Abstract: A novel central hole-expansion phenomenon is identified, in which the cation-exchange resin is pyrolyzed in a mixed atmosphere of nitrogen and oxygen at 400‍–‍500°C. In this reaction, the reaction path is predictable and always starts from the center of the resin particle to form a central hole, then continues and expands around the hole, finally forming a uniformly distributed hole group; the particle surface remains intact. Analysis shows that this formation mode is due to the different reaction paths of sulfonic groups between the surface and interior of the particle, caused by the temperature difference. On the surface, transformation reactions happen at high temperatures (410‍–‍500°C) to form stable organic sulfur structures, while decomposition occurs inside the particle at a relatively low temperature (<410 °C) and promotes complete pyrolysis of the copolymer matrix to form holes.

阳离子交换树脂颗粒热解过程中的孔增长现象

[1]AmutioM, LopezG, AguadoR, et al., 2012. Kinetic study of lignocellulosic biomass oxidative pyrolysis. Fuel, 95:‍305-311.

[2]AsfawHD, YounesiR, ValvoM, et al., 2016. Boosting the thermal stability of emulsion-templated polymers via sulfonation: an efficient synthetic route to hierarchically porous carbon foams. ChemistrySelect, 1(4):784-792.

[3]BachQV, TrinhTN, TranKQ, et al., 2017. Pyrolysis characteristics and kinetics of biomass torrefied in various atmospheres. Energy Conversion and Management, 141:72-78.

[4]BavaYB, GeronésM, GiovanettiLJ, et al., 2019. Speciation of sulphur in asphaltenes and resins from Argentinian petroleum by using XANES spectroscopy. Fuel, 256:115952.

[5]ChenT, KuX, LinJZ, et al., 2018. New pyrolysis model for biomass particles in a thermally thick regime. Energy & Fuels, 32(9):9399-9414.

[6]ChenYJ, JingL, LiXL, et al., 2006. Suppressed anion chromatography using mixed zwitter-ionic and carbonate eluents. Journal of Chromatography A, 1118(1):3-11.

[7]ChunUK, ChoiK, YangKH, et al., 1998. Waste minimization pretreatment via pyrolysis and oxidative pyroylsis of organic ion exchange resin. Waste Management, 18(3):‍183-196.

[8]GómezMA, PorteiroJ, PatiñoD, et al., 2015. Fast-solving thermally thick model of biomass particles embedded in a CFD code for the simulation of fixed-bed burners. Energy Conversion and Management, 105:30-44.

[9]HommaS, OgataS, KogaJ, et al., 2005. Gas‍–‍solid reaction model for a shrinking spherical particle with unreacted shrinking core. Chemical Engineering Science, 60(18):4971-4980.

[10]HouJL, MaY, LiSY, et al., 2018. Transformation of sulfur and nitrogen during Shenmu coal pyrolysis. Fuel, 231:134-144.

[11]HuHY, FangY, LiuH, et al., 2014. The fate of sulfur during rapid pyrolysis of scrap tires. Chemosphere, 97:‍102-107.

[12]JuangRS, LeeTS, 2002. Oxidative pyrolysis of organic ion exchange resins in the presence of metal oxide catalysts. Journal of Hazardous Materials, 92(3):301-314.

[13]MatsudaM, FunabashiK, YusaH, et al., 1987. Influence of functional sulfonic acid group on pyrolysis characteristics for cation exchange resin. Journal of Nuclear Science and Technology, 24(2):124-128.

[14]OluotiKO, RichardsT, DoddapaneniTRK, et al., 2014. Evaluation of the pyrolysis and gasification kinetics of tropical wood biomass. BioResources, 9(2):2179-2190.

[15]PetersenEE, 1957. Reaction of porous solids. AIChE Journal, 3(4):443-448.

[16]RamachandranPA, DoraiswamyLK, 1982. Modeling of noncatalytic gas-solid reactions. AIChE Journal, 28(6):‍881-900.

[17]RenQQ, ZhaoCS, 2012. NO_x and N₂O precursors from biomass pyrolysis: nitrogen transformation from amino acid. Environmental Science & Technology, 46(7):‍4236-4240.

[18]SadhukhanAK, GuptaP, SahaRK, 2009. Modelling of pyrolysis of large wood particles. Bioresource Technology, 100(12):3134-3139.

[19]SadhukhanAK, GuptaP, SahaRK, 2010. Modelling of combustion characteristics of high ash coal char particles at high pressure: shrinking reactive core model. Fuel, 89(1):162-169.

[20]SafariV, ArzpeymaG, RashchiF, et al., 2009. A shrinking particle—shrinking core model for leaching of a zinc ore containing silica. International Journal of Mineral Processing, 93(1):79-83.

[21]ShenDK, GuS, JinBS, et al., 2011. Thermal degradation mechanisms of wood under inert and oxidative environments using DAEM methods. Bioresource Technology, 102(2):2047-2052.

[22]SingarePU, LokhandeRS, MadyalRS, 2010. Thermal degradation studies of polystyrene sulfonic and polyacrylic carboxylic cationites. Russian Journal of General Chemistry, 80(3):527-532.

[23]SzekelyJ, PropsterM, 1975. A structural model for gas solid reactions with a moving boundary-VI: the effect of grain size distribution on the conversion of porous solids. Chemical Engineering Science, 30(9):1049-1055.

[24]TrubetskayaA, LeahyJJ, YazhenskikhE, et al., 2019. Characterization of woodstove briquettes from torrefied biomass and coal. Energy, 171:853-865.

[25]UhdeG, HoffmannU, 1997. Noncatalytic gas-solid reactions: modelling of simultaneous reaction and formation of surface with a nonisothermal crackling core model. Chemical Engineering Science, 52(6):1045-1054.

[26]VyazovkinS, BurnhamAK, CriadoJM, et al., 2011. ICTAC kinetics committee recommendations for performing kinetic computations on thermal analysis data. Thermochimica Acta, 520(1-2):1-19.

[27]WenCY, 1968. Noncatalytic heterogeneous solid-fluid reaction models. Industrial & Engineering Chemistry, 60(9):34-54.

[28]YagiS, KuniiD, 1955. Studies on fluidized-solids reactors for particles with decreasing diameters. Chemical Engineering, 19(10):500-506 (in Janpanese).

[29]YangHC, LeeMW, HwangHS, et al., 2014. Study on thermal decomposition and oxidation kinetics of cation exchange resins using non-isothermal TG analysis. Journal of Thermal Analysis and Calorimetry, 118(2):‍1073-1083.

[30]YangHC, LeeSY, ChoiYC, et al., 2017. Thermokinetic analysis of spent ion-exchange resins for the optimization of carbonization reactor condition. Journal of Thermal Analysis and Calorimetry, 127(1):587-595.

[31]YaoX, YuQB, HanZR, et al., 2018. Kinetic and experimental characterizations of biomass pyrolysis in granulated blast furnace slag. International Journal of Hydrogen Energy, 43(19):9246-9253.

[32]YoshiokaT, MotokiT, OkuwakiA, 2001. Kinetics of hydrolysis of poly (ethylene terephthalate) powder in sulfuric acid by a modified shrinking-core model. Industrial & Engineering Chemistry Research, 40(1):75-79.