Biomass gasification for natural gas substitution in iron ore pelletizing plants

• Published in: Renewable energy Vol. 81; pp. 566 - 577
• Main Authors: Carvalho, Mariana M.O., Cardoso, Marcelo, Vakkilainen, Esa K.
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-09-2015
• Subjects: Bio-synthetic natural gas; Biomass gasification; Iron ore pelletizing; Iron ore pelletizing; Biomass gasification; Bio-synthetic natural gas
• ISSN: 0960-1481; 1879-0682
• DOI: 10.1016/j.renene.2015.03.056

The ore fines' pelletizing is an important part of iron mining, which ensures better use of natural resources and increases the blast furnace efficiency. However, this process consumes high amounts of non-renewable energy, such as natural gas (NG) and coke. Due to fossil fuel scarcity and global warming issues, at least partial substitution for renewable energy is desirable. Biomass gasification projects are being successfully developed in Northern Europe and large-scale circulating fluidized bed (CFB) biomass gasifiers have been commissioned. This work compares different technologies, such as CFB air and oxygen gasification, dual fluidized bed (DFB) steam gasification, and bio-synthetic natural gas (bio-SNG) production, focusing on the use of the product gas in an iron ore pelletizing process located in the Southeast of Brazil. The main parameters evaluated were flame temperature and gaseous flow rates. Economical evaluation was also performed. Air gasification provided a product gas with the lowest energy content but it was the most attractive investment. Oxygen gasification is apparently the best option as it provides a product gas with higher heating value at almost the same cost as air gasification. In both cases changes to the burners would be required. Bio-SNG could be utilized without any adaption in the indurating machine; however, it is still more expensive than NG.
•This work evaluates the of biomass gasification as a substitute for natural gas in iron ore pelletizing processes.•Comparison was made between CFB air and oxygen, DFB steam gasification and bio-SNG production.•For all gasification processes except bio-SNG production, the energy consumption and gas flow in the kiln hood increase.•All processes evaluated appear to be economical feasible for total natural gas substitution except bio-SNG production.•This work can be expanded to other processes e.g. electricity production, pig-iron manufacturing, cement and lime kilns.