Research on Reduction of Fe2O3 by Biomass Sawdust

doi:10.1007/s12204-017-1833-5

Abstract

Abstract: The research on biomass reduction of Fe2O3 was carried out by using sawdust as reductant. The direct reducing agents in the biomass magnetization process were determined by comparing various biomass pyrolysis products with the reduction degree (divalent iron content in total iron), reduction temperature range and valence change of Fe2O3 in the reduction process. The microstructure variation of Fe2O3 at different stages was also analyzed by scanning electron microscopy (SEM). Nonisothermal thermogravimetric analysis (TGA) was applied to explore the thermal reduction process. The results show that the direct reducing substances in the biomass reaction with Fe2O3 are H2 and bio-oil, and the reduction process can be divided into two steps: biomass pyrolyzing to release H2 and bio-oil, and reductive volatiles reacting with Fe2O3. The two steps are relatively independent. The kinetic of the reduction reaction follows a first-order reaction kinetic model, with 88.99 kJ/mol activation energy and 9.55 × 108 min ?1 frequency factor.

Key words: biomass| reduction| Fe2O3| kinetics

摘要： The research on biomass reduction of Fe2O3 was carried out by using sawdust as reductant. The direct reducing agents in the biomass magnetization process were determined by comparing various biomass pyrolysis products with the reduction degree (divalent iron content in total iron), reduction temperature range and valence change of Fe2O3 in the reduction process. The microstructure variation of Fe2O3 at different stages was also analyzed by scanning electron microscopy (SEM). Nonisothermal thermogravimetric analysis (TGA) was applied to explore the thermal reduction process. The results show that the direct reducing substances in the biomass reaction with Fe2O3 are H2 and bio-oil, and the reduction process can be divided into two steps: biomass pyrolyzing to release H2 and bio-oil, and reductive volatiles reacting with Fe2O3. The two steps are relatively independent. The kinetic of the reduction reaction follows a first-order reaction kinetic model, with 88.99 kJ/mol activation energy and 9.55 × 108 min ?1 frequency factor.

关键词: biomass| reduction| Fe2O3| kinetics

CLC Number:

TF 111.13

LIU Xiaominga,b* (刘晓明), ZHANG Hongleia (张宏雷), LI Suqina (李素芹),LI Dongshenga (李东升), HUANG Dongboa (黄冬波). Research on Reduction of Fe2O3 by Biomass Sawdust[J]. Journal of shanghai Jiaotong University (Science), 2017, 22(3): 280-285.

References 16

[1]	JIN H Q, YANG H. Status and problems of China’siron ore imports and counter measures [J]. Globalization,2014 (4): 96-106 (in Chinese).
[2]	YE H, SUN X L. Analysis of the current situation ofiron ore import and its strategy [J]. Metal Mine, 2008(9): 7-10 (in Chinese).
[3]	EL-GUINDY M I, DAVENPORT W G. Kinetics andmechanism of ilmenite reduction with graphite [J].Metallurgical Transactions, 1970 (1): 1729-1734.
[4]	FEINMAN J. Direct reduction and smelting processes[J]. Iron and Steel Engineer, 1999, 6(6): 75-77.
[5]	PISA I. Combined primary methods for NOx reductionto the pulverized coal-sawdust co-combustion [J]. FuelProcessing Technology, 2013, 106: 429-438.
[6]	ZHANG H L, ZHU G C, YAN H, et al. Reduction oflow-grade manganese dioxide ore pellets by biomasswheat stalk [J]. Acta Metallurgica Sinica (EnglishLetters), 2013, 26(2): 167-172.
[7]	FU J X, ZHANG C, HWANG W S, et al. Explorationof biomass char for CO2 reduction in RHF process forsteel production [J]. International Journal of GreenhouseGas Control, 2012, 8: 143-149.
[8]	LUO S Y, YI C J, ZHOU Y M. Direct reductionof mixed biomass-Fe2O3 briquettes using biomassgeneratedsyngas [J]. Renewable Energy, 2011, 36:3332-3336.
[9]	GAN M, FAN X H, CHEN X L, et al. Reduction of pollutantemission in iron ore sintering process by applyingbiomass fuels [J]. ISIJ International, 2012, 52(9):1574-1578.
[10]	ZHANG M, YUAN Y C, LIU Y Z. Research onbiomass waste combustion technologies [J]. Energy Researchand Information, 2005, 21(1): 15-16 (in Chinese).
[11]	MUNIR S, DAOOD S S, NIMMO W, et al. Thermalanalysis and devolatilization kinetics of cottonstalk, sugar cane bagasse and shea meal under nitrogenand air atmospheres [J]. Bioresource Technology,2009, 100(3): 1413-1418.
[12]	XU D, ZHU G C, CHI R, et al. Investigation on dephosphorizationand magnetic separation of high phosphorousiron ore by biomass reduction roasting [J].Metal Mine, 2010 (5): 68-76 (in Chinese).
[13]	WANG Y B, ZHU G C, CHI R, et al. An investigationon reduction and magnetization of limonite usingbiomass [J]. The Chinese Journal of Process Engineering,2009, 9(3): 508-513 (in Chinese).
[14]	STREZOV V. Iron ore reduction using sawdust: Experimentalanalysis and kinetic modeling [J]. RenewableEnergy, 2006, 31: 1892-1905.
[15]	WU Y, FANG M, LAN L D, et al. Rapid and directmagnetization of goethite ore roasted by biomass fuel[J]. Separation and Purification Technology, 2012, 94:34-38.
[16]	COATS A W, REDFERN J P. Kinetic parametersfrom thermogravimetric data [J]. Nature, 1964,201(4914): 68-69.