LOW-RANK COAL GASIFICATION USING A BUBBLING FLUIDIZED BED REACTOR AT LOW OPERATING TEMPERATURE
DOI:
https://doi.org/10.30556/imj.Vol22.No2.2019.927Keywords:
low-rank coal, gasification, bubbling fluidized bed, producer gasAbstract
Coal gasification is one of coal utilizations that produces less CO2 emission than coal combustion. Coal gasification technology that has been used in Indonesia is generally a fixed bed gasification. Fixed bed is designed for high-rank coal and the majority of Indonesian coal is of a low-rank. Low ash and high moisture content of the Indonesian coal in a fixed bed can affect mechanical and thermal fragmentation, pressure drop, gas and particle flow distribution. The operation of gasifier may cause unstable condition. Another gasification technology is bubbling fluidized bed, which is operated above 1,200°C, so ash can melt. High operating temperature causes agglomeration and makes unstable gasification process. Therefore, in this study, low-rank coal is gasified in bubbling fluidized bed reactor at low operating temperature. The purpose of this study is to determine the optimal conditions of bubbling fluidized bed gasification. The research was conducted in bubbling fluidized bed coal gasification Process Development Unit (PDU) at Coal Utilization Technology Centre of R&D Centre of tekMIRA, Palimanan. Coal was fed continuously as many as 20 kg/hour into a gasifier then was gasified to produce gas using air as a gasifying agent and silica sand as a bed material at 850- 950°C. The produced gas from the gasification was analyzed using the Orsat Analyzer. A simulation using a ChemCAD 7.1 CC steady state was applied to validate the experiment result. From the analyzed result of yield gas composition, the produced CO and CO2 were about 10-15 wt%. Gas compositions that are close to criteria of producer gas, no agglomeration, and stable process condition during study indicate that bubbling fluidized bed gasification at low operating temperature is suitable to be applied as gasification technology for Indonesian low-rank coal.References
Bell, D. A., Towler, B. F. and Fan, M. (2011) ‘Gasifiers’, in Coal Gasification and Its Applications. Elsevier, pp. 73–100. doi: 10.1016/B978-0-8155-2049-8.10004-X.
Bu, C. et al. (2014) ‘Ignition behavior of single coal particle in a fluidized bed under O2/CO2 and O2/N2 atmospheres: A combination of visual image and particle temperature’, Applied Energy, 115, pp. 301–308.
doi: 10.1016/j.apenergy.2013.10.040.
Coppola, A. et al. (2014) ‘Hydration-induced reactivation of spent sorbents for fluidized bed calcium looping (double looping)’, Fuel Processing Technology, 120, pp. 71–78. doi: 10.1016/j.fuproc.2013.12.004.
Dutu, R. (2016) ‘Challenges and policies in Indonesia’s energy sector’, Energy Policy, 98, pp. 513–519. doi: 10.1016/j.enpol.2016.09.009.
van Eyk, P. J. et al. (2016) ‘Control of agglomeration during circulating fluidized bed gasification of a South Australian low-rank coal: Pilot scale testing’, Energy & Fuels, 30(3), pp. 1771–1782. doi: 10.1021/acs.energyfuels.5b02267.
Harris, D. J. and Roberts, D. G. (2013) ‘Coal gasification and conversion’, in The Coal Handbook: Towards Cleaner Production. Elsevier, pp. 427–454. doi: 10.1533/9781782421177.3.427.
Judex, J. W., Gaiffi, M. and Burgbacher, H. C. (2012) ‘Gasification of dried sewage sludge: Status of the demonstration and the pilot plant’, Waste Management, 32(4), pp. 719–723. doi: 10.1016/j.wasman.2011.12.023.
Luckos, A. and Bunt, J. R. (2011) ‘Pressure-drop predictions in a fixed-bed coal gasifier’, Fuel, 90(3), pp. 917–921. doi: 10.1016/j.fuel.2010.09.020.
Mahinpey, N. and Gomez, A. (2016) ‘Review of gasification fundamentals and new findings: Reactors, feedstock, and kinetic studies’, Chemical Engineering Science, 148, pp. 14–31. doi: 10.1016/j.ces.2016.03.037.
Manyà, J. J. et al. (2006) ‘Influence of gas residence time and air ratio on the air gasification of dried sewage sludge in a bubbling fluidised bed’, Fuel, 85(14–15), pp. 2027–2033. doi: 10.1016/j.fuel.2006.04.008.
Patel, V. R., Upadhyay, D. S. and Patel, R. N. (2014) ‘Gasification of lignite in a fixed bed reactor: Influence of particle size on performance of downdraft gasifier’, Energy, 78, pp. 323–332. doi: 10.1016/j.energy.2014.10.017.
Qian, F. et al. (2013) ‘Development of a kinetic model for industrial entrained flow coal gasifiers’, Industrial & Engineering Chemistry Research, 52(5), pp. 1819–1828. doi: 10.1021/ie301630x.
Rachmatullah, C., Aye, L. and Fuller, R. J. (2007) ‘Scenario planning for the electricity generation in Indonesia’, Energy Policy, 35(4), pp. 2352–2359. doi: 10.1016/j.enpol.2006.08.015.
Rubin, E. S., Chen, C. and Rao, A. B. (2007) ‘Cost and performance of fossil fuel power plants with CO2 capture and storage’, Energy Policy, 35(9), pp. 4444–4454. doi: 10.1016/j.enpol.2007.03.009.
Siedlecki, M. (2011) On the gasification of biomass in a steam-oxygen blown CFB gasifier with the focus on gas quality upgrading: Technology background, experiments and mathematical modeling. Delft University of Technology.
Song, G. et al. (2016) ‘Slagging characteristics of Zhundong Coal during Circulating Fluidized Bed Gasification’, Energy & Fuels, 30(5), pp. 3967–3974. doi: 10.1021/acs.energyfuels.6b00503.
Speight, J. G. (2014) ‘Gasifier Types’, Gasification of Unconventional Feedstocks. doi: 10.1016/B978-0-12-799911-1.00003-0.
Speight, J. G. (2015) ‘Gasification Reaction Kinetics for Synthetic Liquid Fuel Production’, in Gasification for Synthetic Fuel Production. Elsevier, pp. 103–117. doi: 10.1016/B978-0-85709-802-3.00005-9.
Taha, A. T., Abdel-Salam, T. M. and Vellakal, M. (2013) ‘Alternative fuels for internal combustion engines: An overview of the current research’, in Alternative Fuels Research Progress. 1st edn. International Energy and Environment Foundation, pp. 279–306.
Towler, B. F. (2014) ‘Coal and clean coal technologies’, in The Future of Energy. Elsevier, pp. 273–299. doi: 10.1016/B978-0-12-801027-3.00013-0.
Tremel, A. et al. (2013) ‘Performance of entrained flow and fluidised bed biomass gasifiers on different scales’, Energy Conversion and Management, 69, pp. 95–106. doi: 10.1016/j.enconman.2013.02.001.
Zeng, X. et al. (2014) ‘Pilot verification of a low-tar two-stage coal gasification process with a fluidized bed pyrolyzer and fixed bed gasifier’, Applied Energy, 115, pp. 9–16. doi: 10.1016/j.apenergy.2013.10.052.
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