Opinion – Rodrigo Tavares: Can green steel define the 21st century?

Steel is the skeleton that supports modern societies. First produced in the mid-19th century, it is stronger than cast iron and can be produced in large quantities, which has led to its widespread industrial use. Over the years, it has encouraged profound political, social and economic changes. Without steel we would not have had the Second Industrial Revolution or the Meiji Revolution in Japan. Brasília would have been nothing more than a sketch by Lúcio Costa and São Paulo would end up as an agricultural commercial center.

The book of Heroes and Heroines of the Homeland, which pays homage to key characters in the construction of Brazilian history, is known as the “Livro de Aço.”

But steel production became a problem. Currently, this $2.5 trillion global industry is responsible for 8% of greenhouse gas emissions. Even though it is a 100% recyclable material and can be recycled infinite times without losing quality, steel production is harmful to the environment and to the communities surrounding large industrial plants.

The solution lies in science and technology, once again. The steel industry has developed various strategies to go “green”, such as using green hydrogen instead of coal, using charcoal instead of coal, or carbon sequestration solutions. For example, in 2022 three Swedish companies (SSAB, LKAB and Vanttenfall) were the first to produce steel without using fossil fuels, using green hydrogen.

But these technologies have their limitations. For example, the use of green hydrogen requires the raw material to be a high purity iron ore (with less than 3.5% impurities), which corresponds to only about 20% of all available iron ore. on the market today.

The production of “green steel” is critical to ensuring the transition to a low carbon economy. For this reason, Boston Metal, a spin-off company from MIT in the USA, has gained prominence in the scientific and industrial community, which invented a solution known as MOE –Molten Oxide Electrolysis, or molten oxide electrolysis–, which consists of using electricity to transform raw metals into high purity molten metal products

Instead of carbon dioxide, the by-product is oxygen.

The company has already been praised by US Secretary of State Anthony Blinken and is financially supported by a fund that has capital from Bill Gates. If the 19th century was built with iron and the 20th century with steel, can the second goal of the 21st century be built with “green steel”?

Boston Metal’s scientific process is not without its doubts and questions, given its still pre-industrial character. The column spoke by email with Tadeu Carneiro, CEO of Boston Metal, about the difficulties in creating “green steel”. The interview was carried out within the scope of the campaign #science in the elections, which celebrates the Month of Science, an initiative of the Serrapilheira Institute.

If Boston Metal was founded in 2012, why is it taking so long to have the first industrial or semi-industrial cells and start commercializing the technology?

The company’s first six years were dedicated to exploring technology for different metallic systems. In this initial period, the company had six employees who developed the first pilot cell and made the first expansion of the electrolytic cell, leaving the bench cell developed at MIT. As of 2017, the company has focused its efforts on developing technology for the manufacture of high value-added ferroalloys and for the manufacture of steel. Since then the company has grown from six to 90 employees and has secured two additional successful funding rounds.

How can you ensure that Boston Metal’s technology enables the production of 100% green steel if the EOM implies the use of electricity? How to ensure that electricity is not generated with fossil fuels?

Steel produced with Boston Metal’s technology will only be 100% green if the electricity is green. The same goes for green hydrogen. It will only be green if the electricity is green.

In addition to being responsible for a significant part of global CO2 emissions, steel production is also responsible for significant amounts of contaminated wastewater and other hazardous solid waste. Will Boston Metal’s technology also contribute to the reduction of these other negative externalities, in addition to CO2?

Certainly. Boston Metal’s process does not use water in any of the steps and allows valuable metals to be extracted from industrial and mining tailings. In the manufacture of steel, the exhaust gas from the cells will be oxygen, which must be recovered as a by-product of the process. Excess electrolyte from iron ore impurities is completely inert and can be used as building material.

Can MOE technology be used in power plants currently in operation (coal-fired blast furnaces or steel scrap electric furnaces)? Or will new plants have to be built?

MOE technology will replace the entire initial stage of steel fabrication. The Boston Metal technology electrolytic cells will be built in place of the set that comprises the coal yard, the coke oven, the sintering and/or pelletizing of iron ore, the blast furnace, the torpedo cars that transport the pig iron and the BOF furnace that reduces the amount of carbon in the pig iron. A battery of electrolytic cells will replace this entire installation. The steel obtained from the cells will be much purer and will continue in the normal manufacturing process of the integrated plant, being transferred to ladle metallurgy, continuous casting and the entire process that follows in the manufacture of final steel products.

The process does not replace electric scrap melting furnaces. But the iron obtained with the Boston Metal process will complement the limited amount of scrap in the market. In addition, the product of the MOE process is pure and, therefore, will serve to dilute any contamination found in scraps that are remelted in current electric furnaces.

However, the most disruptive implementations of the technology will occur with the adoption of the same by iron ore suppliers. With the deployment of green energy in iron ore mines, ore suppliers will be able to use the technology to sell a metallic product instead of trading iron ore. They will increase the added value of your product and transport 40% less in mass. In addition, they will be able to process the material from their tailings dams to recover the iron contained in that material.

In addition to steel, what other metals can Boston Metal help to produce cleanly and efficiently? What is the relevance of these other metals?

The technology can be tuned to reduce the vast majority of metal oxides. Therefore, the electrolyte of the cells must be chosen according to the metal to be produced. Titanium, rare earths, chromium, molybdenum, niobium, tantalum, nickel and copper are examples of other metals of great importance for the sustainable future of the planet and that can be produced using Boston Metal’s technology.

What other technologies and scientific discoveries at the global level directly compete with the MOE?

Because it uses high temperatures, in which both raw material and products will be in a liquid state, and because it can use raw materials with reduced levels of oxides of the intended metal in its chemical composition, the process is unique in terms of expanding production capacity. . Furthermore, it is a modular process that allows it to be used in different production scales and in higher added value segments. In the specific case of steel production, the Boston Metal process is the only one capable of solving the problem of CO2 emissions for all types of iron ore on the market, as I mentioned earlier.