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Optimum temperatures for carbon deposition during integrated coal pyrolysis–tar decomposition (CVI ironmaking) Rochim B. Cahyono, Naoto Yasuda, Takahiro.

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Presentasi berjudul: "Optimum temperatures for carbon deposition during integrated coal pyrolysis–tar decomposition (CVI ironmaking) Rochim B. Cahyono, Naoto Yasuda, Takahiro."— Transcript presentasi:

1 Optimum temperatures for carbon deposition during integrated coal pyrolysis–tar decomposition (CVI ironmaking) Rochim B. Cahyono, Naoto Yasuda, Takahiro Nomura, Tomohiro Akiyama Center for Advanced Research of Energy & Materials, Hokkaido University, JAPAN Kuala Lumpur, Dec 12-14,

2 2  Steel consumption is one of indicators in prosperity and industrialization.  The steel demand would increase significantly to fulfill to economic growth in the potential countries such as China, Brazil, Indonesia and India  Steel consumption is one of indicators in prosperity and industrialization.  The steel demand would increase significantly to fulfill to economic growth in the potential countries such as China, Brazil, Indonesia and India Ref: [1] M. Walsh. Steel Logistics conference 2007, Hatch Beddows. [2] World steel association, Steel statistical yearbook [3] The Japan Iron and Steel federation. Research background Steel consumption and income per capita World crude steel production

3 3 [3] The Japan Iron and Steel federation. [4] Raw materials: High grade coal = 690 kg/ton-pig iron High grade iron ore = 1390 kg/ton-pig iron Limestone = 120 kg/ton-pig iron Iron and steel production Non-renewable resources Limited amounts Expensive Research background

4 4 Iron ore production and price Coal: reserves vs production Industrial worldwide CO 2 emission  Consumes around 5% of the total world energy[=24 EJ]  Energy recovery: 25.3% of input energy  CO 2 emission: 1519 kg-CO 2 /ton-pig iron Ref: [5] USGS, iron ore mineral commodity summaries ( ). [6] K. Morita, IEEJ 13 (2013), November issue. [7] IEA, worldwide trends in energy use and efficiency (2008).

5 Ironmaking problems Iron ore & coal Expensive & depletion Iron ore & coal Expensive & depletion Large emission of CO 2 Consume >10 % of Japan primary energy ResourcesEnvironment Energy Carbon cycling Less CO 2 emission High energy saving Waste heat utilization CH 4 CO 2 CO, H 2 Heat BF Cheap and stable supply Carbon netrual Biomass Low grade ore and coal Our solutions Pictures:

6 Solid fuels Utilization method Gasification/Pyrolysis Low grade iron ore Combined water High combined water (C.W.) content FeO·OH Problem Reduces the efficiency of low grade iron ore utilization. C.W. needs to be removed prior to ironmaking. Requires more energy Background Produces Char/cokeTar Gas mixture Useful fuel gases Useful solid fuel 6 Problem Clogs fuel lines, filters and engines. Reduces the efficiency of pyrolysis. Picture:

7 Porous ore (Fe 2 O 3 ) Heat treatment Decomposition of Combined water (330˚C) FeO ・ OH FeO H 2 O Ore partial reduction (Fe or FeO) Heat treatment FeO C (Fe + FeO) + CO CVI ironmaking Low grade iron ore (FeO-OH) Cheap Huge amount Ineffective utilization 7 Fast pyrolysis H 2, CO Tar C n H m Ore carbonaceous material (Fe 3 O 4 +C) CVI : Tar decomposition FeO C n H m (FeO C )+ CO + H 2 Solve tar problem and produce syngas (H2 and CO) Purposes:  Evaluate the temperature effect of tar decomposition on carbon deposition,. [11] Fuel Processing Tech. 113 (2013) 84-89; [12]

8 Consumption or production rate [PJ/year] IronmakingAustraliaIndonesiaJapanMalaysiaPhilippines Energy potential of biomass in southeast Asia, Australia and Japan are highly surplus with energy requirement of Japan steelmaking industry. Biomass potential of nearby Japan [27] Koopmans, A. Biomass Bioenergy 2005, 28, 133–150. The possibility of biomass energy utilization Exergy analysis and application of CVI process 8

9 9 Roles of CVI Ironmaking Carbon cycling by CVI process

10 10 Conventional catalystNew catalyst of proposed study Rare metal ( Pt, Ni, Rh... ) Ubiquitous elements (iron oxide) Manufactured productsNatural products (FeO·OH) ExpensiveUltra low-cost Carrier/supported requiredNo carrier/supported Nano-particles size Nano-pores within normal particles size (Dehydration of combined water) Not allowed of carbon deposition (deactivation) As much as possible of carbon deposition Long life Life is depend on pores and carbon deposition No recycling Attractive raw material in ironmaking industry (Low temperature and fast reduction) 1. Innovation on Catalyst development Roles of CVI Ironmaking

