Abstract
It is shown that it is important to take into account the variation of particle sizes due to their fragmentation in fluidized bed biomass combustion. The present state of investigations into the fragmentation process is analyzed. It is shown that primary fragmentation, a process involving cracking and disintegration of initial fuel particles into two or more parts due to thermal stresses and growth of pressure in the particles during their rapid heating at the drying and devolatization stages is the most essential issue. Factors causing the cracking of fuel particles and the nature of this process are considered. The particle fragmentation quantitative characteristics and criteria are analyzed. It is shown that the particle critical diameter is the simplest criterion for estimating the susceptibility of different fuels to fragmentation. The main factors influencing the occurrence of primary fragmentation, namely, particle size, heating rate, bed temperature, and fuel characteristics, are considered. The list of fuel’s main characteristics affecting its primary fragmentation includes the volatiles content, porosity, moisture and ash content, susceptibility of particles to swelling or shrinking, and the organic part composition. Matters concerned with predicting primary fragmentation of fuels are considered. Information about the interrelation between the main characteristics of fuels, their susceptibility to primary fragmentation, and its nature is presented. In view of biomass properties and its combustion conditions, both of the primary fragmentation mechanisms, namely due to devolatization induced stresses and thermal stresses, are supposed to take place. It can be expected that the domination of one or another mechanism will depend on the combination of particle size and heating temperature. The lines of and methods for studying the nature of biomass particles primary fragmentation and its quantitative characteristics under different conditions are outlined. The data obtained as a result of such fundamental investigations will form the basis for elaborating methods for designing furnace devices and gasifiers operating on biomass taking into account the effect of particle fragmentation on the combustion, gasification, carryover, and heating surface contamination processes.
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References
G. A. Ryabov and D. S. Litun, “The use of boiling layer technology for effective combustion and gasification of biomass,” in Renewable Power Generation. Ways of Improving the Energy Efficiency (REENFOR-2013): Proc. 1st Int. Forum, Moscow, Oct. 22–23, 2013, Ed. by O. S. Popel’ (Ob’edin. Inst. Vys. Temp. Ross. Akad. Nauk, Moscow, 2013), pp. 306–309.
G. A. Ryabov, D. S. Litun, E. A. Pitsukha, Yu. S. Teplitskii, and V. A. Borodulya, “Experience of combustion of various types of biomass in Russia and Belarus,” Elektr. Stn., No. 9. pp. 9–17 (2015).
D. S. Litun, Candidate’s Dissertation in Engineering (All-Russia Thermal Engineering Inst., Moscow, 2017).
I. T. Lau, “Char particle reaction and attrition in fluidized bed combustors: Modeling and measurement” (Canmet Energy Technology Centre, 1995).
C. J. Badenhorst, Master’s Dissertation in Chemical Engineering (North-West Univ., Potchefstroom Campus, South Africa, May 2016). http://dspace.nwu.ac.za/bitstream/handle/10394/17838/Badenhorst_CJ_2016.pdf?sequence=1&isAllowed=y.
Y. Cui and J. F. Stubington, “In-bed char combustion of Australian coals in PFBC. 3. Secondary fragmentation,” Fuel 80, 2245–2251 (2001).
M. Sreekanth, “Primary fragmentation of wood in a fluidized bed combustor — An experimental investigation,” Int. J. Innovation Sci. Res. 9, 502–510 (2014).
J. C. Van Dyk, “Development of an alternative laboratory method to determine thermal fragmentation of coal sources during pyrolysis in the gasification process,” Fuel 80, 245–249 (2001).
A. R. Kerstein and S. Niksa, “The distributed-energy chain model for rapid coal devolatilization kinetics. Part 1: Formulation,” in Proc. 20th Int. Symp. on Combustion, Ann Arbor, MI, Aug. 12–17, 1984. (Combustion Institute, Pittsburgh, PA, 1985), pp. 941–949.
R. H. Essenhigh and E. M. Suuberg, “The role of volatiles in coal combustion,” in Fundamentals of the Physical Chemistry of Pulverized Coal Combustion, Ed. by J. Lahaye, G. Prado (Martinus Nijhoff, Dordrecht, 1987), pp. 178–215.
