Aluminum scrap found a new use when scientists at the University of York used sea water and scrap metal to develop a technology to help capture more than 850 million tons of unwanted carbon dioxide in the atmosphere and safely trap the gas as dawsonite, according to an article on the University of York web site.
Professor Michael North, from the University’s Department of Chemistry, said: “We started with the realization that using graphite, the material used in pencils, to line aluminum reactors, results in the mineralization of carbon dioxide. We wanted to trap the gas at much higher levels, using low-energy processes, so we decided to look at waste materials, such as scrap metals, to see if this could be done without using chemical agents as a catalyst.”
Researchers filled the aluminum reactor with sea water and waste aluminum foil. The gas was transferred to the sea water inside the reactor. Electricity, captured from solar panels, was passed through it, resulting in the aluminum turning the dissolved carbon dioxide into the mineral dawsonite.
The process works without high energy gas-pressurization, toxic chemicals, and hydrogen. Instead, hydrogen is produced from the electrical circuit and becomes a side-product of the process. Researchers are now working to maximize the energy efficiency of the process and allow the hydrogen by-product to be collected and utilized, before seeking to build toward full-scale production.
This work is published in the journal ChemSusChem.
Aluminum contributes to green technology in other ways. For starters, it is 100% recyclable and can be recycled indefinitely. According to the Aluminum Association web site, nearly 75% of all aluminum ever produced is still in use, and recycling aluminum saves more than 90% of the energy needed to make new aluminum. Aluminum is a key component in LEED-certified green buildings because properly coated aluminum roofs can reflect up to 95% of the solar energy that strikes them, dramatically improving energy efficiency.
Aluminum has green applications in the automotive industry as well, where it is emerging as a lightweight, more energy-efficient alternative to steel for certain components. To comply with the National Highway Traffic Safety Administration’s Corporate Average Fuel Economy (CAFE) standards and other regulations, automotive manufacturers are frequently using aluminum for body panels instead of steel to reduce the weight of the vehicle, which will help increase the fuel economy. The Aluminum Association website explains that when applied to an optimized automotive body structure, aluminum can provide a weight savings of up to 50% compared with the traditional mild steel structure. And aluminum body structures are equal or superior in strength to steel and absorb twice as much crash-induced energy.
To reduce the weight of components even further, aluminum is alloyed with other elements. Making sure the alloys used in automotive manufacturing have the correct chemical composition is critical to the structural integrity of the vehicle. Manufacturers rely on XRF technology and XRF analyzers for the elemental analysis of specialty alloys to ensure the correct alloys are combined in the right percentages and the finished material meets precise manufacturing specifications.