This NSF award funds U.S. researchers participating in a project competitively selected by the G8 Research Councils Initiative "Interdisciplinary Program on Material Efficiency - A first step towards sustainable manufacturing". This is a pilot collaboration among the U.S. National Science Foundation, the Canadian National Sciences and Engineering Research Council (NSERC), the French Agence Nationale de la Recherche (ANR), the German Deutsche Forschungsgemeinschaft (DFG), the Japan Society for the Promotion of Science (JSPS), the Russian Foundation for Basic Research (RFBR),and the United Kingdom Research Councils (RCUK), supporting collaborative research projects selected on a competitive basis that are comprised of researchers from at least three of the partner countries.
This award funds research supporting the design of a redesigned cement plant with improved material efficiency,including reduced carbon dioxide (CO2) emissions and enhanced waste disposal. These objectives will be met by redesigning the manufacturing process, enhancing the re-use and recycling of waste concrete, and producing longer lasting products by enhancing the mineral properties of clinker. The redesign will replace air with oxygen in the combustion process. The required flue gas recycling facilitates the capture of carbon dioxide as well as the expansion of alternative fuels, in particular sulfur, which reacts with limestone to produce gypsum, a component of cement. Increasing the CO2 partial pressure within the kiln changes process conditions sufficiently to alter the reaction sequence. Recycling will also be investigated as a unit process that carbonates lime leached from waste concrete using atmospheric carbon dioxide. The resulting limestone can be re-used as kiln feed or as filler in the paper industry. Improved mineral quality is derived from the shorter, hotter flame possible with oxygen combustion, resulting in longer product life. While additional energy will be required to produce the oxygen, the optimization will reduce thermal load and carbon dioxide emissions. Life Cycle Assessment (LCA) will be used to quantify material and energy flows, which can then be compared to existing cement manufacturing processes.
If successful, the novel cement manufacturing process will provide a net reduction in carbon dioxide emissions using an expanded alternative fuel portfolio that consumes its own waste, making a positive contribution to the upcoming challenges related to an aging infrastructure in OECD countries, and growing infrastructure in non-OECD countries. Sustainable development is critical as it is the only ethical means to reduce poverty, raise living standards and mitigate the impacts of development.
