Biotar Ironmaking Using Wooden Biomass and Nanoporous Iron Ore

Abstract

This paper describes fundamental experiments of a new biomass ironmaking that employs low-grade iron ore and woody biomass for promoting the direct reduction, FeO + C ) Fe + CO, in which dehydrated, porous limonite iron ore was filled with carbon deposited from the biomass tar, biotar. In our experiments, three types of iron ores containing different amounts of combined water (CW; 1.6, 3.8, and 9.0 mass %) were first dehydrated at 450°C to make them porous and then heated with pine tree biomass at 500-600°C for the gasification and the tar vapor generated was decomposed to deposit carbon within/on the porous ores. The dehydration treatment made the iron ores porous by removing CW and significantly increased their Brunauer-Emmett-Teller (BET) specific surface areas and porosities. In the second treatment of biomass gasification and decomposition of tar vapor, the biomass was changed into char, tar vapor, and reducing gas; the biotar was decomposed and carbonized within the porous ores. Interestingly, the ores caught biotar effectively, not only on the surface but also inside their pores. Here, the ores with the nanosized pores served as catalysts for tar carbonization with gas generation. Simultaneously, the ores were partially reduced to magnetite by the reducing gas. The ores containing carbonized material were easily reduced to iron by only heating until 900°C in a nitrogen atmosphere; this was due to the direct contact of carbon and iron oxide within the ores, so-called direct reduction. In conclusion, the dehydrated limonite iron ore was most effective for avoiding the generation of sticky tar in the biomass gasification and for filling the porous ore with carbon from tar. The product is a promising raw material for biomass ironmaking. The results appealed an innovative ironmaking method with a large reduction of carbon dioxide emission using low-grade iron ore and woody biomass.

Reduction Mechanism of Iron Oxide–Carbon Composite with Polyethylene at Lower Temperature

“…Many carbonaceous materials, such as coal, coke, biomass, and so on have been examined as possible reductants for the composites. [3][4][5][6][7] The focus has been on carbonaceous materials which can accelerate the reduction at lower temperature.…”

Analysis of Equilibrium-limited Dehydrogenation and Steam Reforming in Palladium Membrane Reactors

“…However, since no sweep gas can be used to provide the driving force for hydrogen permeation through the membrane, the partial pressure of hydrogen on the reaction side must be kept higher than that on the permeation side, which is usually maintained at atmospheric pressure or less 31) . Such a complicated reaction system has many operating parameters, so simulation and analysis for experimental results based on mathematical modeling are very useful to predict reaction characteristics inside the membrane reactor and to establish the optimum design and operating parameters for the membrane reactor to produce and recover more hydrogen.…”

Development process for tar filtering from biomass pyrolysis

“…This type of iron ore contains more gangue materials and combined water than those of high-grade iron ores [11,12]. Studies by Hata et al [13], Rozhan et al [14] and Cahyono et al [15] have reported that by heating these low-grade iron ores at temperatures less than 500°C, thermal decomposition of FeO(OH) removes the combined water, leaving the iron ore porous. However, additional thermal energy is required if low-grade iron ore is used directly in the iron-making process, which makes the utilization of low-grade iron ore less energy efficient.…”