Nanotechnology Now





Heifer International

Wikipedia Affiliate Button


DHgate

Home > Press > Up in Flames: Evidence Confirms Combustion Theory: Berkeley Lab and University of Hawaii research outlines the story of soot, with implications for cleaner-burning fuels

Graphical representation of the chemistry in the early stages of soot formation. The mechanism to the right was demonstrated by experiment, while the one on the left was not. Credit: Dorian Parker, University of Hawaii
Graphical representation of the chemistry in the early stages of soot formation. The mechanism to the right was demonstrated by experiment, while the one on the left was not.

Credit: Dorian Parker, University of Hawaii

Abstract:
Researchers at the Department of Energy's Lawrence Berkeley National Lab (Berkeley Lab) and the University of Hawaii have uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and other carbon-based compounds.

Up in Flames: Evidence Confirms Combustion Theory: Berkeley Lab and University of Hawaii research outlines the story of soot, with implications for cleaner-burning fuels

Berkeley, CA | Posted on July 1st, 2014

The finding could help combustion chemists make more-efficient, less-polluting fuels and help materials scientists fine-tune their carbon nanotubes and graphene sheets for faster, smaller electronics. In addition, the results could have implications for the burgeoning field of astrochemistry, potentially establishing the chemical process for how gaseous outflows from stars turn into carbon-based matter in space.

"When you burn a flame, you start with a gas-phase reactant and then analyze the products, which include soot," says Musahid Ahmed, scientist in the Chemical Sciences Division at Berkeley Lab. "But there is no direct evidence for the chemical bonds that break and form in the process." For more than 30 years, scientists have developed computational models of combustion to explain how gas molecules form soot, but now Ahmed and his colleagues have data to confirm one long-standing theory in particular. "Our paper presents the first direct observation of this process," he says.

While the research is relevant to a number of disciplines—combustion science, materials science, and astrochemistry—it's combustion science that could see the most direct impact the soonest, says Ahmed. Specifically, the fundamental chemistry discovery could be used to find or design fuels that burn cleaner and don't produce as much soot.

Think about your car engine. If the combustion process were perfect, only carbon dioxide and water would come out of the tailpipe. Instead, we see fumes and particulates like soot, a visible macromolecule made up of sheets of carbon.

Theoretically, there are hundreds of different ways molecules can combine to create these dirty emissions. But there has been one popular class of mechanisms that outlines possible early steps for bond making and bond breaking during combustion. Called hydrogen abstraction-acetylene addition, or HACA, it was developed by Michael Frenklach professor of mechanical engineering at the University of California Berkeley in 1991.

One version of HACA works like this: during the high-temperature, high-pressure environment of combustion, a simple ring of six carbon and six hydrogen atoms, called benzene, would lose one of its hydrogen atoms, allowing another two-carbon molecule called acetylene, to attach to the ring, giving it a kind of tail. Then the acetylene tail would lose one of its hydrogen atoms so another acetylene could link up in, doubling the carbon atoms in the tail to four.

Next, the tail would curl around and attach to the original ring, creating a double-ring structure called naphthalene. Link by link, ring by ring, these molecules would continue to grow in an unwieldy, crumpled way until they became the macromolecules that we recognize as soot.

To test the first step of the theoretical HACA mechanism, Ahmed and collaborators from the University of Hawaii used a beamline at the Advanced Light Source (ALS) at Berkeley Lab specifically outfitted to study chemical dynamics. The ALS, a DOE Office of Science user facility, produces numerous photons over a wide range of energies, allowing researchers to probe a variety of molecules produced in this chemical reaction with specialized mass spectrometry analysis.

Unique to this experimental setup, Ahmed's team used a so-called hot nozzle, which recreates combustion environment in terms of pressure and temperature. The group started with a gaseous mix of nitrosobenzene (a benzene ring with a molecule of nitrogen and oxygen attached) and acetylene, and pumped it through a heated tube at a pressure of about 300 torr and a temperature of about 750 degrees Celsius. The molecules that came out the other end were immediately skimmed into a mass spectrometer that made use of the synchrotron light for analysis.

The researchers found two molecules predominantly emerged from the process. The more abundant kind was the carbon ring with a short acetylene tail on it, called phenylacetylene. But they also saw evidence for the double ring, naphthalene. These results, says Ahmed, effectively rule out one HACA mechanism—that a carbon ring would gain two separate tails and those tails would bond to form the double ring—and confirm the most popular HACA mechanism where a long tail curls around to form naphthalene.

Ahmed's local team included Tyler Troy, postdoctoral fellow at Berkeley Lab, and this work was performed with long-term collaborator Ralf Kaiser, professor of physical chemistry at the University of Hawaii at Manoa, and Dorian Parker, postdoctoral fellow also at Hawaii. The research was published June 20 online in the journal Angewandte Chemie.

"Having established the route to naphthalene, the simplest polycyclic aromatic hydrocarbon, the next step will be to unravel the pathways to more complex systems," says Kaiser.

Further experiments will investigate these follow-up mechanisms. It's a tricky feat, explains Ahmed, because the molecular possibilities quickly multiply. The researchers will add infrared spectroscopy to their analysis in order to catch the variety of molecules that form during these next phases of combustion.

This research was funded by the DOE Office of Science.

