CAREER: Holistic Assessment of the Potential of Byproduct-Derived Alkali-Activated Materials

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

This research targets to build an integrated framework to evaluate the environmental impact of using industrial byproducts as precursors in alkali-activated binders. Alkali-activated binders have been explored as a potential replacement for cement, which is a material with significant (and growing) contribution to global carbon dioxide emissions. The existence of significant amounts of industrial byproducts generated from energy production, mining and materials production, and solid waste management motivates development of strategies for economically-feasible beneficial use, so called industrial symbiosis. Repurposing these byproducts could not only reduce the impact associated with their disposal, but also potentially lower the environmental impact of construction materials if used as a cement replacement. However, knowing whether or not byproduct reuse is beneficial must be determined via detailed consideration of the context of the proposed symbiotic exchange. This research is designed to: a) develop a framework to assess environment, technical, and economic potential of beneficial use across broad range of industrial byproducts, 2) demonstrate the framework in an analysis of specific byproducts and 3) imbed key research findings in open data platforms as well as educational programs. By understanding the techno-environmental impacts of byproduct use in context, this project aims to provide quantitative tools to move towards a more circular economy, along a trajectory expected to be environmentally beneficial. The intellectual merit of this work derives from the integrated assessment of industrial symbiosis coupled with advanced material flow modeling and data mining methods. Analytical work will be performed to quantify the environmental impact of potential industrial byproduct reuse by combining existing and newly developed life cycle inventory (LCI) data with physical flow estimates. The approach will include integration of these environmental and resource use analyses with investigations to establish a processing-microstructure-property relationship for alkali-activated aluminosilicate binders. The physicochemical characteristics of the byproduct materials will be aggregated in a database along with physical flow and LCI information to establish a set of markers such as degree of crystallinity, solubility limits of aluminosilicate phase, carbon content and specific surface area. These characteristics influence aspects of an LCI such as the energy used to process precursors into final products, thereby influencing the resulting environmental impact. Exploring these technical relationships will be coupled with the systems analysis to evaluate the economic and environmental impact of proposed byproduct reuse strategies. To be relevant, the tools following from this research will provide results that: 1) are transferable to local context, 2) are on an open platform, and 3) measure performance relative to an appropriate incumbent technology. Incorporating environmental impact estimates into materials science will enable multi-objective design approaches, improving the selection criteria for those materials that are tested experimentally or in the field. As the work products and tools of the research mature, they will be directly integrated into open platforms to broaden the research impact so that the wider community can use, improve, and leverage ongoing data collection efforts to drive sustainable innovation. The PI aims to raise the awareness about the influence that the design and manufacture of materials have on our society. This will be done through 1) co-creation of sustainable materials curriculum with local teachers of 6-12th grade students, 2) incorporation into the PI's undergraduate and graduate courses at MIT and 3) online modules that can be disseminated broadly. This work will enable more capable environmental assessment tools, usable at earlier stages of the development process.