Aerobic pyrolysis kinetic and product characteristics of waste crystalline silicon photovo ltaic modules’ EVA

doi:10.11949/0438-1157.20240306

Abstract

Abstract:

Resource treatment and recycling of waste crystalline silicon photovoltaic modules is urgent, and the key lies in the processing of ethylene vinyl acetate copolymer (EVA) films. This paper focuses on EVA treatment, proposing an aerobic pyrolysis method, and delves into the characteristics of aerobic pyrolysis mass loss, kinetics, and product analysis. The research findings indicate that with increasing oxygen concentration, the maximum mass loss rate increases from 1.8%(mass)/s to 3.0%(mass)/s, indicating more rapid and abundant thermal decomposition of EVA at lower temperatures. As the oxygen concentration rises, the overall aerobic pyrolysis activation energy shows a decreasing trend. This is attributed to the presence of oxygen promoting oxidation reactions, accelerating the aerobic pyrolysis process. With the increase in final pyrolysis temperature, the yields of coke and oil decrease, while gas yield increases. At 2% oxygen concentration, the increase in final pyrolysis temperature favors the enrichment of CH₄ and C₂H₆ substances in the gas phase, facilitates the conversion of carboxylic substances in oil to alkanes, alkenes, and alcohols, leading to the gradual transition of coke from amorphous structure to aromatization and graphitization.

Key words: photovoltaic modules, ethylene vinyl acetate, aerobic pyrolysis, oxygen, mass loss, kinetics, products

摘要：

资源化处理回收废旧晶体硅光伏组件迫在眉睫，而其关键在于乙烯-醋酸乙烯共聚物（EVA）薄膜的处理。面向EVA处理提出了有氧热解方法，展开有氧热解失重特性、动力学及产物特性分析，结果表明：随着氧气浓度的增加，最大失重速率从1.8%（质量分数）/s增加到3.0%（质量分数）/s，EVA在较低温度下热分解更多且速率更快，整体有氧热解活化能呈现出下降的趋势。这是由于氧气的存在促进了氧化反应，加速了有氧热解过程。随着热解终温的升高，焦与油产率呈下降趋势，气产率则随之增加。在2%氧气浓度下，热解终温的提高有利于CH₄、C₂H₆物质富集，有利于油中羧类物质转化为烷烃、烯烃及醇类，使得焦逐渐由非晶质结构朝芳香化与石墨化转变。

关键词: 光伏组件, EVA, 有氧热解, 氧气, 失重, 动力学, 产物

CLC Number:

X 773

Yong DING, Wenjian LI, Zhaoyu CHEN, Lihui CAO, Xuanming LIU, Qiangqiang REN, Song HU, Jun XIANG. Aerobic pyrolysis kinetic and product characteristics of waste crystalline silicon photovo ltaic modules’ EVA[J]. CIESC Journal, 2024, 75(9): 3310-3319.

丁湧, 李文建, 陈昭宇, 曹立辉, 刘轩铭, 任强强, 胡松, 向军. 废旧晶体硅光伏组件EVA有氧热解动力学与产物特性[J]. 化工学报, 2024, 75(9): 3310-3319.

Figures/Tables 11

Fig.1 Fragments containing EVA (a) and EVA powder after crushing and sieving (b)

Table 1 Industrial and elemental analysis of EVA （mass fraction， as received basis）

工业分析/%				元素分析/%					高位发热量/(MJ/kg)
M	V	FC	A	C	H	N	S	O^①	高位发热量/(MJ/kg)
0.22	97.61	2.12	0.04	77.83	10.51	2.14	0.01	9.24	14.15

Fig.2 Aerobic pyrolysis mass loss and mass loss rate curves of EVA under different heating rates and oxygen concentrations

Fig.3 Fitting curves of EVA aerobic pyrolysis kinetic under oxygen free condition

Table 2 Apparent activation energy and average activation energy of EVA aerobic pyrolysis at different oxygen concentrations

氧气浓度	E/(kJ/mol)									$\bar{E}$ /(kJ/mol)
氧气浓度	α=0.1	α=0.2	α=0.3	α=0.4	α=0.5	α=0.6	α=0.7	α=0.8	α=0.9	$\bar{E}$ /(kJ/mol)
0	46.47	50.06	80.30	80.00	85.96	89.53	91.08	92.72	91.10	78.58
2%	45.14	47.64	85.07	89.91	82.78	80.72	80.06	79.63	79.43	74.49
5%	39.84	45.78	44.36	104.57	91.01	86.50	84.50	83.35	82.66	73.62
10%	30.54	42.04	38.01	110.12	85.07	77.74	74.58	73.78	78.54	67.82

Table 2 Apparent activation energy and average activation energy of EVA aerobic pyrolysis at different oxygen concentrations

氧气浓度	E/(kJ/mol)									$\bar{E}$ /(kJ/mol)
氧气浓度	α=0.1	α=0.2	α=0.3	α=0.4	α=0.5	α=0.6	α=0.7	α=0.8	α=0.9	$\bar{E}$ /(kJ/mol)
0	46.47	50.06	80.30	80.00	85.96	89.53	91.08	92.72	91.10	78.58
2%	45.14	47.64	85.07	89.91	82.78	80.72	80.06	79.63	79.43	74.49
5%	39.84	45.78	44.36	104.57	91.01	86.50	84.50	83.35	82.66	73.62
10%	30.54	42.04	38.01	110.12	85.07	77.74	74.58	73.78	78.54	67.82

