Chemicals from waste plastic could be used in detergent, paint or medicine.

废塑料中的化学物质可以用于洗涤剂、油漆或药品。

By Charles Q. Choi | INSIDE SCIENCE

《科学内幕》记者查尔斯·Q·崔报道



在接下来的12个月里,一项旨在消除海洋塑料垃圾的工作将会开展。



海洋清理基金会(Ocean Cleanup Foundation)开发了一种新的漂浮锚设计(用以清楚海洋垃圾)。



这种漂浮锚设计的被动系统将随着洋流移动到塑料垃圾含量最高的海域。



然后塑料将被收集到屏障内,接着带回陆地进行回收。

New system design allows for cleanup of ocean plastic 2 years ahead of schedule

这个新的系统将使海洋塑料垃圾的清理工作提前两年完成。

The Ocean Cleanup's new system includes a floating anchor, allowing it to move to the locations with the highest concentrations of plastic.

这个新的海洋清理系统设计了一个漂浮的锚,这个漂浮的锚可以移动到塑料浓度最高的地方。

This is an Inside Science story.

《科学内幕》将带你揭秘这个新科技。

A novel technique can simultaneously break down the most commonly used form of plastic and synthesize valuable, widely used molecules, potentially making some plastic waste recycling more attractive and practical, a new study finds.

一项新的研究发现,一种新技术可以将最常用的塑料分解的同时,还可以合成有价值的、可广泛应用的分子,这项技术可能使一些塑料垃圾的回收更具吸引力和实用性。

Roughly 300 million metric tons of plastic waste is created every year, with nearly 12 billion metric tons of such garbage expected to pollute the planet by 2050. The molecule polyethylene, often used in packaging and grocery bags, is the largest component of plastic waste, and may take many centuries to decompose, said study senior author Susannah Scott, a chemical engineer at the University of California, Santa Barbara.

每年人类活动大约产生3亿吨塑料垃圾,根据这个速度,预计到2050年将有近120亿吨塑料垃圾,这会对地球造成严重的污染。加州大学圣巴巴拉分校的化学工程师苏珊娜·斯科特是该研究的资深作者,她表示,通常用于包装和购物袋的聚乙烯分子是塑料垃圾中主要的组成部分,这种化学物质可能需要几个世纪才能自然分解。

One problem with plastic is that it is cheaper and easier to produce and throw away than it is to recycle. Products made from recycled plastics often possess inferior properties to newly made ones, and breaking plastics down to their original building blocks is often complex and requires a lot of energy or chemicals, so the resulting products often don't recoup those costs.

塑料垃圾问题之所以越演越烈,主要是因为回收不划算。与回收相比,直接生产和丢弃塑料制品更加方便和便宜。回收塑料制成的产品通常比新制造的产品性能差,而且将塑料分解成小颗粒塑料通常需要大量的能源或化学物质,工艺很复杂,所以,回收塑料制成产品的成本往往比最终产品的的价值还高。

They are able to turn a low-value product into a high-value product.

科学家们(的新技术)能够把低价值的产品变成高价值的产品。

One potential way to address this economic hurdle is to "upcycle" plastic waste -- to convert it into valuable chemicals. However, this often involves the energy-intensive, laborious step of breaking the plastic down to its basic components before synthesizing the desired compounds.

解决(回收成本过高)这一经济障碍的一个潜在方法是对塑料垃圾进行“升级循环”,换句话说,就是将塑料垃圾转化为更有价值的化学物质。要将塑料垃圾合成所需的化合物,往往得涉及到将塑料垃圾分解为基本成分的过程,但是这一步骤既耗能又耗力。

Now Scott and her colleagues have developed a simple, low-energy technique for converting polyethylene into alkylaromatic compounds, which are the basis of many detergents, lubricants, paints, solvents, pharmaceuticals and other industrial and consumer products and currently support a $9 billion market annually. They successfully tested their method on actual polyethylene waste consisting of a plastic bag and a water bottle cap.

最近,斯科特和她的同事开发了一种简单而又低能耗的技术,该技术可以将聚乙烯转化为烷基化合物。而烷基化合物是许多洗涤剂、润滑剂、油漆、溶剂、药品和其他工业和消费产品的基础成分,该化学物质目前每年有着90亿美元的市场。这个科研团队在由塑料袋和水瓶盖组成的实际聚乙烯废料上测试了他们的方法并取得了成功。


"Polyethylene is one of the most used and produced plastics in the world -- there is an enormous waste stream available," said Bert Weckhuysen, a chemical engineer at Utrecht University in the Netherlands, who did not participate in this study but wrote a perspective article on the research for the journal. "They are able to turn a low-value product into a high-value product."

荷兰乌得勒支大学的化学工程师伯特·韦克休森说: “聚乙烯是世界上使用和生产最多的塑料之一,所以有大量的废物可以利用。” 伯特虽然没有参与这项研究,但他为本杂志写了一篇关于这项研究的看法文章。他说,“这个技术能够把低价值的产品变成高价值的产品。”

Only moderate temperatures are required, whereas conventional methods for manufacturing alkylaromatics typically demand temperatures of 500 to 1,000 degrees C (about 930 to 1,830 degrees F), this new process just needs about 300 degrees C (roughly 570 degrees F). It also does not call for water or any other solvent -- it simply requires cooking polyethylene with a common kind of catalyst made of platinum nanoparticles on alumina grains, long used in oil refining.

传统的制造烷基化学的方法通常需要500到1000摄氏度(约930到1830华氏度)的温度,而这项新技术只需要中等的温度就可以工作,整个过程只需要大约300摄氏度(大约570华氏度)就足够了。这个过程也不需要水或任何其他溶剂,只需要用一种常见的催化剂来烹饪聚乙烯。(这种催化剂由氧化铝颗粒上的铂纳米颗粒制成,长期用于炼油。)



"In this sense, using plastic is not second-best but actually preferred, and it gives a new way to look at the value of plastic waste," Scott said. "We are reminded that plastics are highly engineered and processed materials whose energy and chemical content represents an opportunity rather than a disadvantage to overcome."

“从这个意义上说,利用塑料并不是一个无奈之选,而是真正的首选,这会让塑料垃圾的价值变得更高,而人们看待塑料垃圾的方式也会发生改变。” 斯科特继续说道, “这一发现让我们意识到塑料是经过高度加工的材料,其能量和化学成分代表着机遇,塑料垃圾不再是需要克服的麻烦。”


Although the catalyst is itself expensive, "its cost is amortized over the enormous amount of product it can generate over many years," Scott said. Weckhuysen noted future research can explore developing cheaper alternatives.

斯科特还说,尽管催化剂本身很昂贵,“但它的成本要分摊到多年后它能生产的大量产品上。” 韦克休森也指出,未来的研究可以寻找更廉价的替代品来取代催化剂。

Future research could not only explore ways to make this catalyst more effective, but also investigate different catalysts that can break down other plastics or generate other valuable products, Scott said. This could help pave the way toward a future where plastic is not considered waste but rather a valuable raw material, Weckhuysen said.

斯科特说,未来的研究不仅可以探索使这种催化剂更有效的方法,还可以研发可以分解其他塑料或产生其他有价值的产品的不同催化剂。韦克休森说,这将改变人们将塑料视为垃圾的看法,也会为将塑料垃圾转变为一种有价值的原材料铺平道路。

The scientists detailed their findings in the Oct. 23 issue of the journal Science.

科学家们在10月23日出版的《科学》杂志上详细介绍了他们的发现。