New catalyst could bring cleaner paper.
New catalyst means greener paper is not pulp fiction.
Pollution from paper production could be cut, say US chemists, with a new way of refining wood pulp1. But the process must go through the mill before it can convert industry.
During paper production, gluey wood component lignin is stripped out to leave stringy cellulose. The harsh chemicals used create environmental pollutants, such as toxic and long-lasting chlorinated compounds.
Paper manufacturing is one of the world’s largest industries. It generates 100 million tonnes of wood pulp a year. Using strong chemicals and high temperatures, pulping digests up to 90% of the lignin from wood chips. The resulting slurry is made into low-quality paper such as brown grocery bags.
For premium white paper, pulp is bleached and the remaining lignin is degraded using chlorine or the more environmentally friendly substitute, chlorine dioxide. These chemicals selectively break down lignin rather than cellulose by stealing its electrons, in an ’oxidation’ reaction. The new catalyst replaces this step.
The catalyst - called a polyoxometalate (POM) - was inspired by a protein in wood-digesting fungi. First, POM oxidizes lignin. Then oxygen re-oxidizes POM. This second step converts lignin to harmless carbon dioxide and water and recycles the catalyst.
At the end of the process, the catalyst must be carefully removed to avoid traces ending up in the paper. POM contains the heavy metals tungsten and molybdenum, also of concern to environmentalists.
Although this is "clever chemistry", says Terry Collins of Carnegie Mellon University in Pittsburgh, Pennsylvania, "it’s important that people keep experimenting with alternative technologies".
The inefficiency of the reaction means that 170 tonnes of catalyst are needed for every tonne of wood pulp, points out Collins, who works on green chemistry. This ratio would make working with the catalyst an expensive operation. He feels that new processes should aim to be cheap, efficient and non-toxic.
Weinstock argues that these criteria can be met and that the process can be made economically competitive.
HELEN PEARSON | © Nature News Service
Dispersal of Fish Eggs by Water Birds – Just a Myth?
19.02.2018 | Universität Basel
Removing fossil fuel subsidies will not reduce CO2 emissions as much as hoped
08.02.2018 | International Institute for Applied Systems Analysis (IIASA)
At the LASYS 2018, from June 5th to 7th, the Laser Zentrum Hannover e.V. (LZH) will be showcasing processes for the laser material processing of tomorrow in hall 4 at stand 4E75. With blown bomb shells the LZH will present first results of a research project on civil security.
At this year's LASYS, the LZH will exhibit light-based processes such as cutting, welding, ablation and structuring as well as additive manufacturing for...
There are videos on the internet that can make one marvel at technology. For example, a smartphone is casually bent around the arm or a thin-film display is rolled in all directions and with almost every diameter. From the user's point of view, this looks fantastic. From a professional point of view, however, the question arises: Is that already possible?
At Display Week 2018, scientists from the Fraunhofer Institute for Applied Polymer Research IAP will be demonstrating today’s technological possibilities and...
So-called quantum many-body scars allow quantum systems to stay out of equilibrium much longer, explaining experiment | Study published in Nature Physics
Recently, researchers from Harvard and MIT succeeded in trapping a record 53 atoms and individually controlling their quantum state, realizing what is called a...
The historic first detection of gravitational waves from colliding black holes far outside our galaxy opened a new window to understanding the universe. A...
A team led by Austrian experimental physicist Rainer Blatt has succeeded in characterizing the quantum entanglement of two spatially separated atoms by observing their light emission. This fundamental demonstration could lead to the development of highly sensitive optical gradiometers for the precise measurement of the gravitational field or the earth's magnetic field.
The age of quantum technology has long been heralded. Decades of research into the quantum world have led to the development of methods that make it possible...
02.05.2018 | Event News
13.04.2018 | Event News
12.04.2018 | Event News
23.05.2018 | Life Sciences
23.05.2018 | Physics and Astronomy
23.05.2018 | Materials Sciences