PYROLYSIS CHARACTERISTICS AND KINETIC ANALYSIS OF COMMON PLASTICS
-
摘要: 研究塑料废弃物的热解特性有助于实现其清洁高效转化利用。借助热重技术总结对比了高密度聚乙烯、低密度聚乙烯和聚丙烯的不同升温速率(10,20,30,40,50℃/min)热解及不同催化剂(HZSM-5、Hβ和HUSY)催化热解的特性及规律。升温速率的增长使反应出现热迟滞现象,催化剂的加入对样品热解速率提高的效果也不尽相同。为了提供更有力的理论支持,运用3种动力学分析方法Coats-Redfern (CR)、Flynn-Wall-Ozawa (FWO)和分布式活化能法(DAEM),对样品在不同条件下的动力学参数进行计算和分析。CR模型验证了各热解反应符合一级化学反应模型并发现催化剂可以大幅降低反应活化能;FWO法和DAEM得到的表观活化能数值接近。DAEM模型显示活化能在转化率α增长的过程中先上升再逐步下降,在α=40%~50%时活化能最高,且包含动力学补偿效应。Abstract: The study on pyrolysis characteristics of plastic waste is in favor of achieving its clean and efficient conversion and utilization. The catalytic pyrolysis characteristics of high-density polyethylene(HDPE), low-density polyethylene(LDPE), and polypropylene(PP), with three different catalysts of HZSM-5,Hβ and HUSY, were investigated by the thermogravimetric experiments at different heating rates of 10, 20, 30,40,50 ℃/min. The increase of heating rate caused thermal hysteresis, and the different types of catalysts had different effects on the improvement of pyrolysis rates of the HDPE, LDPE, and PP. In order to provide theoretical support, three kinetic modeling analysis methods, including Coats-Redfern(CR), Flynn-Wall-Ozawa(FWO), and distributed activation energy model(DAEM), were used to calculate the kinetic parameters of HDPE, LDPE, and PP pyrolysis under different conditions. CR method verified that each pyrolysis reaction was following the first-order reaction model and found that the catalysts could significantly reduce the activation energy of the reaction. The calculated activation energy by two iso-conversion rate methods, including the FWO method and DAEM, was similar to each other. The DAEM model, including the kinetic compensation effect, showed that the activation energy increased and then decreased as the conversion rate(α) increases, and reached the highest at α=40%~50%.
-
Key words:
- plastic /
- pyrolysis /
- catalytic /
- kinetic analysis
-
[1] MA Z,JIANG W,YANG S,et al.China plastics processing industry(2019)[J].China Plastics,2020,34(5):102-106. [2] 顾菁,程磊磊,王亚琢,等.聚乙烯高压热解及其反应机理研究[J].燃料化学学报,2021,49(3):395-406. [3] SAHA B,REDDY P K,CHOWLU A C K,et al.Model-free kinetics analysis of nanocrystalline HZSM-5 catalyzed pyrolysis of polypropylene (PP)[J].Thermochimica Acta,2008,468:94-100. [4] 黄明,朱亮,丁紫霞,等.生物质三组分与低密度聚乙烯共催化热解制取轻质芳烃的协同作用机理[J].化工学报,2022,73(2):699-711,475. [5] 李丽霞,任金忠,孙瑞祥,等.废弃PP、PE、PS和PVC塑料制品的热降解动力学研究[J].山东化工,2022,51(4):28-30,33. [6] KHEDRI S,ELYASI S,Kinetic analysis for thermal cracking of HDPE:a new isoconversional approach[J].Polymer Degradation and Stability,2016,129:306-318. [7] SAAD J M,WILLIAMS P T,ZHANG Y,et al.Comparison of waste plastics pyrolysis under nitrogen and carbon dioxide atmospheres:a thermogravimetric and kinetic study[J].Journal of Analytical and Applied Pyrolysis,2021,156:105-135. [8] ALAM M,BHAVANAM A,JANA A,et al.Co-pyrolysis of bamboo sawdust and plastic:synergistic effects and kinetics[J].Renewable Energy,2020,149:1133-1145. [9] 郭慧敏,李翔宇,王海彦,等.纤维素和聚丙烯共催化热解热重分析及动力学研究[J].太阳能学报,2017,38:2705-2711. [10] ZHANG X,LEI H,ZHU L,ZHU X,et al.Thermal behavior and kinetic study for catalytic co-pyrolysis of biomass with plastics[J].Bioresource Technology,2016,220:233-238. [11] 刘雪梅,蒋剑春,孙康,等.椰壳热解动力学分析[J].安徽农业科学,2012,40(27):13540-13542. [12] SARBISHEI S,TAFAGHODI KHAJAVI L.Kinetic analysis on nickel laterite ore calcination using model-free and model-fitting methods[J].Minerals Engineering,2019,136:129-139. [13] 朱琦.典型塑料的催化热解动力学研究及积碳特性分析[D].天津:河北工业大学:2020. [14] MIAN I,LI X,JIAN Y,et al.Kinetic study of biomass pellet pyrolysis by using distributed activation energy model and Coats Redfern methods and their comparison[J].Bioresource Technology,2019,294:122099. [15] 杨景标,张彦文,蔡宁生.煤热解动力学的单一反应模型和分布活化能模型比较[J].