Session: 16-01: Poster Presentations

Paper Number: 138665

138665 - Graphite Thermal Storage for Industrial Heat Decarbonization 

Abstract: 

Achieving global net-zero greenhouse gas emissions necessitates the decarbonization of heavy industries such as steel, cement, and petrochemical manufacturing. These sectors predominantly rely on high-temperature heat, traditionally generated by burning fossil fuels. Challenges arise in directly electrifying these processes, especially in industries with low profit margins, where the fluctuating costs of electricity impede cost-effectiveness.

This study proposes the integration of thermal storage with renewable energy to economically decarbonize high-temperature industrial processes. It builds on previous research in grid-scale thermal energy storage for long-duration electricity storage, particularly a graphite-based sensible heat system using molten tin as a heat transfer fluid. This approach offers low capital costs and can handle heat up to 2400°C. Applied to industrial emissions, it has the potential to achieve cost parity with current practices without relying on a carbon tax while building on the knowledge that is continuing to be developed for grid storage.

Our research employs a technoeconomic model to optimize this thermal energy storage system for specific electricity grids. This enables identification of prime geographic locations for deployment and clarifies the technical requirements of the energy storage solution. Available parameters include the amount of storage, heater power, and location, which determines the relevant electricity market and availability of renewable energy generation. We conclude that grids with consistently low electricity prices for just a few hours a day, like those with substantial solar energy contribution, are ideal. In many places, the average price for these hours is near zero or negative, offering abundant energy if it can be captured and stored. When coupled with fast-charging thermal storage, such systems can capitalize on sporadic price drops, achieving a levelized cost of heat (LCOH) comparable to natural gas. Other thermal energy storage technologies struggle to reach this key threshold in part due to their high capital costs. These costs are driven down with this technology by the use of materials with exceptionally high maximum temperature, as well as the use of a liquid heat transfer fluid.

However, technological and economic challenges persist. Technologically, issues remain with the heat exchanger design between the molten tin and the industrial working fluid and the transport of fluid within the oxidation-sensitive storage system. Economically, the implementation hinges on access to real-time electricity market pricing, which many industrial customers lack. This research outlines a path forward for the decarbonization of high-temperature industrial processes, addressing both the potential and the hurdles of this innovative approach. We identify glass manufacturing as a suitable starting point for implementation because a large majority of the greenhouse gas emissions resulting from this process are from heating.

Presenting Author: Kyle Buznitsky MIT

Presenting Author Biography: Kyle Buznitsky is a Ph.D. candidate in the Department of Mechanical Engineering at the Massachusetts Institute of Technology with a focus on thermal fluids. His research focuses on high-temperature thermal energy storage and decarbonization. He received his Bachelor of Science in mechanical engineering from Rutgers University-New Brunswick with a concentration in energy systems and an economics minor.

Authors:

Kyle Buznitsky MIT
Luis Velasquez-Mansilla Massachusetts Institute of Technology
Asegun Henry Massachusetts Institute of Technology