041

Title:

Use of High Ettringite Producing Cement Systems for Use in Thermochemical Energy Storage

Discipline: Civil Engineering

Presenter:

Aaron Strand

Abstract:

Long-term energy storage through reversible thermochemical processes are increasingly being examined for the next wave of energy efficient power grids. Ettringite provides a possible medium for thermochemical storage through the ettringite-metaettringite conversion process. While rare in nature, ettringite is commonly found cementitious systems. When used energy storage medium the hysteresis of the dehydration and rehydration of the ettringite crystal from ettringite into metaettringite is paramount. If the ettringite decomposes to a form other than metaettringite such as monosulfate; the hysteresis loop between ettringite and metaettringite will cease to continue with the input energy nonrecoverable. Current research has focused of high ettringite producing cements such as calcium sulfoaluminate cement (CSA) due to their high ettringite content upon hydration, however these systems can be quite expensive compared to systems that are predominantly made with portland cement. The objective of this research was to examine cement blends with a composition of portland cement, calcium aluminate cement (CAC), and calcium sulfate (C$) for possible use as a high ettringite producing cement system for use in thermochemical storage. Analysis done to measure the stability of hysteretic dehydration and rehydration cycle through repetitive environmental conditioning and mass measurement and energy output through the use of the isothermal calorimetry. The impact of environmental conditions, and blend ratios of portland cement to CAC+C$ were determined and compared to pure CSA systems. These results obtained from this research are presented.

Author(s):

Aaron Strand, Dr. Matthew Adams

Funding Acknowledgements:

NJIT Faculty Seed Grant