Biomasse als alternatives Reduktionsmittel in der Nichteisenmetallurgie

Translated title of the contribution: Biomass as an alternative reducing agent in non-ferrous metallurgy

Christian Dornig

Research output: ThesisDoctoral Thesis


In recent decades the emission of anthropogenically caused CO2 has led to an increase in average global temperature. Methods developed to reduce greenhouse gas emissions, such as the introduction of CO2 certificates, also affect the metallurgical industry. Due to the current rising prices of certificates, companies are more interested in alternatives to fossil carbon sources. This dissertation focuses on biomass as an alternative reducing agent in non-ferrous metallurgy and presents a possibility to minimize the use of fossil carbon carriers. Biochar produced during the pyrolysis of biomass has the advantage of very low sulfur content compared to petroleum coke, in addition to the CO2-neutral character. A product with a high carbon content can be obtained from woody biomass. Therefore, six different biochars from this type of biomass were characterized in the present work and tested for the usage in various metallurgical aggregates. Investigations concerning the use of biochar in the Waelz process showed that the reactivity plays a significant role. Applying the alternative carbon carrier the ZnO reduction worked well. However, the simulation of the heating phase during the furnace trials was challenging. The application of biochar instead of fossil carbon carriers for recycling lead slags proved to be promising, as better reduction results could be achieved with the pyrolyzed biomass. Pyrolysis gas is another product of the thermal conditioning of biomass and was treated in a reactor with liquid metal as a catalyst. Successful conversion into a gas with high proportions of CO and H2 was achieved, making its use as a reducing gas feasible. Biochar is currently more expensive than petroleum coke. However, subsidization by means of processed pyrolysis gas and trading of CO2 certificates could reduce the economic disparity between renewable and fossil carbon carriers. Based on the research and investigations conducted in this thesis, biochar is a partially suitable substitute and thus making a valuable contribution to CO2-neutral metallurgy.
Translated title of the contributionBiomass as an alternative reducing agent in non-ferrous metallurgy
Original languageGerman
Awarding Institution
  • Montanuniversität
  • Schenk, Johannes, Co-Supervisor (internal)
  • Antrekowitsch, Jürgen, Supervisor (internal)
  • Steinlechner, Stefan, Assessor A (internal)
  • Lehner, Markus, Assessor B (internal)
Publication statusPublished - 1800

Bibliographical note

embargoed until 19-02-2029


  • biomass
  • biochar
  • alternative reducing agent

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