M. Kosowska-Galachowska and A. Luckos, “An experimental investigation into the fragmentation of coal particles in a fluidized-bed combustor,” in Proc. 20th Int. Conf. on Fluidized Bed Combustion, Xi’an, May 18–20, 2009 (Springer-Verlag, Berlin, 2009), pp. 330–334.
R. Chirone, G. Greco, P. Salatino, and F. Scala, “The relevance of comminution phenomena in the fluidized bed combustion of a biomass (Robinia Psuedoacacia),” in Proc. 14th Int. Conf. on Fluidized Bed Combustion, Vancouver, May 11–14, 1997 (Am. Soc. Mech. Eng., New York, 1997), pp. 145–150.
F. Scala and R. Chirone, “Fluidized bed combustion of alternative solid fuels,” Exp. Therm. Fluid Sci. 28, 691–699 (2004).
M. Sreekanth, Ajit Kumar Kolar, and B. Leckner, “Effect of shape and size of wood on primary fragmentation in a laboratory scale fluidized bed combustor,” in Proc. 19th Int. Conf. on Fluidized Bed Combustion, Vienna, Austria, May 21–24, 2006 (Rutzky Druck, St. Poelten, Austria, 2006), Paper No.97.
R. Sudhakar, K. Srinivas Reddy, Ajit Kumar Kolar, and Bo Leckner, “Fragmentation of wood char in a laboratory scale fluidized bed combustor,” Fuel Process. Technol. 89, 1121–1134 (2008).
P. Dacombe, M. Pourkashanian, A. Williams, and L. Yap, “Combustion-induced fragmentation behaviour of isolated coal particles,” Fuel 78, 1847–1857 (1999).
M. J. Paprika, M. S. Komatina, D. V. Dakic, and S. D. Nemoda, “Prediction of coal primary fragmentation and char particle size distribution in fluidized bed,” Energy Fuels 27, 5488–5494 (2013).
O. Senneca, M. Urciuolo, and R. Chirone, “A semidetailed model of primary fragmentation of coal,” Fuel 104, 253–261 (2013).
E. G. Kelly and D. J. Spottiswood, Introduction to Mineral Processing (Wiley & Sons, New York, 1982).
S. Tian, Master’s Thesis in Chemical Engineering (University of Alberta, Edmonton, Alberta, Canada, 2011). https://era.library.ualberta.ca/items/8afe7537-d66a-4074-81b9-ce0d3622c784/view/55a12087-94fc-41a7-a045-65d2aa137426/Tian_Su_Fall%25202011.pdf.
R. Chirone and L. Massimilla, “Primary fragmentation of a coal in fluidized bed combustion,” Proc. Combust. Inst. 22, 267–277 (1988).
M. Paprika, F. Winter, M. Komatina, and D. Dakic, “Influence of FB conditions on processes within a large fuel particle during initial phases of conversion,” in Proc. 12th Int. Conf. on Fluidization — New Horizons in Fluidization Engineering, Vancouver, May 13–17, 2007 (Eng. Conf. Int., Brooklyn, NY, 2007), pp. 985–992.
H. Zhang, K. Cen, J. Yan, and M. Ni, “The fragmentation of coal particles during the coal combustion in a fluidized bed,” Fuel 81, 1835–1840 (2002).
G. H. Coetzee, Master’s Dissertation in Chemical Engineering (School of Chemical and Minerals Engineering. North-West Univ., Potchefstroom Campus, South Africa, November 2011). http://dspace.nwu.ac.za/bitstream/handle/10394/8468/Coetzee_GH.pdf;sequence=1
Z. Cui, X. Han, X. Jiang, and J. Liu, “Experiment and neural network model of primary fragmentation of oil shale in fluidized bed,” Oil Shale 26, 114–124 (2009).
D. Dakic, G. Van der Honing, and M. Valk, “Fragmentation and swelling of various coals during devolatilization in a fluid bed,” Fuel 68, 911–916 (1989).
S. E. Laubach, R. A. Marrett, J. E. Olson, and A. R. Scott, “Characteristics and origins of coal cleat: A review,” Int. J. Coal Geol. 35, 175–207 (1998).
