Chinese scientists use dirty waste from coal-fired power plants to make white paper

Scientists aim to improve the technology so that one day it can be used in every paper mill

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Chinese scientist recently made a breakthrough by using coal by-product as one of the key ingredients to make paper. More than 2,000 years after the invention of paper, the scientists of China are claiming that the result of this new process is almost indistinguishable from the paper used now, that is, the one made from wood pulp.

This comes almost 10 years after Professor Zhang Meiyun and her colleagues, from the Shaanxi University of Science and Technology first proposed that fly ash can be used as filler in paper. According to South China Morning Post, the result was more than 90 percent match to pure whiteness, though it was made with black fly ash which was produced from burning coal.

Reportedly, the breakthrough will also address two huge problems we are currently facing –the environmental impact due to the global demand for timber and also the problem of disposal of millions of tonnes of fly ash, each year. According to the World Wide Fund for Nature (WWF), paper mills use over 40 percent of the timber cut down globally for industrial use which "has devastating impacts on some of the world's most ecologically important places and species."

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"The first sheets that came out in our lab looked grey," Dr Song Shunxi from Shaanxi University of Science and Technology. "We had a Cinderella but the paper industry wanted a Snow White. It didn't work out very well." They figured that the reason was the presence of fly ash of unburnt carbon particles, reducing the brightness of the paper.

One of the largest state-owned electricity producers in the country, Datang Power, joined the program to give a solution to their problem. Reportedly, many coal beds in the country contain aluminium, and there's a chemical process to extract that aluminium from fly ash which is known to have a whitening effect.

As they predicted, the sheet turned bright but was too brittle and inflexible for use. The solution to the problem wasn't easy as the scientists found that improving one property of the material can lead to the degradation of another. "Plant fibre is organic, fly ash is not. Blending them together is difficult, and there are lots of gaps to fill between the fibres," Song said. "Nobody wants to use paper on which the ink spreads or which has dust coming off."

In 2014, the team finally found an effective formula addressing all elements in the papermaking process. The technology was perfect in the laboratory but factories didn't want to try it. "Thankfully we had the government behind us," Song said. "We will continue to improve the technology until one day it can be used in every paper mill," Song said.

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