Scientists are creating fireworks made of chemicals that don't pollute the atmosphere. These environmentally friendly fireworks could also offer better color quality and intensity than conventional fireworks.
Smoke after fireworks. Credit: Rolf Broberg Chemists Thomas Klapötke from the University of Munich in Germany and Georg Steinhauser from TU Vienna in Austria have investigated making fireworks out of nitrogen-rich compounds. Such fireworks would burn smoke-free, eliminating the massive black clouds that form on Fourth of July evenings.
When a conventional firework is set off, many pollutants fill the air, such as lead, barium, chromium, chlorates, dioxins, smoke and particulates, carbon monoxide, and nitrogen and sulfur oxides.
"For a long time, the consequences of this were not considered," Klapötke said. "In the meantime, scientists have been working on more environmentally friendly alternatives."
Conventional fireworks draw their energy from the oxidation of carbon. Clean fireworks, on the other hand, would get energy from the high temperatures that occur with the formation of nitrogen-rich compounds. Some possible compounds could be tetrazoles and tetrazines, which are made of four nitrogen atoms and either one or two carbon atoms, respectively.
To produce different colors, chemists could use aminotetrazole salts with specific non-toxic metals. For example, lithium, sodium, potassium, rubidium and cesium result in red, orange, violet, purple, and pink flames, respectively.
Somewhat ironically, the most difficult color to produce with "green" fireworks is green. The researchers are looking into green-burning salts based on copper compounds.
But the biggest challenge will likely be selling the fireworks at a competitive price. Klapötke things that, in order for clean fireworks to become a practical alternative, lawmakers must step in at first to make the fireworks more economical.
via: Innovations Report