J. R. Bunt, Doctoral Dissertation in Chemical Engineering (North-West Univ., Potchefstroom Campus, South Africa, 2006). http://citeseerx.ist.psu.edu/viewdoc/download?doi=10.1.1.459.5818&rep=rep1&type=pdf
R. Chirone, O. Senneca, D. Cumbo, and S. Russo, Relevance of Primary Fragmentation of Coal Particles During Isotherm Combustion Conditions (Ital. Sect. Combust. Inst., 2010), p. VIII–3. http://www.combustion-institute.it/proceedings/proc2008/data/papers/VIII/VIII3.pdf
G. W. Van der Merwe, Master’s Dissertation in Chemical Engineering (North-West Univ., Potchefstroom Campus, South Africa, 2010). http://dspace.nwu.ac.za/bitstream/handle/10394/11099/Van_der_Merwe_GW.pdf?sequence=1&isAllowed=y.
J. F. Stubington and T. M. Linjewile, “The effects of fragmentation on devolatilization of large coal particles,” Fuel 68, 155–160 (1989).
A. Boëlle, M. Qian, P. Jaud, R. Chirone, P. Salatino, F. Winter, X. Liu, D. Olsson, L. Amand, B. Leckner, S. Brunello, Y. Na, and G. Yue, Coal Comminution Characterization for Industrial Scale Circulating Fluidized Bed. A Research Program in the Frame of the International Energy Agency Implementing Agreement for Co-Operation in the Field of Fluidized Bed Conversion of Fuels Applied to Clean Energy Production. EDF Research & Development department. Final Joint Report. Corrected Version 30/01/022002 (Électricité de France, 2002). https://ru.scribd.com/document/245758193/lecho-de-carbon-fluidizado-pdf.
B. R. Stanmore, A. Brillard, P. Gilot, and L. Delfosse, “Fragmentation of small coal particles under fluidizedbed combustor conditions,” in Proc. 26th Int. Symp. on Combustion, Naples, Italy, July 28–Aug. 2, 1996 (Combustion Inst., Pittsburgh, PA, 1996), pp. 3269–3275. http://booksc.org/book/4393210/23e8d1.
Q. P. Campbell, J. Viljoen, M. Le Roux, and J. P. Matthews, “Micro-focus X-Ray computed tomography,” Inside Min. 7 (2), 22–25 (2014).
W. Gajewski, M. Koswoska, H. Otwinowski, and J. Szymanek, “The influence of physical properties of coal on the thermal fragmentation,” in Proc. 30th Int. Conf. of Slovak Society of Chemical Engineering, Tatranské Matliare, 26–30 May 2003 (Slovak Univ. of Technology, Bratislava, 2003).
O. Senneca, S. Russo, and R. Chirone, “Primary fragmentation of coal particles at high heating rate,” Chem. Eng. Trans. 18, 569–574 (2009).
T. Cui, Z. Zhou, Z. Dai, C. Li, G. Yu, and F. Wanf, “Primary fragmentation characteristics of coal particles during rapid pyrolysis,” Energy Fuels 29, 6231–6241 (2015). doi 10.1021/acs.energyfuels.5b01289
G. L. Van der Merwe, Master’s Dissertation in Chemical Engineering (School of Chemical and Minerals Engineering, North-West Univ., Potchefstroom Campus, South Africa, 2010). https://repository.nwu.ac.za/bitstream/handle/10394/6979/vanderMerwe_GL.pdf?sequence=2&isAllowed=y.
J. Liu, X. Jiang, L. Zhou, H. Wang, and X. Han, “Thermal stress-induced fragmentation of quartzite particles in a hot fluidized bed,” Chem. Eng. Process. 48, 507–514 (2009).
H. He, Z. Luo, and K. Cen, “Experimental research on the fragmentation of LongYan anthracite with different lithotypes in fluidized bed combustion,” in Proc. Int. Conf. on Power Engineering, Hangzhou, China, 23–27 Oct. 2007 (Zhejiang Univ. Press, Hangzhou, 2007), pp. 157–162.
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Original Russian Text © D.S. Litun, G.A. Ryabov, 2018, published in Teploenergetika.
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Litun, D.S., Ryabov, G.A. Modern State and Topical Issues of Studying Solid Fuel Particle Primary Fragmentation Processes as Applied to Biomass Combustion and Gasification in Fluidized and Dense Bed (Review). Therm. Eng. 65, 875–884 (2018). https://doi.org/10.1134/S0040601518120042
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DOI: https://doi.org/10.1134/S0040601518120042