热能动力工程,2010,25:301-305,358. [16] RAZA M,ABU-JDAYIL B,AL-MARZOUQI A H,et al.Kinetic and thermodynamic analyses of date palm surface fibers pyrolysis using Coats-Redfern method[J].Renewable Energy,2022,183:67-77. [17] 孙云娟,蒋剑春,赵淑蘅,等.稻壳与褐煤共热解动力学研究[J].太阳能学报,2016,37(11):2747-2753. [18] DAS P,TIWARI P,Valorization of packaging plastic waste by slow pyrolysis[J].Resources,Conservation and Recycling,2018,128:69-77. [19] WU L,JIANG X,LV G,et al.Interactive effect of the sorted components of solid recovered fuel manufactured from municipal solid waste by thermogravimetric and kinetic analysis[J].Waste Management,2020,102:270-280. [20] CONESA J A,MARCILLA A,CABALLERO J A,et al.Comments on the validity and utility of the different methods for kinetic analysis of thermogravimetric data[J].Journal of Analytical and Applied Pyrolysis,2001,58-59:617-633. [21] LI L,WANG G,WANG S,QIN S.Thermogravimetric and kinetic analysis of energy crop Jerusalem artichoke using the distributed activation energy model[J].Journal of Thermal Analysis & Calorimetry,2013,114:1183-1189. [22] ZHAO J,HUANG X,XU T.Combustion mechanism of asphalt binder with TG-MS technique based on components separation[J].Construction and Building Materials,2015,80:125-131. [23] 李成俊,姜皓,赵炬明.锡林浩特褐煤热解特性热重分析与DAEM模型分析[J].节能技术,2015,33(1):69-71. [24] CARLOS H,BENEDETTA C,STEFANO S,et al.Comparison of global models of sub-bituminous coal devolatilization by means of thermogravimetric analysis[J].Journal of Thermal Analysis & Calorimetry,2014,117:507-516. [25] BALLICE L,REIMERT R.Classification of volatile products from the temperature-programmed pyrolysis of polypropylene (PP),atactic-polypropylene (APP) and thermogravimetrically derived kinetics of pyrolysis[J].Chemical Engineering and Processing:Process Intensification,2002,41:289-296. [26] ELORDI G,OLAZAR M,LOPEZ G,et al.Catalytic pyrolysis of HDPE in continuous mode over zeolite catalysts in a conical spouted bed reactor[J].Journal of Analytical and Applied Pyrolysis,2009,85:345-351. [27] 孙艺蕾,马跃,李术元,等.聚烯烃塑料的热解和催化热解研究进展[J].化工进展,2021,40(5):2784-2801. [28] KIM J R,KIM Y A,YOON J H,et al.Catalytic degradation of polypropylene:effect of dealumination of clinoptilolite catalyst[J].Polymer Degradation and Stability,2002,75:287-294. [29] MARCILLA A,GÓMEZ-SIURANA A,VALDÉS F.Catalytic pyrolysis of LDPE over H-beta and HZSM-5 zeolites in dynamic conditions:study of the evolution of the process[J].Journal of Analytical and Applied Pyrolysis,2007,79:433-442. [30] 闫国荀.聚烯烃热裂解及裂解产物作低碳烯烃生产原料的研究[D].青岛:青岛科技大学,2015. [31] XU F,WANG B,YANG D,et al.Thermal degradation of typical plastics under high heating rate conditions by TG-FTIR:pyrolysis behaviors and kinetic analysis[J].Energy Conversion and Management,2018,171:1106-1115. [32] ABOULKAS A,EL HARFI K,EL BOUADILI A.Thermal degradation behaviors of polyethylene and polypropylene.Part Ⅰ:pyrolysis kinetics and mechanisms[J].Energy Conversion and Management,2010,51:1363-1369. [33] ZHONG S,ZHANG B,LIU C,et al.Mechanism of synergistic effects and kinetics analysis in catalytic co-pyrolysis of water hyacinth and HDPE[J].Energy Conversion and Management,2021,228:113717. [34] 尹凤福,庄虔晓,常天浩等.外卖塑料包装热解动力学研究:基于无模型和模型拟合法[J].中国环境科学,2021,41(4):1756-1764. [35] XU S,CAO B,UZOEJINWA B B,et al.Synergistic effects of catalytic co-pyrolysis of macroalgae with waste plastics[J].Process Safety and Environmental Protection,2020,137:34-48. [36] NAVARRO M V,LÓPEZ J M,VESES A,et al.Kinetic study for the co-pyrolysis of lignocellulosic biomass and plastics using the distributed activation energy model[J].Energy,2018:731-742. [37] 黄金保,伍丹,童红等.聚乙烯热裂解行为的分子动力学模拟[J].材料导报,2013,27(S1):130-132. [38] 邹文樵.化学动力学中的补偿效应[J].大学化学,1997,(2):48-50. [39] WANG W,LUO G,ZHAO Y,et al.Kinetic and thermodynamic analyses of co-pyrolysis of pine wood and polyethylene plastic based on Fraser-Suzuki deconvolution procedure[J].Fuel,2022,322:124200. [40] 李宇宇.落叶松热解动力学分析误差研究[D].北京:北京林业大学,2012.
点击查看大图
计量
- 文章访问数: 436
- HTML全文浏览量: 32
- PDF下载量: 15
- 被引次数: 0