As you may have read, the steel industry is undergoing rapid and radical changes. In the coming years most production processes relying on blast furnaces and BOF converters will be replaced by alternative routes with no more dependence on fossil carbon (cokes) and in many cases mainly fueled by hydrogen. The reason: steel production can be held responsible for about 7% of all global CO2 emissions [1,2]. As a result many sites have planned in billion-euro investments to radically change the way steel is produced, making some of the existing assets obsolete, while many new installations will need to be built.
This is a challenging operation, as most will have to happen on active production sites. An additional challenge is: some of the installations in use today have reached the end of their operational life. It would in that case not be smart to invest in new assets, as the plan is to have the new production lines active 2 - 4 years from now. The existing installations will thus have to bridge this period: a prolonged operational life.
This is not always a trivial operation. An interesting solution to make this happen? A close follow-up (monitoring) of these assets with as a goal detecting damage and issues in an early stage and take corrective measures well ahead of time. The ones that will leave service are BOF converters, blast furnaces, their charging installations, some overhead cranes in the steel plant, coke plants and the supporting installations… In the context of lifetime extension these can be equipped with various sensors collecting data that is converted into indicators about structural health and component integrity through smart algorithms. As a result one can rest assured that installations will not suddenly become unavailable. Component degradation on motors, gearboxes… will become apparent in an early stage, such that repairs can be planned in well ahead of time. Structural damage, like cracks, is detected rapidly, and operating conditions resulting in crack growth can be identified and avoided.
The goal: lifetime extension in a controlled way, without additional risk. But if done well, this can even come with a bonus, under the form of maximal availability of the instrumented installations.
The ultimate path forward to CO2-free steel production will be either a hydrogen-based approach, or a wet (hydrometallurgical) one. Items to be taken into account are:
- There must be sufficient amounts of green electricity available to power the EAF as well as the other parts of the process
- The need for so-called pellets in the production phase imposes certain restrictions on ore grades and supply
- Hardware and site lay-out: all will change drastically, and the way the installations are operated will be drastically different, so a lot of (re) training will be required.
- There must be sufficient hydrogen available, and this hydrogen should also be produced using a carbon-neutral process.
- Process modification: in order to be able to produce specific alloys or steel grades, processes taking place on a site today may also have to be heavily re-designed
- Price: in a first instance steel produced through this route will be more expensive. This will have to be accounted for somewhere in the economical system
Would you be interested in digging deeper in this topic: A recent report by McKinsey  put some numbers together.