Carbon cycle

An integrated metallurgical plant consists of a coking plant, blast furnace, converter steelworks, and auxiliary and further processing facilities. Nowadays, Europe’s integrated metallurgical plants use all of the process gases from steel production. Most of the gases are used in power stations to generate electrical energy. Many plants are now self-sufficient and place hardly any further strain on the network infrastructure.

Metallurgical gases are produced in the blast furnace, converter steelworks, and coking plant. They contain nitrogen, carbon monoxide, carbon dioxide, hydrogen, methane, and traces of other gases. The composition depends on the place of origin and also varies within the production processes. This makes metallurgical gases from steel production a challenging raw material for the chemical industry. The preparation and conditioning of the gases are particularly important as the synthesis processes in the chemical industry do not function without them.

The CO₂ emissions from the production activities of one company represent the raw material source of the next company. In Carbon2Chem^®, the coupling takes place using the example of the steel and chemical industries and power generation. The aim is a transfer to other CO₂-intensive industries.

The metallurgical gases from steel production are to be used for syngas production. Syngas is a chemical precursor from which various chemicals can be produced. Methanol, urea, higher alcohols, and polymers are examples of this.

Syngas is a gas mixture of carbon monoxide and hydrogen or of nitrogen and hydrogen. It is primarily used to produce methanol, ammonia, and other basic chemicals. Syngas has so far been produced from fossil raw materials, e.g. by means of coal gasification and the cracking of natural gas and crude oil.

Ammonia can be produced from nitrogen and hydrogen. Ammonia becomes an important building block for feeding a large proportion of the world’s population by integrating CO₂ urea, which is used, among other things, to produce mineral fertilizers.

The carbon compounds carbon monoxide and carbon dioxide as well as hydrogen form the basis of the basic chemical methanol. Methanol can be used to drive cars, fly airplanes, or produce other chemicals. The carbon required to produce methanol is currently mainly provided by fossil sources such as natural gas. At Carbon2Chem^®, it comes from metallurgical gas.

At Carbon2Chem^®, metallurgical gases are used not only to generate electricity but also as a new source of raw materials for the production of chemical recycling materials. This has the advantage that the proportion of metallurgical gas used for chemical production is no longer burned and less carbon dioxide (CO₂) is produced. The carbon is used in chemical production for a second time in the form of CO₂. This means less strain on the climate and reduces the use of fossil raw materials in chemical production.

Carbon2Chem^® uses large quantities of hydrogen for the chemical processes involved in the production of ammonia and methanol. The quantity available in the metallurgical gases is not sufficient. Hydrogen can be produced in an environmentally friendly manner using water electrolysis, in which water is split into oxygen and hydrogen using electricity. The electricity should be obtained from renewable sources. This means that the environment will not be polluted with additional carbon dioxide during production.

Current peaks are still a challenge for the energy system today. Carbon2Chem^® offers the possibility of using large industrial plants such as steel and chemical plants as energy buffers.

The production of chemicals and, above all, hydrogen is being driven dynamically in order to be able to react to the supply of renewable energy sources in line with demand. The flows of metallurgical gas are divided here so that one part is still available for steel production and the other part for chemical production using renewable energies. This concept is called load management or demand-side integration. Carbon2Chem^® thus stabilizes the electricity grid and contributes to the energy transition.