Carbon Deposition from Biotar by Fast Pyrolysis Using the Chemical Vapor Infiltration Process within Porous Low-Grade Iron Ore for Iron- Making Alya N. Rozhan, †,‡ Rochim B. Cahyono, †,§ Naoto Yasuda, † Takahiro Nomura, † Sou Hosokai, ∥ Hadi Purwanto, ‡ and Tomohiro Akiyama* ,† † Center for Advanced Research of Energy Conversion Materials, Hokkaido University, North 13 West 8, Kita-ku, Sapporo, 060-8628, Japan ‡ Department of Manufacturing and Materials Engineering, Faculty of Engineering, International Islamic University, 50728 Kuala Lumpur, Malaysia § Department of Chemical Engineering, Gadjah Mada University, JI. Grafika 2, Bulaksumur, Yogyakarta 55281, Indonesia ∥ Energy Technology Research Institute, Advanced Industrial Science and Technology (AIST), AIST Tsukuba West 16-1, Onogawa, Tsukuba, Ibaraki, 305-8569, Japan ABSTRACT: This paper presents a technology for iron-making using biomass and a low grade iron ore by implementing chemical vapor infiltration (CVI) for the tar carbonization process. In this process, tar vapor from pyrolysis of biomass was infiltrated within a porous ore and carbon deposition occurred on the pore surface. For preparation, ore sample was heated in an electric furnace to decompose combined water in the sample, creating nanosized pores. In the experiments, the traditional slow pyrolysis was compared with fast pyrolysis to determine which condition is better for maximizing carbon deposition. Tar vapor from the pyrolysis process was introduced into the porous ore and trapped inside it, where tar decomposed and carbonized within the pores. The product of this process which is a carbon−magnetite composite with close arrangement of iron ore and carbon is useful for reduction of iron by carbon and is able to lower the temperature needed for reduction of iron to occur, as compared to that in steelworks. The purpose of this research is to compare the effects of slow pyrolysis and fast pyrolysis processes on the amount of carbon deposited within iron ore by the tar carbonization process and to observe the reduction reactivity of the carbon-deposited iron ore. 1. INTRODUCTION Steel has been produced for centuries, and many improvements in its production have been made to date. In our modern world, steel utilization is vital to ensure a more sustainable future. With over 1.3 billion tons of steel being produced each year, it is possible to expect a strong continuing growth in steelworks, particularly in developing countries where more than 60% of steel is used to make new infrastructure. 1 Today, the major challenge in steelworks is depletion of high-grade resources and finding alternatives to these high-grade sources as the raw materials in steel work is indeed crucial. 2 Due to depletion of high grade resources, it is necessary to use low grade iron ores extensively in the iron-making process. As compared to high grade iron ores, low grade iron ores contain more gangue minerals and combined water since the major component is goethite, FeO·OH. 3 Because of that, when heated, the specific surface area of ore increases due to thermal decomposition which leaves the iron ore porous. 4−7 However, this requires additional thermal energy in steel works which makes the utilization of low grade iron ore less energy efficient. 8 Therefore, alternatives to utilize low grade iron ore efficiently are essential. In the iron-making process, a blast furnace is the most important reactor and is expected to remain being so for many years to come. In this industry, coal is widely used in a blast furnace as a fuel. It is a nonrenewable fuel, which is being mined at coal mines. So, it is important to understand that the use of renewable resources is necessary as we know that the fossil reserve is limited at present. 9 Biomass being an important renewable energy source has the highest potential toward sustainable development in the near future. 10 Generally, biomass is utilized by thermochemical processing with the use of heat and catalysts to be transformed into fuels, chemicals, or even electric power. Recently, studies have been made to utilize agricultural waste 11 and polymeric materials 12 in the electric arc furnace steelmaking process. Both studies show the efficiency of these agricultural waste and polymeric materials to be used as a partial replacement of coke in electric arc furnace steelmaking. One of the promising thermochemical processes to utilize biomass is by the pyrolysis process. Pyrolysis produces useful fuel gases, char, and tar. 13 Tar, which has been an unwanted constituent in this process, causes a problem since it clogs fuel lines, filters, and engines, thus reducing the utilization efficiency of biomass. Even so, decomposition of tar gives carbon deposition which is useful and attractive to be collected and used as a fuel source. 14,15 This carbon is sometimes being referred to as pyrocarbon, 16 carbon-rich dust, or soot. 17 Received: August 28, 2012 Revised: November 7, 2012 Published: November 7, 2012 Article pubs.acs.org/EF © 2012 American Chemical Society 7340 dx.doi.org/10.1021/ef301409f | Energy Fuels 2012, 26, 7340−7346