Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Clean sheet for paper making

08.11.2001


New catalyst could bring cleaner paper.
© Corbis


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.



A new chemical catalyst makes harmless gas oxygen do the same job, Craig Hill of Emory University in Atlanta, Georgia and his colleagues have shown. "It’s set up for being green chemistry," says joint team leader Ira Weinstock of the US Department of Agriculture Forest Service in Madison, Wisconsin.

"It’s a noble effort," says industrial chemist William Kruper of the Dow Chemical Company in Midland, Michigan. But unless the catalyst’s efficiency is improved, "the industry isn’t going to adopt this technology tomorrow", he warns.

Waste paper

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.

References

  1. Weinstock, I. A. et al. Equilibriating metal-oxide cluster ensembles for oxidation reactions using oxygen in water. Nature, 414, 191 - 195, (2001).


HELEN PEARSON | © Nature News Service
Further information:
http://www.nature.com/nsu/011108/011108-9.html

More articles from Ecology, The Environment and Conservation:

nachricht Successful calculation of human and natural influence on cloud formation
04.11.2016 | Goethe-Universität Frankfurt am Main

nachricht Invasive Insects Cost the World Billions Per Year
04.10.2016 | University of Adelaide

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Significantly more productivity in USP lasers

In recent years, lasers with ultrashort pulses (USP) down to the femtosecond range have become established on an industrial scale. They could advance some applications with the much-lauded “cold ablation” – if that meant they would then achieve more throughput. A new generation of process engineering that will address this issue in particular will be discussed at the “4th UKP Workshop – Ultrafast Laser Technology” in April 2017.

Even back in the 1990s, scientists were comparing materials processing with nanosecond, picosecond and femtosesecond pulses. The result was surprising:...

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Closing the carbon loop

08.12.2016 | Life Sciences

Applicability of dynamic facilitation theory to binary hard disk systems

08.12.2016 | Physics and Astronomy

Scientists track chemical and structural evolution of catalytic nanoparticles in 3-D

08.12.2016 | Materials Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>