Eureka moment if there was one,

  • and now there's just been continual sort of successes as we validate,

  • can you use waste methane?

  • What kind of properties can you get from compounding or formulating the polymer correctly?

  • How do you scale up?

  • AND THAT'S BEEN THE MAJOR CHALLENGE FOR

  • ANY KIND OF NEXT-GENERATION MATERIAL TO BE ABLE TO COMPETE WITH

  • PETROLEUM-BASED PLASTIC PRODUCTS.

  • - If you go to a dollar store, you see items which are about $1.

  • So the product by itself has to be less than $1, along with the package.

  • So the package has to be relatively very, very cheap

  • in order to succeed in the market.

  • TO DRIVE A COMPETING MATERIAL'S COSTS DOWN THAT FAR,

  • IT WOULD HAVE TO BE SO EASY TO PRODUCE THAT IT WOULD BE LIKE

  • PULLING IT OUT OF THIN AIR.

  • AND ACCORDING TO MANGO, THAT THIN AIR IS THE DELICIOUS SMELL OF METHANE,

  • WAFTING FROM THE LANDFILLS AND WASTEWATER TREATMENT PLANTS

  • RIGHT IN OUR BACKYARD.

  • - We're able to pipe right off of the existing infrastructure

  • that they have here.

  • The tank that you see behind me here is called

  • an anaerobic digester.

  • And that is where there's organisms called methanogens that live there and eat the waste,

  • and actually produce methane, hence the name "methanogen."

  • Behind me, we have the fermentor where the

  • bacteria live, grow, and make the biopolymer.

  • It actually happens in two stages.

  • So the first, we call reproduction, where we actually want the organisms to double, and

  • then, we actually want all of those millions of organisms to transform, which means to

  • take that carbon and build up the biopolymer, polyhydroxyalkanoate, inside of cell walls,

  • Once they are fat and happy, we basically have to pull the polymer out of their cell

  • walls through the harvesting step.

  • We remove the cell mass, as we don't need that part - we really want the powder,

  • which is actually in step six where we've removed the water, and you're left with the powder.

  • But in order for it to be turned into various products,

  • it needs to generally be in pellet form,

  • which is step seven.

  • - If we want to look at what the utopian future could be, in my book, it would be anaerobic

  • digestion to materials, to fuels, to energy.

  • So, we could take these local, decentralized, already-existing facilities - they're already

  • collecting some form of waste. They can anaerobically digest it to methane.

  • Then we are dealing with our waste onsite.

  • And not only that, we are creating a more resilient economy, because we can actually

  • use this material, that's seen as a waste, as a feedstock to the

  • everyday materials and products we need.

  • FOR MOLLY AND HER TEAM TODAY, THOSE PRODUCTS ARE

  • FIBERS FOR TEXTILES, SMALL PACKAGING ITEMS, AND EVEN 3D-PRINTED TOOLS

  • FOR USE IN SPACE.

  • BUT BY SLOWLY BUILDING DEMAND AND IMPROVING THEIR PRODUCTION PROCESS, THEY BELIEVE THAT

  • SOON THEY'LL BE ABLE TO WORK WITH SOMETHING LIKE PLASTIC BAGS.

  • One of the amazing things about PHAs is they

  • can be tailored for lots of different applications.

  • So you can get different properties, whether it's mechanical properties, processing, or

  • even end-of-life biodegradability properties.

  • PHAs can also biodegrade in your backyard

  • compost, so home compost, or even environments where no oxygen is present.

  • It could give producers and other people in the value and supply chain reassurance that

  • it won't be polluting indefinitely for hundreds or thousands of years.

  • SO IF ALL WE NEED TO DO IS MENTOR SOME METHANE-MUNCHING

  • MICROBES TO PRODUCE PHA AT SCALE USING WASTE FACILITIES ALL OVER THE WORLD, GRADUALLY BUILD

  • THE CAPACITY WE NEED TO COMPETE WITH PETROCHEMICAL PLASTICS,

  • AND SIT BACK AND WATCH AS OUR LANDFILLS BECOME GOLD MINES,

  • HOW CLOSE ARE WE TO RE-INVENTING PLASTIC?

  • - We are having a technological leap forward.

  • So the technology of the next generation of plastics is already here;

  • and it's the infrastructure that we have to develop around it.

  • Whether it's bioplastics, compostable plastics, or whether it is processing

  • once the infrastructure is in place, we'll have the next generation of plastics taking over.

  • - So, we're very close to replacing petroleum and polluting plastics.

  • These materials are already here.

  • If everything just fell into place, we'd be looking at single digit years to get there.

  • There's a sweet spot between technology and economics.

  • Packaging and plastics play a very important role in the success of the supply chain.

  • Sustainable plastics, they are going to grow from here on - there's no doubt about that.

  • So once the cost of the production, the infrastructure lines up

  • I see a very bright future for the bioplastics out there.

  • Methane might stink, but our YouTube channel sure doesn't.

  • Make sure to subscribe for all your science news

  • check out our website at Seeker.com, our Instagram, @Seeker, our Facebook, /SeekerMedia,

  • and, for more about plastic, check out this episode of Elements

  • where we cover a team trying to pull it all out of the Pacific Ocean.

  • It's a lot of work.

  • Anyway, thanks for watching!

  • See ya next time!

PLASTIC IS EVERYWHERE.

字幕と単語

動画の操作 ここで「動画」の調整と「字幕」の表示を設定することができます

B1 中級

プラスチックの再発明にどれだけ近づいているか? (How Close Are We to Reinventing Plastic?)

  • 2 1
    林宜悉 に公開 2021 年 01 月 14 日
動画の中の単語