ISTC scientists are developing new and value-added uses for fly ash, a powdery remnant of burning coal.
Coal ash consists of four main components: fly ash, bottom ash, boiler slag, and flue gas desulfurization material. The traditional disposal method for this material includes holding wet coal ash in dewatering ponds and then disposing of both dewatered and dry coal ash in landfills. However, these wastes contain high concentrations of heavy metals such as mercury, cadmium, and arsenic. This has created major concerns about water and air contamination from these wastes.
While renewable energy generation is ideal for reducing energy generation byproducts like fly ash, scaling up these technologies to meet energy demand is still a long way off. The need for safe, alternative disposal methods for coal ash, such as beneficial reuse, is urgent.
To help solve this problem, ISTC scientists will use their expertise in modifying vegetable oils to encapsulate the coal fly ash so that the contaminants are fully contained. This will not only reduce the amount of fly ash waste and lessen the risk of heavy metals leaching into surface and groundwater but also increase the market for fly ash in products other than concrete and construction materials. Encapsulating the fly ash in vegetable oil will reduce heavy metal exposure because the smallest fly ash particles contain the highest concentrations of toxic compounds. The encapsulated fly ash could then be used as fillers and toughening agents in plastics. If the project is successful, it will also make transporting fly ash long distance more economically feasible, provide incentives to size and store fly ash, and create non-seasonal product demand.
The U.S. Department of Energy funded this $1 million, two-year project.
Additional Reading
DOE-funded project to find beneficial uses for coal combustion wastes