Given the growing world population and urban density, management of municipal solid waste is becoming an increasingly difficult issue. One way to approach handling of all this solid waste is to incinerate it for energy as is done in Waste-to-Energy plants. However, the residual ash (bottom and fly ash) post combustion of this waste is unused and often sent to the landfill. There is potential in utilizing this ash for several commercial applications if its chemical composition and mineralogy could be understood in detail.
Garg Group has recently received funding from Advanced Research Projects Agency – Energy (ARPA-E) for a two year project (2021-2023) for investigating the chemistry of these ashes and then identifying composition dependent end uses. The project is titled RADAR-X (Rapid AI-based Dissection of Ashes using Raman and XRF Spectroscopy). This is an interdisciplinary project in collaboration with Prof. Jeffery Roesler, Dr. Brajendra K. Sharma, and Prof. Lav Varshney. This project will build upon the findings from an earlier project on municipal solid waste which was seed funded by the Institute for Sustainability, Energy, and Environment at University of Illinois, Urbana-Champaign. Some more information on this new project can be found here.
We are excited to continue our efforts in this field to make our world a sustainable world!
A new publication titled “Enabling Phase Quantification of Anhydrous Cements via Raman Imaging” was published in Cement and Concrete Research in September 2021.
Quantifying the mineral phase composition of an anhydrous cement is essential in determine/predicting the hydrated phase assemblage which consequently governs the overall performance of hardened concrete. Traditional techniques such as X-ray diffraction, optical microscopy, and electron microscopy are well suited to quantify phases in anhydrous cements but they may have some sample-specific limitations in certain scenarios. Here, we demonstrate Raman imaging as a complementary tool for quantitative phase analysis on 11 different cements. Using sufficient statistics (250,000 spectra per image, 5×5 mm area scans with 10 μm/pixel in each image), we were able to accurately quantify the 4 principal phases (alite, belite, aluminate, and ferrite) as well as (up to) 8 secondary phases (gypsum, anhydrite, bassanite, syngenite, dolomite, calcite, quartz, and portlandite) in a broad variety of cements. These results pave the way for future application of Raman imaging for phase quantification in other complex mixtures and systems.
This is the second article from our group’s Ph.D. candidate Krishna C. Polavaram. Congratulations Krishna!