Questão FC171271
Text 1A1-I Hydrogen is viewed as a promising alternative to fossil fuel, but the methods used to make it either generate too much carbon dioxide or are too expensive. Rice Universi
Interpretação de Textos (Understanding)
CEBRASPE (CESPE) · 2023
Hydrogen is viewed as a promising alternative to fossil fuel, but the methods used to make it either generate too much carbon dioxide or are too expensive. Rice University researchers have found a way to harvest hydrogen from plastic waste using a low-emission method that could more than pay for itself.
By comparison, “green” hydrogen ⎯ produced using renewable energy sources to split water into its two component elements ⎯ costs roughly US$ 5 for just over two pounds. Though cheaper, most of the nearly 100 million tons of hydrogen used globally in 2022 was derived from fossil fuels, its production generating roughly 12 tons of carbon dioxide per ton of hydrogen.
The researchers exposed plastic waste samples to rapid flash Joule, bringing their temperature up to 3100 Kelvin. “We demonstrated that we are able to recover up to 68% of that atomic hydrogen as gas with a 94% purity,” Kevin Wyss said. “I hope that this work will allow for the production of clean hydrogen from waste plastics, possibly solving major environmental problems like plastic pollution and the greenhouse gas-intensive production of hydrogen by steam-methane reforming.”
One of the drawbacks about the current forms of extraction of hydrogen as fuel is the elevated cost.
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Comentário: A afirmação está correta, pois o texto menciona que os métodos tradicionais de produção de hidrogênio, especialmente aqueles que utilizam fontes fósseis, geram grandes quantidades de dióxido de carbono e são considerados caros. O custo do hidrogênio "verde", que é produzido a partir de fontes renováveis, também é destacado como elevado, custando cerca de US$ 5 para uma quantidade específica. Assim, a precariedade dos métodos atuais, tanto em termos de custo quanto de impacto ambiental, é um dos principais obstáculos para a adoção em larga escala do hidrogênio como combustível. Portanto, a afirmação sobre o alto custo das formas atuais de extração de hidrogênio está correta.
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