Application of microbubbles for cleaning coal powder
Keywords:
bubble size, clean coal technology, coal, coal analysis, flotation column, microbubble generatorAbstract
It is known that Thailand has been using natural gas as its main fuel in producing electricity at the present time. A number of these reserved natural gases are likely to be dramatically decreased in the future. However, Thailand also has abundance of another fuel resource, which are the lignite coals that are considered lower quality but cheaper compared to other fuel resources. Even though lignite is not fully accepted and has bad reputation for its harmful impact on environment is being developed and used with clean coal technology in order to lower the pollution from the coal. This aims to study characteristics of bubbles produced by three different bubble generators: porous stones, ejector nozzle and pressure tank. Moreover, this study also investigates the result of coal cleaning by using the generated bubbles in order to carry the coal to the water surface. The result shows that the size of bubbles produced by porous material are appeared larger compares to the bubbles produced by the ejector nozzle combined with pressure tank are smallest. For the coal cleaning, it is found that the bubbles from the ejector nozzle combined with pressure tank can carry more coal powder to the water surface. In addition, flotation time also affects to remove sulfur and ash of the coal. The removal of sulfur content and ash content in coals, decreased with increasing flotation time. In addition, the fixed carbon and gross calorific value of the coals were increased with increasing flotation time.
References
Arakawa, T., Yamamoto, Y., & Shoji, S. (2008). Micro-bubble formation with organic membrane in a multiphase microfluidic system, Sensors and Actuators A Physical, A 143 (1), 58-63. DOI: 10.1016/j.sna.2007.06.038
Babu, K. P., Patnaik, K. S. K. R., & Sunder, R. S. (2018). Effects of operating parameters on recovery of non floatable coal by column flotation. International Journal of Applied Engineering Research 13(12), 10462-10469.
Beer, J. M. (2000). Combustion technology developments in power generation in response to environmental challenges. Progress in Energy and Combustion Science, 26(4-6), 301-327. DOI: 10.1016/S0360-1285(00)00007-1
Bhunia, K., Kundu, G., & Mukherjee, D. (2018). Performance, mixing and kinetics study in the flotation column reactor using coal, Separation Science and Technology, 53(18), 2998-3007, DOI: 10.1080/01496395.2018.1490323
Bu, X., Zhang, T., Chen, Y., Xie, G., & Peng, Y. (2017). Comparative study of conventional cell and cyclonic microbubble flotation column for upgrading a difficult-to-float Chinese coking coal using statistical evaluation. International Journal of Coal Preparation and Utilization, DOI: 10.1080/19392699.2017.1359577.
Chu, L.-B., Xing, X.-H., Yu, A.-F., Sun, X.- L., & Jurcik, B. (2008). Enhanced treatment of practical textile wastewater by microbubble ozonation. Process Safety and Environtal Protectection, 86(5), 389-393.
Franco, A., & Diaz, A. R. (2009). The future challenges for clean coal technologies: joining efficiency increase and pollutant emission control. Energy, 34(3), 348-354.
Fujikawa, S., Zhang, R., Hayama, S., & Peng, G. (2003). The control of micro-air bubble generation by a rotational porous plate. International Journal of Multiphase Flow, 29(8), 1221-1236. DOI: 10.1016/S0301-9322(03)00106-X
Fujiwara, A., Takagi, S., Watanabe, K., & Matsumoto, Y. (2003). Experimental study on the new micro-bubble generator and its application to water purification system. in: Proc. ASME/JSME 4th Joint Fluids Summer Engineering Conference, FEDSM 2003-45162, 469-473. DOI: 10.1115/FEDSM2003-45162
Han, O. H., Kim, M. K., Kim, B. G., Subasinghe, N., & Park, C. H. (2014). Fine coal beneficiation by column flotation. Fuel Processing Technology, 126, 49-59.
He, F., Gu, L., Wang, T., & Zhang, Z. (2017). The synthetic geo-ecological environmental evaluation of a coastal coal-mining city using spatiotemporal big data: A case study in Longkou, China. Journal of Cleaner Production, 142(Part 2), 854-866. https://doi.org/10.1016/j.jclepro.2016.07.011
Hirai, S., Komura, M., Saechout, V., & Sugiya, S. (2009). Development of high density micro-bubble generator for environmental technology. Electronics and Electrical Engineering, 4(92), 37-40.
Hosokawa, S., Tanaka, K., Maeda, Y., Tomiyama, A., Yamaguchi, A., & Ito, Y. (2010). Effect of entrained air bubbles generated by a pressurized dissolution method. Trans. JSME, B 76(765), 53-60.
Kaneko, Y., Maruyama, T., Takegami, K., Watanabe, T., Mitsui, H., Hanajiri, K., . . . Matsumoto, Y. (2007). Use of a microbubble agent to increase the effects of high intensity focused ultrasound on liver tissue. European radiology, 15(7), 1415-1420. DOI: 10.1007/s00330-005-2663-7
Li, B., Tao, D., Ou, Z. & Liu, J. (2003). Cyclo-microbubble column flotation of fine coal. Seperation science and technology, 38(5), 1125-1140.
