Tailoring Cementitious Materials Towards Value-Added Use of Large CO2 Volumes
Small Business Information
1926 Turner Street, Lansing, MI, 48864-4051
AbstractCarbon capture and storage is generally considered as a crucial component of any U.S. strategy for addressing the climate change problem. Carbon dioxide can be stored underground in geologic formations, or permanently bound into some abundant minerals via carbonation reactions. These options have been subject of significant research and development efforts. The proposed project employs the advances made in mineral carbonation in order to advance another important option for carbon capture where carbonation reactions are used to add value to cementitious materials which are used in massive quantities. Significant advances made in CO2 sequestration via mineral carbonation provide valuable lessons that could be used to refine the chemistry of cementitious materials for magnifying the rate, extent and benefits of carbonation reactions in concrete. The proposed project will adapt these lessons towards modifying the composition of cementitious materials for enhancing the beneficial use of carbonation reactions in concrete. The project will consider conventional Portland cement and also the more sustainable cementitious materials that are receiving growing commercial attention for lowering the carbon footprint and energy content of concrete. Beneficial use of carbonation in cementitious materials requires complementary use of hydration and carbonation reactions to improve the productivity, density, binding attributes, stability, barrier qualities and durability of cementitious materials. An integrated theoretical/experimental investigation will be conducted in Phase I effort to validate the potential for enhancing beneficial carbonation reactions via chemical modification of cementitious materials. The options to be evaluated for chemical modification of cementitious materials include: (i) addition of sodium bicarbonate to form a buffer solution which accelerates the dissolution and precipitation steps in carbonation, and acts as an effective CO2 carrier; (ii) addition of free CaO and MgO which, due to their reactivity with carbonic acid, enhance the carbonation reactivity of solutes, and raise the carbonation potential of cementitious materials; (iii) addition of alkalis to accelerate carbonation reactions, and to restore the pore solution alkalinity; and (iv) addition of (ground) abundant minerals based on magnesium oxide silicates, which can undergo direct carbonation reactions to benefit concrete products subjected to accelerated thermal curing. The proposed project will also evaluate mechanosorption as a practical and versatile approach to delivery of carbon dioxide, which promises to facilitate broader adoption of the technology by the concrete industry. Life-cycle analyses will be performed in order to assess the benefits of the technology in terms of CO2 sequestration, and energy and cost savings. Commercial Applications and Other Benefits: The technology promises to: (i) permanently bind substantial quantities of CO2; (ii) raise the productivity of concrete construction; (iii) enhance the engineering properties, service life, and initial and life-cycle economy of the concrete-based infrastructure; and (iv) reduce the energy content of concrete products. These advantages of the technology would benefit the public and the concrete industry by contributing towards CO2 sequestration, energy saving, and improvement of the economics and reliability of the concrete-based infrastructure.
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