Speaker
Description
Since 1990 Linde has converted 190 reheat furnaces to oxyfuel operations; 62 of them for heating of ingots before rolling or forging. Oxyfuel combustion can significantly increase energy efficiency and immediately reduce the carbon footprint, paving the way for the efficient future use of hydrogen as fuel. An overview of these installations and technology used, Flameless Oxyfuel, is presented.
The transition to green steelmaking is a multi-decade journey involving diverse technologies and pathways, in most scenarios with the use of hydrogen − both as reductant and as fuel − as the endgame. While its broader integration will take time, hydrogen as a fuel has already been proven to perform effectively in reheating operations, without compromising the preferred energy-efficient oxyfuel combustion or negative impact the steel product.
In early 2024, Ovako began the use of 100% hydrogen to fuel its existing Flameless Oxyfuel combustion systems in the soaking pit furnaces where steel is reheated before rolling at its plant at Hofors, Sweden. This was the successful conclusion of a five-year journey including laboratory scale tests and full-scale demonstrations in cooperation between Ovako and Linde. 48 furnaces, charged with about 25 tonnes of engineering or bearing steel grade ingots, are since then running permanently in this operation mode. The hydrogen is supplied by an onsite alkaline electrolyzer powered entirely by renewable electric power. The Flameless Oxyfuel combustion operates with 100% oxygen and 100% hydrogen. This technology, the challenges overcome, and the excellent results achieved are discussed along with the development of hydrogen-oxygen combustion.
At Ovako Hofors using 100% hydrogen as fuel at reheating is now a tangible and fully practical solution – to date successfully reheated more than 500,000 tonnes of ingots.
Operation with hydrogen in forge furnaces is the next step, also using Dual Momentum Lancing Flameless Oxyfuel burners.
| Speaker Company/University | Joachim von Scheele |
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