Space exploration has brought many direct benefits to those of us who live on Earth, sometimes it is not even necessary to send a ship into space to achieve them. It could be the case of the Israeli company Helios, whose scientists were trying to find a way to create oxygen on the moon and found a way to produce green steel: a production method that minimizes industrial CO2 emissions.
A mammoth industry with huge emissions.
The steel industry is one of the most traditional industries, with roots deep in the industrial revolutions of the 19th century. The world produces some 2,000 million tons of this compound, most of it through the basic oxygen steelmaking system, a steelmaking method that is a direct heir to the Bessemer process created in 1850. A little less than a third of the production, on the other hand, is made by through the electric arc furnace, a method with less carbon dioxide or CO2 emissions.
CO2 emissions are in fact one of the great problems of this industry, which can generate twice as many emissions as the product (mostly indirect emissions due to the large amount of energy needed to heat the ovens). Current production is associated with 3,000 million tons of CO2, between 7 and 11% of global greenhouse gas emissions. The characteristics of the industry do not make innovation and risk taking very attractive, however it is necessary given the circumstances.
Need for alternatives to be cost-efficient.
Despite all this, there are many innovations that aim to decarbonise this industry. The problem is that not all of these measures are cost-efficient, so even if there are incentives for innovation, global development and implementation may fail. If the new processes are not more efficient or cheaper, it is unlikely that they will spread in a settled and static industry.
Diversity of alternatives.
Steel is produced through a series of combinations that culminate in the union of coke, a derivative of coal, with pig iron, the compound that contributes iron to the mixture. Basic oxygen steel mill furnaces use oxygen to extract excess carbon from the resulting mixture, creating the famous greenhouse gas. Electric arc furnaces are an essential piece in this process since their process generates fewer emissions at this point.
From there, there are several alternatives in different degrees of development. One of them is the one proposed by the Swedish project Hybrit. This method relies on hydrogen and electrical currents to replace coke and oxygen. The resulting emissions are water vapor. This is not a new process, but it is the first time it has been implemented in practice.
Another project, this one by Boston Metal, is based on what they have called molten oxide electrolysis. The company uses electrical energy to treat iron in its mineral form. Rocks containing iron usually contain it bound to oxygen. In steel production it is common to use carbon to clean this oxygen, which generates CO2. This system replaces carbon with electrical currents. Thus, the oxygen of the compound can be released, leaving the iron to be mixed, now yes, with the carbon necessary to produce the steel.
First zero emissions plant in Spain: 2025.
Emission-free steel already has a scheduled date to arrive in Spain, it is the year 2025, as announced by the company ArcelorMittal last year. It will do so by combining various techniques such as electric arc furnaces at the company’s plant in Sestao, greater use of recycled scrap as raw material and the use of hydrogen in the pre-treatment of iron at the company’s plant in Gijón . Indirect emissions will be avoided through the use of renewable energy sources, with the remaining emissions cut with “introduction of various key emerging technologies (…) such as sustainably produced biomass or green hydrogen”
There is one more alternative, that of carbon capture. This is not exclusive to the steel industry but can be used to reduce emissions, both direct and indirect. At present, capture technologies have been gaining prominence, although their implementation is not yet assured, among other reasons due to their high cost. However, they have the advantage that they do not require specific changes in the industrial process and can be implemented in almost any sector.
One of those happy accidents so common in science can add a new mechanism to this list, and its creators, the Helios company, assure that it is a superior alternative in economic terms to current processes.
The company’s scientists were trying to find a way to create oxygen from lunar rocks, regoliths, to avoid having to transport this gas from Earth. Oxygen is necessary for breathing but also to power rockets, and it is more practical to create it on site than to transport it in rockets. The surprise of the team of researchers was that their process to isolate oxygen generated large amounts of iron as a residue. If you look at it another way, this mechanism could generate iron as a primary result and oxygen as a waste product.
Road to zero emissions.
The company explains that this method eliminates direct emissions but, perhaps more importantly, halves the required energy consumption, and with it indirect emissions, which currently account for the majority of CO2 emissions from the industry. The great reduction in the energy required is what makes this method, according to the company, much more efficient and economical than the rest of the alternatives. Combining this procedure with renewable energy sources, the goal of zero emissions could be achieved.
The power source is key.
The decarbonization of metallurgy may be decisive in the years to come, but although we already have the technology, there are barriers to its implementation. Demand for steel is expected to continue to grow, so new, more efficient plants will not necessarily displace older, polluting ones.
This is added to what was already mentioned before, that since it is a heavy and traditional industry, changes are difficult and costly, although innovation is always necessary. Although new technologies reduce production costs, variable costs; the implementation, or fixed, costs involved in technological changes can make companies lean towards staying the same. Here both the possible tax incentives that countries can offer and the situation of the sector on the international scene come into play. If we add to this the great uncertainty with which the economy lives today, we find ourselves before a future that is not clear for the sector.
Image | Kateryna Babayeva