Carbon in Urbanization

The global population and thus major metropolitan areas are growing rapidly making basic materials such as steel and aluminum especially valuable. Carbon is a major contributing factor for optimizing production and recycling of these materials.

Today the world's great urban centers already accomodate many more inhabitants than rural areas and this trend is anticipated to increase in the future, posing major challenges for us, such as efficient and ecological use of our natural resources. In many industries carbon is a key material for applications involving steel, aluminum or other chemical substances, and its exceptional properties provide an excellent basis for meeting the challenges of progressive urbanization.

Our extensive experience with carbon has placed us in great demand as an industrial partner, because our overall approach offers more than just familiarity with the possibilities of using this material: We offer customers integrated concepts and customized system solutions from one company to ensure improvement of existing technologies and processes for sustained growth even in mature markets.

World population

0 bn.
people in 2012,
51% live in the cities
0.6 bn.
people in 2050,
70% live in the cities

Scrap becomes steel. Recycling in an arc furnace.

Steel is by far the most important construction material, forming the basis for industrialization, and shows high demand in rapidly emerging economies, particularly in China. Approximately 50 percent of the world's steel is produced in the world's most highly populated country. The quantity of raw materials required is proportional to the increasing size of the cities – which themselves possess gigantic resources in the form of materials used for their construction. From an ecological point of view steel is an excellent material which can be repeatedly recycled from steel or iron scrap without reducing the quality. And another climate-friendly advantage is the fact that recycling steel produces 80 percent less CO2 than melting iron ore.

New steel is produced from scrap in an electric arc furnace (EAF). Graphite electrodes weighing several tons and several meters long conduct the electricity required to melt the scrap into the gigantic furnace where temperatures of over 3,000 degress Celsius prevail. No other materal can withstand such temperatures. At increasing temperature graphite not only becomes harder; its conductivity also increases. SGL Group produces electrodes and connecting pins to serve as connecting elements between the electrodes. The cylindrical electrodes are produced with diameters of up to 800 millimeters.

Moreover we also offer steel works comprehensive services for optimization of their processes. This also includes the Customized EAF Data Information System, abbreviated CEDIS®, for individual recording and analysis of the arc furnace production and control data. Together with technical experts from SGL Group this provides customers valuable support for increasing the productivity of their smelting process.

Optimization of aluminum production

From high-efficiency power cables and lightweight structures in the transport sector to IT products and intelligent packaging – aluminum is everywhere in our cities. And it is becoming increasingly important due to advancing urbanization. Yet the production of primary aluminum is an extremely energy-intensive process in which carbon plays an important role. Carbon and graphite cathodes serve as the power supply and bottom of the electrolytic cell.

As a leading cathode manufacturer, SGL Group supports the aluminum industry with patented solutions for increasing energy efficiency. Examples include the application of SIGRAFLEX® graphite foils, a variable slot depth, and new materials. All of these developments reduce specific energy consumption and increase the operating life of the cathodes. After all, these are high-quality investment goods that only have to be replaced every five to seven years on average.

We have developed a novel measuring method that makes it possible for us and our customers to accelerate development cyles and fully utilize the cathode operating life. Its advantage is that it can be applied during the running production of aluminum. The wear profile of the cathode surface is quickly, precisely, and reliably determined using this method. This data helps us draw conclusions as to the remaining life of the cell, to determine the durability of a new material early on, and to create a new cell design. The result is shorter technology development cycles and better utilization of the remaining cell life, which in turn leads to improved profitability for each electrolytic cell.

Heat exchangers for
corrosive media

They are everywhere in our everyday life: plastics. In their production, the chemical industry works with various corrosive substances, such as hydrochloric acid. SGL Group designs and builds facilities and equipment for the chemical industry, especially for applications with corrosive media. One example is our DIABON® heat exchanger. There are up to 2,000 graphite tubes in such a heat exchanger. In almost no time at all, they transmit enormous amounts of heat from one medium to another. They can thereby heat up or cool down even the most aggressive substances with incredible efficiency. The chemical industry uses them in the production of materials such as polyvinyl chloride (PVC) and plastic foams.

Reactors for decomposing CFCs

Chlorofluorocarbons (CFC) are used as propellants and refrigerants. Old refrigerators, for instance, often still contain CFCs. Today these gases are usually banned, and for good reason: Their effect on our climate is up to 15,000 times stronger than that of carbon dioxide. Old refrigerators still contain large amounts of CFCs, which have to be separated carefully and destroyed. SGL Group has developed process units that thermally decompose CFCs before they can leak out into the environment. The core of such facilities is a so-called porous reactor. At temperatures of over 1,500 degrees Celsius, the units completely destroy CFCs and recapture valuable hydrofluoric acid. This technology is enabled by a special graphite that is extremely resistant to aggressive gases and acids.