####

About DOE/Lawrence Berkeley National Laboratory
Lawrence Berkeley National Laboratory addresses the world’s most urgent scientific challenges by advancing sustainable energy, protecting human health, creating new materials, and revealing the origin and fate of the universe. Founded in 1931, Berkeley Lab’s scientific expertise has been recognized with 13 Nobel prizes. The University of California manages Berkeley Lab for the U.S. Department of Energy’s Office of Science. For more, visit www.lbl.gov.

The DOE Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, please visit science.energy.gov.

For more information, please click here

Contacts:
Kate Greene

510-486-4404

Copyright © DOE/Lawrence Berkeley National Laboratory

If you have a comment, please Contact us.

Issuers of news releases, not 7th Wave, Inc. or Nanotechnology Now, are solely responsible for the accuracy of the content.

Bookmark:
Delicious Digg Newsvine Google Yahoo Reddit Magnoliacom Furl Facebook

Related Links

The chemical dynamics beamline can be viewed on the web at:

Snapshots of Ahmed’s science are available at:

Prof. Kaiser’s homepage is here:

Related News Press

Laboratories

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015

News and information

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015

Chemistry

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Graphene

Haydale Named Lead Sponsor for Cambridge Graphene Festival May 22nd, 2015

Record high sensitive Graphene Hall sensors May 21st, 2015

Simulations predict flat liquid May 21st, 2015

INSIDDE: Uncovering the real history of art using a graphene scanner May 21st, 2015

Govt.-Legislation/Regulation/Funding/Policy

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015

Turn that defect upside down: Twin boundaries in lithium-ion batteries May 21st, 2015

Nanotubes/Buckyballs/Fullerenes

Basel physicists develop efficient method of signal transmission from nanocomponents May 23rd, 2015

Researchers develop new way to manufacture nanofibers May 21st, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Cotton fibres instead of carbon nanotubes May 9th, 2015

Discoveries

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Announcements

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Interviews/Book Reviews/Essays/Reports/Podcasts/Journals/White papers

Engineering Phase Changes in Nanoparticle Arrays: Scientists alter attractive and repulsive forces between DNA-linked particles to make dynamic, phase-shifting forms of nanomaterials May 25th, 2015

Nanostructures Increase Corrosion Resistance in Metallic Body Implants May 24th, 2015

Iranian Scientists Use Magnetic Field to Transfer Anticancer Drug to Tumor Tissue May 24th, 2015

This Slinky lookalike 'hyperlens' helps us see tiny objects: The photonics advancement could improve early cancer detection, nanoelectronics manufacturing and scientists' ability to observe single molecules May 23rd, 2015

Environment

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

Directa Plus in Barcelona to present the innovative project GEnIuS for oil spills clean-up activities: The company has created a graphene-based product for the remediation of water contaminated by oil and hydrocarbons May 21st, 2015

Nano-policing pollution May 13th, 2015

Chemists strike nano-gold: 4 new atomic structures for gold nanoparticle clusters: Research builds upon work by Nobel Prize-winning team from Stanford University April 28th, 2015

Energy

Visualizing How Radiation Bombardment Boosts Superconductivity: Atomic-level flyovers show how impact sites of high-energy ions pin potentially disruptive vortices to keep high-current superconductivity flowing May 23rd, 2015

Conversion of Greenhouse Gases to Syngas in Presence of Nanocatalysts in Iran May 22nd, 2015

Sandia researchers first to measure thermoelectric behavior by 'Tinkertoy' materials May 20th, 2015

Industrial Nanotech, Inc. Announces Official Launch of the Eagle Platinum Tile™ May 19th, 2015

Automotive/Transportation

Wearables may get boost from boron-infused graphene: Rice U. researchers flex muscle of laser-written microsupercapacitors May 18th, 2015

ORNL demonstrates first large-scale graphene fabrication May 14th, 2015

Penn and UC Merced researchers match physical and virtual atomic friction experiments May 8th, 2015

Silicon Storage Technology and GLOBALFOUNDRIES Announce Qualification of Automotive Grade 55nm Embedded Flash Memory Technology May 5th, 2015

Aerospace/Space

ORNL demonstrates first large-scale graphene fabrication May 14th, 2015

International and U.S. Students and Teachers Headed to Toronto for 34th Annual International Space Development Conference®: Students competed in prestigious NSS-NASA Ames Space Settlement Design Contest May 9th, 2015

'Microcombing' creates stronger, more conductive carbon nanotube films May 5th, 2015

Iranian Scientists Present Model to Study Mechanical Vibrations of Structures Containing Nanocomposites May 5th, 2015

Research partnerships

Supercomputer unlocks secrets of plant cells to pave the way for more resilient crops: IBM partners with University of Melbourne and UQ May 21st, 2015

Taking control of light emission: Researchers find a way of tuning light waves by pairing 2 exotic 2-D materials May 20th, 2015

Efficiency record for black silicon solar cells jumps to 22.1 percent: Aalto University's researchers improved their previous record by over 3 absolute percents in cooperation with Universitat Politècnica de Catalunya May 18th, 2015

Organic nanoparticles, more lethal to tumors: Carbon-based nanoparticles could be used to sensitize cancerous tumors to proton radiotherapy and induce more focused destruction of cancer cells, a new study shows May 18th, 2015

NanoNews-Digest
The latest news from around the world, FREE




  Premium Products
NanoNews-Custom
Only the news you want to read!
 Learn More
NanoTech-Transfer
University Technology Transfer & Patents
 Learn More
NanoStrategies
Full-service, expert consulting
 Learn More










ASP
Nanotechnology Now Featured Books




NNN

The Hunger Project