MAKSTIL is a steelwork located in Skopje, North Macedonia, employing over 1,000 people. Unlike traditional steelworks, which use iron ore and a blast furnace, MAKSTIL uses scrap metal as raw material. The basic process is as follows: First an electric arc furnace melts scrap metal and in a ladle furnace the liquid steel gets refined to the desired quality. In the next step a continuous casting process forms so called steel slabs, a semi- finished product. In the plate mill those slabs are reheated and finally rolled and cut to the dimensions needed. The finished product is so called hot rolled plates. Those steel plates are exported in over 40 countries and will be used in ship construction, in mining and industrial machinery and for example windmill structures.
Interesting facts on steel recycling (EuRIC AISBL, 2020):
- About 90% of steel is collected and recycled at the end of life in Europe.
- Recycled steel reduces CO2 emissions by 58% and saves 72% of the energy needed for primary production.
- Roughly 70 % of all the steel produced up to date is still in use.
Increased efficiency through EBT-system:
The Energy Scouts Eleonora Jovanovska and Tijana Shaleva, both electrical engineers by education, focus on the energy perspective. When looking for a practical project as part of their Energy Scout training, they thought big – really big. Both knew that the electric arc furnace – the core process – encounters operational inefficiencies, impacting the productivity and energy efficiency. The operation of tilting a furnace to pour molten steel is called “tapping”. The existing Spout Tapping system leads to substantial heat lossand therefore increased energy consumption, accelerated consumption of electrodes and refractory materials as well as higher steel losse as slag is tapped into the ladle. Additionally, logistical challenges, including longer Time is crucial for productivity.
To address these challenges and improve energy efficiency and productivity while reducing costs and environmental impact, the Makstil team plans to convert the electric arc furnace to a so called Eccentric Bottom Tapping (EBT) system. EBT leads to low slag or even slag-free tapping and shorter tap-to-tap times. It also reduces electrode consumption and improves ladle life.
The transition to the EBT-system occurs in multiple phases:
The implementation of the EBT system conversion at the Electric Arc Furnace (EAF) will proceed in several phases. The first phase includes an analysis of the current operations and preparation for the integration of the new system. The installation of the EBT system will follow, which will involve testing the new equipment and training of staff. The project will be executed with minimal disruption to production processes to ensure the smooth operation of the production lines.
Potential energy and cost savings:
In terms of energy savings, the new system is likely to reduce electricity consumption by 40 kWh per ton, resulting in annual cost savings of roughly 1 million euro for electricity alone. Additionally, there will be less consumption of electrodes, refractory material, aluminum and other material, further reducing operational costs by 1 million euro per year. After only 2.58 years, the investment pays off and creates long-term savings over an estimated period of 15 years, assuming regular maintenance.
In addition to the economic benefits, the project will have a positive environmental impact: The reduction in electricity consumption will lead to a decrease in CO₂ emissions by approximately 6,697.53 tons annually, a big step towards a more sustainable and environmentally friendly operation.
Process Optimization
- Industry Sector: metal industry
- Energy Source: electricity
- Electricity savings potential: 11,896 MWh/year
- CO2 emissions savings potential: 6,697 tons CO2 /year
- Potential cost reduction: 2,131,441 €/year
- Investment costs: 5,500,000 €
- Payback period: 2.58 years
- Company:
MAKSTIL AD
16 Makedonska brigada, 18
1000 Skopje
Republic of North Macedonia
www.makstil.com
Eleonora Jovanovska and Tijana Shaleva summed it up:
“Being Energy Scouts allows us to apply theoretical knowledge in practice and face real challenges in our production processes. We create a specific solution, which will have a direct impact on energy efficiency and the sustainability of Makstil. We further developed important skills such as problem-solving, application of innovations and worked with a big team from various departments. In addition, we familiarize ourselves with the latest technologies and methods in energy management, which is crucial for our professional careers. We are looking forward to measuring the effectiveness of the applied solutions and present the results to management.”
Their practical project convinced the jury because of its impressive impact and savings potential, awarding Eleonora and Tijana with “Best Energy Scouts of the year” of North Macedonia.