http://www.wiley-vch.de/vch/journals/2002/press/200812press.html

Press Release
Angewandte Chemie International Edition ,
doi: 10.1002/anie.200704510
Nr. 12/2008
Eco-Friendly Pyrotechnics
Fireworks pollute?nitrogen-rich compounds now pave the way for ecological
alternatives
Contact: Thomas M. Klapötke, Ludwig-Maximilians-Universität München
(Germany)
Registered journalists may download the original article here:
?Green? Pyrotechnics: A Chemists´ Challenge
You know it is chemistry when it stinks and goes boom?and entrances us.
?No other application in the field of chemistry has such a positive
association for the general population as fireworks,? says Thomas Klapötke
(University of Munich, Germany). ?However, pyrotechnical applications are
significant polluters of the environment.? In the journal Angewandte
Chemie, Klapötke and his co-author Georg Steinhauser (TU Vienna, Austria)
give an overview of how nitrogen-rich compounds and other new strategies
could help to limit the danger to the environment.
In addition to fireworks, the field of pyrotechnics includes applications
like airbags, signal flares, propellants and charges for civil and
military purposes, and the production of nanoporous metal foams for
catalysis, hydrogen storage, and insulation.
Pyrotechnical materials contain an oxidizer and a reducing agent;
depending on the application, binding material, propellant charges,
coloring agents and smoke- and sound-producing agents can be added. When a
firework or other pyrotechnic is set off, it releases a whole cocktail of
poisons damaging to humans and the environment: heavy metals like lead,
barium and chromium, chlorates, dioxins, smoke and particulates, carbon
monoxide, and nitrogen and sulfur oxides. ?For a long time, the
consequences of this were not considered,? says Klapötke, ?in the mean
time scientists have been working on more environmentally friendly
alternatives.? As usual, the main stumbling block is price pressure
because the new products must compete with the established ones. Klapötke
says, ?Lawmakers and other promoters must intercede to address this.?
?Modern developments in pyrotechnics are aimed at the use of nitrogen-rich
compounds,? according to Klapötke. In contrast to conventional energetic
substances, these do not draw their energy from the oxidation of the
carbon backbone, but from their high heats of formation, which are
released upon their decomposition. Interesting candidates include
derivatives of tetrazoles, five-membered rings made of four nitrogen and
one carbon atom, as well as tetrazines, six-membered rings made of four
nitrogen and two carbon atoms. Aminotetrazole salts with the nontoxic
metals lithium, sodium, potassium, rubidium and cesium result in red,
orange, violet, purple, and pink colored flames. The trouble is with the
color green. Intensive research is being carried out in search of
barium-free green-burning salts based on copper compounds.
The class of nitrogen-rich pyrotechnics does not offer only
environmentally friendly combustion products; they often offer better
color quality and intensity than conventional mixtures. Nitrogen-rich
propellants demonstrate improved performance and burn smoke free.
(2856 characters)

Best regards,
Au

Aurora Fe A. Ables
Project Coordinator and Knowledge Management Specialist (Consultant)
Urban Development Division, South Asia Department

Asian Development Bank
6 ADB Avenue, Mandaluyong City
1550 Metro Manila, Philippines
Tel +63 2 632 4444 local 70312     Fax +63 2 636 2293
aables[at]adb.org
www.adb.org

Promoting Best Practices in Private Sector Participation in Urban
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(ADB Regional TA 6300) for Asian Development Bank

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