Electricity generation from waste heat

Fermentation is created in numerous technical processes and often fizzles out into the atmosphere unused. In the meantime, an attempt is also made to use them as a source for heat supply in buildings and for electricity generation.
The generation of electricity is generated in the ORC process (Organic Rankine Cycle). This technology is not new. It has been used since the 1960s. In the meantime, it has been improved and is becoming increasingly important in view of the high energy prices, strict CO2 requirements and climate change. Low temperature downheat is converted into electricity.

Savings potential through industrial waste heat

Every day, huge amounts of energy in cement works, steel factories and foundries fizzle out. The energy released in the form of waste heat could provide climate -friendly electricity. This is possible with ORC technology, which works like a classic steam power plant.

The German Energy Agency (dena) expects the use of industrial waste heat to generate electricity with a savings potential of approximately 450 petajoules or 125 terawatt hours.

This means annual cost savings of around 5 billion euros. So waste heat is not an energetic waste, but it can cover the electricity requirements in industry cheaper and more climate -friendly.

How an ORC system works

An ORC system uses waste heat between 90 and 500 degrees Celsius for electricity generation. The base is the Rankine district process. It is a thermodynamic process that converted heat into mechanical work. A steam turbine uses an organic working medium instead of water that evaporates at low temperatures.

Warms often arise at a temperature level that is too low for the operation of classic steam turbines. However, waste heat can be used for ORC procedures. No water vapor is used as a tool, but organic liquids or refrigerants with a lower boiling point as water. A turbine can be operated even at lower pressure and lower temperatures. Since more compact systems can also be built, smaller waste heat sources can also be opened up.

In the ORC process, an organic liquid circulates as a medium in a closed cycle. The liquid is heated and evaporated by the supply of waste heat. Werthms can be supplied as hot air, hot water or steam.

The steam comes into the expansion machine. It turns and drives a generator that generates electrical stream. The organic liquid condenses in a downstream cooler. The condensate is led to the heat source again. The cycle begins again.

Advantages of an ORC system

An ORC system generates electricity from thermal energy. It offers a high savings potential and works efficiently. It makes an important contribution to sustainable supply strategies. Companies can benefit from several advantages.

Energy saving and high economy

In view of the increasing energy costs, the conversion of waste heat into electricity can be economical. It helps companies save energy costs. However, an exact analysis of the company is important.

ORC systems are particularly suitable for companies with running times of more than 5,000 full load hours per year.

The system then often pays off after a few years. ORC systems are suitable for energy-intensive industries that include cement, glass, metal and chemical industry. Unused waste heat can be used economically in these companies.

Lower electricity requirement and fewer carbon dioxide emissions

Companies reduce their external electricity cover when they convert the waste heat generated into electricity with an orc system. Companies reduce their energy costs in the long term.

With an ORC system, companies contribute to climate protection and decarbonization. You need fewer fossil fuels and lower your CO2 emissions. Similar to a photovoltaic system, electricity can also be generated with an ORC system that is not required immediately. It can be fed into a public power grid and remunerated.

Planning security and reliability

A modern ORC system is characterized by a low maintenance effort and is considered technically reliable.

It enables companies to calculate stable their costs and savings potential and ensure planning security.

When does an ORC system make economic sense?

An ORC system is not economically sensible for every company. It is economical if the waste heat has a temperature of at least 100 degrees Celsius, but better over 200 degrees Celsius. In addition, there should be a high number of full load hours per year.