11 11 Conventional technologyThe proposed technology High-grade ore (Short-age resource and expensive) Low-grade ore (Huge resources and cheaps) Hard coking coal (Short-age resource and expensive) Low-grade coal and Biomass Ore-coke layers control (m ~ mm units) C-Fe-O in nano-scale contact (nm units) High-temperature reduction ( ˚C) Indirect reduction (FeO + CO = Fe + CO2) Low temperature and fast reduction (600˚C). Direct reduction (FeO + C = Fe + CO) Ore Coke Carbon m C-Fe 3 O 4 Composite Carbon Ore surface Nanopore nm 2. Innovation on development of ore/carbon composite in nano-scale contact Roles of CVI Ironmaking

12 12 CO2 undersea-underground storage Carbon cycle of the proposed Adsorption CO2 at low temperature (no waste recovery) CO2 is thermochemical process to reuse as reducing gas (CO) CO2 emission is transported to undersea reservoir (long way transport) CO2 emission is recycleed inside ironmaking (onside carbon cycling) There is no element to be co-producing a valuable resource Combined with CVI, co-production can produce C-Fe3O4 composite Large-scale facilities and high costSmall-scale facilities and low-cost 3. Innovation on CO2 reproduction technology Roles of CVI Ironmaking

13 Materials and experimental method Iron oreParticle size [mm]TFe [wt%]CW [wt%]Surface area [m 2 /g] Hamersley Raw materials: CoalFCVMAshCHNOS Lignite (LIGN) , Iron ore: 3 gram - Coal feed: 0.1 g/min - Total N 2 flow: 250 mL/min - Reaction time: 40 min Experiment conditions: Pyrolysis temp: 800 o C Tar decomposition temp: o C [13] Energy and Fuels 27 (2013) 2687–2692

14 14 Dehydration process (a) Micropore Macropore Mesopore  Removing H2O during dehydration process created porous ore with layer by layer structure  The micropore/mesopore was predominat in the dehydrated ore

15 15  HGC generated larger tar than other fuels which was essential for CVI process.  High amount of tar initiated large tar decomposition to produce gas product and deposited carbon within iron ore The total carbon yield was depend on the composition of original fuels. Product distribution 2.2. Relationship of solid fuels and CVI carbon deposition Process 2: Production of CVI ore/carbon composite [21] Cahyono, et al. Energy & Fuels 27 (2013) [16]

16 Tar decomposition Tar product distribution 16  At constant pyrolysis temperature, the maximum carbon content was obtained at tar decomposition of 600 o C.  At high temperature, deposited carbon decreased due to high tar activity and carbon gasification to produce larger gas product Highest deposition Unreacted tar

17  A higher temperature resulted in a large reduction degree because of indirect reduction of CO and fast reduction rate.  FeO was found at high temperature; this is consistent with the phase diagram. (b) (a) Tar decomposition 17

18 Tar decomposition 18 Smallest carbon deposition but largest deceasing of surface are and pore distribution, why??  The amount of carbon deposition should be proportional with the decreasing of surface area and pore size distribution.  The melting point of the iron ore (Fe 2 O 3 ) was 1733 K(=1460 o C) Sintering process [14] HSC chemistry 7.0; [15] Canovaa, IC. et.al. Materials Research Vol. 2, No. 3, (1999)

19 Reactivity of CVI ore ~nm The nano-scale contact between iron ore and carbon enhances the contacting area and results in the increasing of reaction rate Iron ore Carbon 19 Iron ore Coke (carbon) ~cm [16]

20 Reactivity of CVI ore  The carbonized ore was also useful and effective in the reduction reaction which was indicated by decreasing of carbon content during reduction reaction  The XRD result confirmed that the reduction reaction was started at o C Reduction of Fe 3 O 4 to FeO was started 20

21 Reactivity of CVI ore Transforming of iron compound in each experiment steps The final product of CVI ore can be sent directly to blast furnace and sintering machine Tar decomposition Direct reduction at 21

22 Conclusions  The highest deposited carbon was obtained at tar decomposition temperature of 600 o C.  At elevated temperature, the amount of deposited carbon decreased due to carbon gasification.  At tar decomposition temperature of 800 o C, the FeO was found but the sintering phenomena was started  The deposited carbon within iron ore showed promising candidate as good reducing agent due to higher reactivity and lower reduction temperature.  The reactivity of carbon-deposited ore increased because carbon deposited within iron pores and caused nanoscale contact between the iron ore and carbon. 22


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