Longwell, J. P., Rubint, E. S., & Wilson, J. (1995). Coal: energy for the future. Progress in Energy and Combustion Science, 21(4), 269-360. DOI: 10.1016/0360-1285(95)00007-0
Maeda, Y., Hosokawa, S., Baba, Y., Tomiyama, A., & Ito, Y. (2015). Generation mechanism of micro-bubbles in a pressurized dissolution method. Experimental Thermal and Fluid Science, 60, 201-207.
Makuta, T., Takemura, F., Hihara, E., Matsumoto, Y., & Shoji, M. (2006). Generation of micro gas bubbles of uniform diameter in an ultrasonic field. Journal of Fluid Mechanics, 548, 113-131.
Matsumoto, M., Fukunaga, T., & Onoe, K. (2010). Polymorph control of calcium carbonate by reactive crystallization using microbubble technique. Chemical Engineering Research and Design, 88(12), 1624-1630.
Ni, C., Xie, G., Liu, B., Peng, Y., Sha, J., & Xia, W. (2015). A design of an inclined froth zone in column flotation device to reduce ash content in clean coal. International Journal of Coal Preparation and Utilization, 35(6), 281-294. DOI:10.1080/19392699.2015.1019065
Oliveira, C., Rodrigues, R. T., & Rubi, J. (2009). A new technique for characterizing aerated flocs in a flocculation - microbubble flotation system. International Journal of Mineral Processing, 96, 36-44. DOI: 10.1016/j.minpro.2010.07.001
Park, C. H., Subasinghe, N., & Han, O. H. (2015). Amenability testing of fine coal beneficiation using laboratory flotation column. Materials Transactions, 56(5), 766-773. DOI: 10.2320/matertrans.M2014462
Park, J. S., & Kurata, K. (2009). Application of microbubbles to hydroponics solution promotes lettuce growth. Hort Technology, 19(1), 212-215.
Rehman, F., Medley, G. J. D., Bandulasena, H., & Zimmerman, W. B. J. (2015). Fluidic oscillator-mediated microbubble generation to provide cost effective mass transfer and mixing efficiency to the wastewater treatment plants. Environmental Research, 137, 32-39. DOI: 10.1016/j.envres.2014.11.017
Sadatomi, M., Kawahara, A., Kano, K., & Ohtomo, A. (2005). Performance of a new microbubble generator with a spherical body in a flowing water tube. Experimental Thermal and Fluid Science, 29(5), 615-623. DOI: 10.1016/j.expthermflusci.2004.08.006
Serizawa, A., Inui, T., Yashiro, T., & Kawara, Z. (2003). Laminarization of micro-bubble containing milky bubbly flow in a pipe. in: 3rd European-Japanese Two-Phase Flow Group Meeting, Certosa di Pontignano, 21-27.
Shen, M., & Wheelock, T. D. (2000). Coal agglomeration with microbubbles. Coal preparation, 21, 277-298.
Shintaku, H., Imamura, S., & Kawano, S. (2008). Microbubble formations in MEMS-fabricated rectangular channels: a high-speed observation. Experimental Thermal and Fluid Science, 32(5), 1132-1140. DOI: 10.1016/j.expthermflusci.2008.01.004
Tajima, K., Tanaka, M., Mizuno, K., Okada, N., Rokushima,K., & Watanabe, Y. (2008). Effects of bathing in micro-bubbles on recovery from moderate mental fatigue. Ergonomia IJE&HF 30(2), 137-147.
Takahashi, M., Kawamura, T., Yamamoto, Y., Ohnari, F., Himuro, S., & Shakutui, S. (2003). Effect of shrinking micro-bubble on gas hydrate formation. Journal of Physical Chemistry B, 107(10), 2171-2173. DOI: 10.1021/jp022210z
Takahashi, M. (2005). Zeta potential of micro-bubble in aqueous: electrical properties of gas–water interface. Journal of Physical Chemistry B, 109 (46), 21858-21864. DOI: 10.1021/jp0445270
Tao, D., Yu, S., Zhou, X., Honaker, R. Q., & Parekh, B. K. (2008). Picobubble column flotation of fine coal. International Journal of Coal Preparation and Utilization, 28(1), 1-14.
Terasaka, K., Hirabayashi, A., Nishino, T., Fujioka, S., & Kobayashi, D. (2011). Development of microbubble aerator for waste water treatment using aerobic activated sludge. Chemical Engineering Science, 66(14), 3172-3179. https://doi.org/10.1016/j.ces.2011.02.043
Thiemann, A., Nowak, T., Mettin, R., Holsteyns, F., & Lippert, A. (2011). Characterization of an acoustic cavitation bubble structure at 230 kHz, Ultrasonics sonochemistry, 18(2), 595-600. DOI: 10.1016/j.ultsonch.2010.10.004
Xu, J. H., Li, S. W., Chen, G. G., & Luo, G. S. (2006). Formation of monodisperse microbubbles in a microfluidic device. American Institute of Chemical Engineers AIChE J., 52(6), 2254-2259. https://doi.org/10.1002/aic.10824
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