Level 1 — Absolute Beginner
Plastic waste is a big problem. Most plastic is hard to recycle because it must be sorted into different types first.
Scientists at UCLA and a university in South Korea found a new way to solve this problem. They can turn a mix of plastics into clean fuel.
The fuel is called hydrogen. It does not need the plastic to be sorted first, which saves a lot of time and work.
The new process also traps the carbon dioxide gas so it does not go into the air. This could help the planet.
- plastic
- a light, human made material used in many everyday products
- waste
- material that is thrown away because it is no longer needed
- recycle
- to process used materials so they can be used again
- sort
- to arrange things into different groups
- scientist
- a person who studies and does experiments to learn about the world
- fuel
- a material burned or used to produce energy
- hydrogen
- a very light gas that can be used as clean fuel
- planet
- a large body in space, like Earth, that orbits a star
Level 2 — Elementary
Recycling plastic is often difficult because different types of plastic, such as bottles, bags, and containers, normally have to be sorted before they can be processed, which makes the whole system slow and expensive.
Researchers at UCLA's Samueli School of Engineering, working with Ewha Womans University in South Korea, have developed a chemical process that can convert a mixture of the three most common plastics directly into hydrogen fuel.
The process, called alkaline thermal treatment, uses a chemical called sodium hydroxide combined with heat to break the plastics down, producing hydrogen gas that is more than 90 percent pure.
Unlike many recycling methods, this process also locks the carbon released from the plastic away as a solid mineral, rather than letting it escape into the atmosphere as a greenhouse gas.
- process
- a series of actions taken to achieve a particular result
- mixture
- a combination of different things put together
- convert
- to change something into a different form
- alkaline
- having properties opposite to acid; basic in chemistry
- sodium hydroxide
- a strong chemical compound used in industrial processes
- purity
- the state of being free from other substances or impurities
- escape
- to get free or get out of a place
- greenhouse gas
- a gas that traps heat in the atmosphere and contributes to warming
Level 3 — Intermediate
Plastic recycling has long been constrained by the need to sort mixed waste streams into distinct polymer types before processing, a labor intensive step that raises costs and limits how much plastic actually gets reused.
A team from UCLA's Samueli School of Engineering and Ewha Womans University in South Korea has demonstrated a chemical approach, known as alkaline thermal treatment, that converts a mixture of polyethylene terephthalate, polyethylene, and polypropylene directly into hydrogen without requiring any prior sorting.
In the process, sodium hydroxide reacts with the plastics under heat, yielding hydrogen gas at purities exceeding 90 percent while simultaneously mineralizing the carbon dioxide that would otherwise be released, locking it into a solid form rather than emitting it into the atmosphere.
The reaction also runs at temperatures 300 to 400 degrees Celsius lower than conventional gasification, a reduction that could meaningfully lower the energy demands of scaling the technology up to an industrial level.
- constrain
- to limit or restrict something
- polymer
- a large molecule made of repeating chemical units, such as plastic
- labor intensive
- requiring a large amount of human work relative to output
- mineralize
- to convert a substance into a solid mineral form
- react
- to undergo a chemical change when combined with another substance
- emit
- to release or give off something, such as a gas
- gasification
- a process that converts organic material into gas through high heat
- industrial
- relating to large scale manufacturing or production
Level 4 — Advanced
Plastic recycling has long been constrained by the necessity of sorting mixed waste streams into discrete polymer categories prior to processing, a labor intensive step that inflates costs and curtails the proportion of plastic ultimately reclaimed.
A team from UCLA's Samueli School of Engineering and Ewha Womans University in South Korea has demonstrated a chemical approach, termed alkaline thermal treatment, that converts a mixture of polyethylene terephthalate, polyethylene, and polypropylene directly into hydrogen without any antecedent sorting.
In the reaction, sodium hydroxide interacts with the plastics under heat, yielding hydrogen gas at purities exceeding 90 percent while concurrently mineralizing the resultant carbon dioxide, sequestering it in solid form rather than emitting it into the atmosphere.
The reaction additionally proceeds at temperatures 300 to 400 degrees Celsius below those required for conventional gasification, a reduction that could substantially diminish the energy demands entailed in scaling the technology to an industrial level.
- discrete
- individually distinct and separate
- curtail
- to reduce in extent or quantity; to cut short
- antecedent
- coming before something in time or order
- concurrently
- happening at the same time as something else
- sequester
- to isolate or hide something away, often used for storing carbon
- resultant
- occurring or following as a result of something
- entail
- to involve something as a necessary consequence
- diminish
- to make or become smaller or less
Talk about this article with KatePractice this story's vocabulary in a real spoken conversation with your AI tutor