Waste Heat Recovery and Power Generation

The metallurgical plant operators are exposed to severe cost pressures. On the one hand the electrical reduction furnaces require constant and high electrical energy, whilst on the other hand stable and profitable plant operation in turn requires stable and reliable powers supply. Unfortunately in many countries the availability and stability of the supply network is decreasing whilst the electricity prices are increasing. To add insult to injury carbon taxes and reduction in CO2 emissions add ever more pressure. To reduce costs and to reduce the dependency on external power input the plant operator can utilise the process gas to generate electrical power, provided that the gas is suitably cleaned and conditioned.

Flaring of the process gas

Flaring of instead of utilising the CO and H2 rich process gas

  • results in avoidable CO2 emissions
  • wastes useful resources
  • wastes money

Advantages of process gas utilisation

Integrating the thermal and calorific utilisation the process gas into the production process

  • reduces the operating costs
  • reduces the dependency on external heat and electrical input

Calorific versus thermal utilisation

The current technology in use only utilises a small portion of the process gas for heating and drying of raw materials and refractory materials. This is generally estimated at 40 %, which means that 60 % of the process gas is flared.

The latest innovation is to use this gas (after suitable conditioning) as a free fuel to run gas motor / generators sets. The advantages are:

  • independent and reliable generation of electrical energy
  • substantially reduced external power cost due to on-site generation of up to 35 % of the furnace requirement

THEISEN-technology for the calorific utilisation of the process gas

THEISEN provides modern concepts for green and brown field projects to condition the process gas thus providing a valuable fuel. For this purpose both proven technologies and innovative products are combined. The latest development is the THEISEN CDC.