Utilisation possibilities of biochar produced by pyrolysis
Viitasaari, Mirva (2021)
2021
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Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:amk-202105199435
https://urn.fi/URN:NBN:fi:amk-202105199435
Tiivistelmä
In the past decades there have been many efforts to reduce the burden humans have caused to the environment. One of these efforts is the utilisation of biomass as both energy and raw material, which offers a more sustainable option to meet the increased demand. This conversion of biomass can be achieved by pyrolysis which produces bio-oil, syngas, and biochar. Because of the unique properties and environmental benefits of biomass derived biochar, its utilisation possibilities seem to be very abundant.
The purpose of this thesis was to collect information on biochar characteristics and evaluate the chosen utilisation possibilities and their potential scalability. The theoretical section explores the pyrolysis process, biochar characteristics, the effect of pyrolysis, feedstock and upgrading methods to biochar properties. Also, evaluations of biochar use in blast furnace injection in metallurgy and as a catalyst in the concept of biomass refinery are conducted.
The key results indicate that the main parameters affecting biochar properties are pyrolysis temperature and feedstock. Generally important properties of biochar are mineral and ash content, porosity, pH, and density. The findings indicate that biochar can be a realistic commercial substitute for pulverized coal in blast furnace injection. Biochar can meet the quality requirement and was found to be comparable to pulverized coal. It offers a possibility to decrease emissions as a substitute of fossil coal and increase productivity in iron and steel industry. Biochar as a catalyst in thermochemical conversion of biomass offers a low-cost, more effective, and economic option for common catalysts used.
There are markets for biochar in worldwide and they are expected to grow. In Finland, markets also have a great potential, but large-scale production of biochar is missing. Thus, further studies are required to design an active and selective biochar catalyst. Moreover, the challenge of how to maintain certain biochar properties in a large-scale production needs to be met.
The purpose of this thesis was to collect information on biochar characteristics and evaluate the chosen utilisation possibilities and their potential scalability. The theoretical section explores the pyrolysis process, biochar characteristics, the effect of pyrolysis, feedstock and upgrading methods to biochar properties. Also, evaluations of biochar use in blast furnace injection in metallurgy and as a catalyst in the concept of biomass refinery are conducted.
The key results indicate that the main parameters affecting biochar properties are pyrolysis temperature and feedstock. Generally important properties of biochar are mineral and ash content, porosity, pH, and density. The findings indicate that biochar can be a realistic commercial substitute for pulverized coal in blast furnace injection. Biochar can meet the quality requirement and was found to be comparable to pulverized coal. It offers a possibility to decrease emissions as a substitute of fossil coal and increase productivity in iron and steel industry. Biochar as a catalyst in thermochemical conversion of biomass offers a low-cost, more effective, and economic option for common catalysts used.
There are markets for biochar in worldwide and they are expected to grow. In Finland, markets also have a great potential, but large-scale production of biochar is missing. Thus, further studies are required to design an active and selective biochar catalyst. Moreover, the challenge of how to maintain certain biochar properties in a large-scale production needs to be met.