Conversion of Injected Forestry Waste Biomass Charcoal in a Blast Furnace: Influence of Pyrolysis Temperature

Energy & Fuels, vol. 35, pp. 529–538

Abstract

The objective of this work is to study the influence of pyrolysis temperature on the combustion behavior of biomass-derived charcoal under conditions that simulate tuyere injection operations in a blast furnace ironmaking process. These results are compared with those for conventional pulverized coal. Pinus radiata chips have been pyrolyzed in a screw continuous reactor at 300, 500, 700, and 900 °C, and the vapors obtained have been thermally treated in a second reactor at 800 °C. The charcoal has been characterized, including its chemical composition as well as its textural characteristics. Tuyere injection combustion behavior tests of the charcoal and pulverized coal have been performed under different oxygen-to-carbon ratios in a batch injection rig reactor at 1700 °C for 20 ms, charcoal in its initial sample size distribution (45–2000 μm) and both ground to 90–125 μm. It has observed that increasing pyrolysis temperature results in lower charcoal yields, decreasing its volatile matter and oxygen contents and increasing the carbon content. Concerning the influence of temperature, the higher the pyrolysis temperature, the lower the influence of the injection rate on the charcoal combustion is. It has proven that 45–2000 μm particle size charcoal shows a greater conversion degree than 90–125 μm ground charcoal in the injection rig reactor, except for 900 °C charcoal, regardless of the particle injection rate. The conversion degrees of the 45–2000 μm particle size charcoal produced at 300, 500, and 700 °C are similar, being these data much greater than that of pulverized coal at any injection rate. The conversion degree of 900 °C original charcoal is not affected by the increase of oxygen-to-carbon ratio, showing conversion higher than that of pulverized coal for only high injection rates, which include values typically used in industries.

Authors 8

1. Jon Solar

   University of the Basque Country

   Affiliation as printed

   Chemical and Environmental Engineering Department, School of Engineering of Bilbao, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo, 1, 48013 Bilbao, Spain

2. Frederik Hippe Aachen Department of Ferrous Metallurgy Institut für Eisenhüttenkunde

   RWTH Aachen University

   Affiliation as printed

   Department of Ferrous Metallurgy, Institut für Eisenhüttenkunde, Rheinisch-Westfälische Technische Hochschule (RWTH Aachen), Intzestraße 1, 52072 Aachen, Germany

3. Alexander Babich Aachen Department of Ferrous Metallurgy Institut für Eisenhüttenkunde

   RWTH Aachen University

   Affiliation as printed

   Department of Ferrous Metallurgy, Institut für Eisenhüttenkunde, Rheinisch-Westfälische Technische Hochschule (RWTH Aachen), Intzestraße 1, 52072 Aachen, Germany

4. B.M. Caballero corresponding

   University of the Basque Country

   Affiliation as printed

   Chemical and Environmental Engineering Department, School of Engineering of Bilbao, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo, 1, 48013 Bilbao, Spain

5. I. de Marco

   University of the Basque Country

   Affiliation as printed

   Chemical and Environmental Engineering Department, School of Engineering of Bilbao, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo, 1, 48013 Bilbao, Spain

6. Carmen Barriocanal

   Instituto Nacional del Carbón

   Affiliation as printed

   Instituto Nacional del Carbón (INCAR-CSIC), Apartado 73, 33080 Oviedo, Spain

7. Alexander López-Urionabarrenechea

   University of the Basque Country

   Affiliation as printed

   Chemical and Environmental Engineering Department, School of Engineering of Bilbao, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo, 1, 48013 Bilbao, Spain

8. Esther Acha

   University of the Basque Country

   Affiliation as printed

   Chemical and Environmental Engineering Department, School of Engineering of Bilbao, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo, 1, 48013 Bilbao, Spain