Session: 12-03: Hydrogen Energy, Alternative Fuels, Bioenergy, and Biofuels

Paper Number: 138071

138071 - Decarbonizing High-Temperature Heat: An Analysis of Hydrogen Implementation in a Steel Furnace 

Abstract: 

The industrial sector is a significant contributor to US emissions, representing about 24% of the total emissions. Over half of these emissions result from the combustion of fossil fuels to generate process heat. The decarbonisation of high-temperature industrial processes (> 400 °C) is challenging, because direct electrification of high-temperature furnaces faces difficulties, especially when direct heating is necessary, and off-gases or flames come into direct contact with the product.

In the context of decarbonising high-temperature heat, green hydrogen emerges as a rapid and sustainable route. Industries with energy-intensive high-temperature processes, such as glass, ceramic, cement, and steel, can benefit from the use of green hydrogen. Challenges, on the other side, include the intermittent nature of renewable energy sources supplying the electrolysis process and formation of NOx due to high flame temperatures. While the NOx issue can be addressed with innovative hydrogen-fuelled burners, designing a power-to-hydrogen system to efficiently meet the thermal demand with the minimum cost remains crucial.

This study aims to investigate the decarbonisation of high-temperature heat in the steel sector. The chosen case study is a steel industry, particularly a high-temperature furnace located in an existing secondary steel (scrap-based) plant in Southern Europe. The plant is planning the replacement of the existing methane-fed burner with an innovative hydrogen-ready burner designed to reach up to 100% hydrogen as feedstock.

The system under investigation includes a burner capable of being supplied with either natural gas, hydrogen or a blend of the two gases. Natural gas is purchased from the grid, while hydrogen is locally produced using a low-temperature electrolyser powered by local renewable energy sources (such as PV and/or hydroelectric) and/or the electrical grid. To address the intermitted availability of renewable energy sources, the energy system includes both battery storage and hydrogen storage systems. A real hourly profile of the furnace thermal demand is integrated in the evaluation. The assessment employs a tool based on the Mixed-Integer Linear Programming (MILP) methodology, with the objective of identifying the cost-optimal solution (minimum net present cost) capable of meeting the thermal demand of the furnace. Various scenarios are explored, covering different H₂-CH₄ blending rates, as well as both single and hybrid renewable sources (PV/hydro), across a wide spectrum of energy prices. Additionally, the impact of a carbon tax on the energy system is analysed, providing a comprehensive assessment of the system's performance under diverse conditions.

Preliminary results show that, with the current carbon price in Europe (approximately 100 €/ton), hydrogen becomes economically viable compared to natural gas when the price of electricity is less than 0.5 times the price of natural gas. This value increases to 0.7-1.2 at a carbon price of 400 €/t. Notably, high shares of renewable electricity are found to play a pivotal role in enhancing the economic competitivity of green hydrogen and achieving competitive production costs.

Presenting Author: Marta Gandiglio Politecnico Di Torino

Presenting Author Biography: Dr. Marta Gandiglio, Assistant Professor, Department of Energy, Politecnico di Torino (Italy)
PhD in Energy Engineering from the Politecnico di Torino. She is a member of the research group STEPS (Synergies of Electrical Thermochemical and Electrochemical Systems, head prof. Massimo Santarelli). Her research activity is linked to the world of hydrogen and fuel cells (high and low temperature fuel cells, PEMFC, SOFC, MCFC, production and use of green hydrogen), as well as biofuels and in particular biogas (from agricultural, industrial and wastewater waste streams). She has worked on the modelling level (system modelling, techno-economic analyses, optimizations, and feasibility studies) and also at an experimental level (design, operation and data analysis of innovative industrial plants). She is responsible for the Energy and Renewable Energy Course and collaborator in the Polygeneration and Advanced Energy Systems Course. She is involved in several European projects including: DEMOSOFC, REMOTE, TULIPS, COMSOS and SOFCOM. She is a member of the European Biogas Association (EBA) and active in the Working Groups on Wastewater and Hydrogen. She is a project reviewer for the EU commission (Clean Hydrogen Initiative) and an External Expert for the International Energy Agency (IEA) and International Renewable Energy Agency (IRENA).

Authors:

Marta Gandiglio Politecnico Di Torino
Paolo Marocco Politecnico di Torino
Massimo Santarelli Politecnico di Torino