Fig.4 Distribution of apparent activation energy with conversion rate during pyrolysis process of EVA

Fig.5 Yield of aerobic pyrolysis products from EVA at different pyrolysis temperatures

Fig.6 Composition and yield of aerobic pyrolysis gases from EVA at different pyrolysis temperatures

Fig.7 Composition and yield of aerobic pyrolysis oil from EVA at different pyrolysis temperatures

Fig.8 FTIR spectra of aerobic pyrolysis char from EVA at different pyrolysis temperatures

Fig.9 Raman spectra of aerobic pyrolysis char from EVA at different pyrolysis temperatures

References 33

1	Lycourghiotis S. Trends in renewable energy: an overview[J]. Global NEST: the International Journal, 2022, 24(3): 505-525.
2	Ahmad L, Khordehgah N, Malinauskaite J, et al. Recent advances and applications of solar photovoltaics and thermal technologies[J]. Energy, 2020, 207: 118254.
3	水电水利规划设计总院. 中国可再生能源发展报告2022[R]. 北京:水电水利规划设计总院, 2023.
	Hydroelectric and Water Resources Planning and Design Institute. Development Report on Renewable Energy in China 2022 [R]. Beijing: Hydroelectric and Water Resources Planning and Design Institute, 2023.
4	李淳伟, 胡露, 樊阳波, 等. 光伏组件回收利用现状研究及标准探讨[J]. 中国标准化, 2020, (S1): 163-168.
	Li C W, Hu L, Fan Y B, et al. Research on the current situation and standard of photovoltaic module recycling[J]. China Standardization, 2020, (S1): 163-168.
5	Tammaro M, Salluzzo A, Rimauro J, et al. Experimental investigation to evaluate the potential environmental hazards of photovoltaic panels[J]. Journal of Hazardous Materials, 2016, 306: 395-405.
6	Rong D, Chang N L, Ouyang Z, et al. A techno-economic review of silicon photovoltaic module recycling[J]. Renewable and Sustainable Energy Reviews, 2019, 109: 532-550.
7	吴智朋, 高德东, 王珊, 等. 废旧晶体硅光伏组件回收技术研究进展[J]. 机械工程学报,2023,59(7):307-329.
	Wu Z P, Gao D D, Wang S, et al. Research progress on recycling technology of waste crystalline silicon photovoltaic modules[J]. Journal of Mechanical Engineering, 2023, 59(7): 307-329.
8	孔慧玲, 顾卫华, 彭圣娟, 等. 废旧光伏组件回收及高值化利用研究进展[J]. 有色金属 (冶炼部分), 2023, (9): 22-29.
	Kong H L, Gu W H, Peng S J, et al. Research progress on recycling and high value utilization of waste photovoltaic modules[J]. Nonferrous Metals (Extractive Metallurgy), 2023, (9): 22-29.
9	Farrell C C, Osman A I, Doherty R, et al. Technical challenges and opportunities in realising a circular economy for waste photovoltaic modules[J]. Renewable and Sustainable Energy Reviews, 2020, 128: 109911.
10	Wang X P, Tian X Y, Chen X D, et al. A review of end-of-life crystalline silicon solar photovoltaic panel recycling technology[J]. Solar Energy Materials and Solar Cells, 2022, 248: 111976.
11	Pagnanelli F, Moscardini E, Altimari P, et al. Solvent versus thermal treatment for glass recovery from end of life photovoltaic panels: environmental and economic assessment[J]. Journal of Environmental Management, 2019, 248: 109313.
12	Tao M, Click N, Ricci L. Commentary on technoeconomic analysis of high-value, crystalline silicon photovoltaic module recycling processes[solar energy materials and solar cells 238 (2022) 111592][J]. Solar Energy Materials and Solar Cells, 2022, 239: 111677.
13	El abdellaoui F, Roethlisberger R P, Ez-Zahraouy H. Oxidative pyrolysis of pellets from lignocellulosic anaerobic digestion residues and wood chips for biochar and syngas production[J]. Fuel, 2023, 350: 128824.
14	Fu W, Bai X W, Tursun Y, et al. Oxidative pyrolysis of plywood waste: effect of oxygen concentration and other parameters on product yield and composition[J]. Journal of Analytical and Applied Pyrolysis, 2023, 173: 106068.
15	Huang R, Ren Q Q, Zhang J L, et al. Adjusting effects of pyrolytic volatiles interaction in char to upgrade oil by swelling waste nylon-tire[J]. Waste Management, 2023, 169: 374-381.
16	Wang F C Y, The microstructure exploration of thermoplastic copolymers by pyrolysis-gas chromatography[J]. Journal of Analytical and Applied Pyrolysis, 2004, 71(1): 83-106.
17	章蕾, 宋孝辉, 张建庭, 等. 氨甲环酸异构化过程的反应动力学研究[J]. 化工学报,2023, 74(10): 4173-4181.
	Zhang L, Song X H, Zhang J T, et al. Reaction kinetics study of tranexamic acid isomerization process[J]. CIESC Journal, 2023, 74(10): 4173-4181.
18	Vyazovkin S, Dollimore D. Linear and nonlinear procedures in isoconversional computations of the activation energy of nonisothermal reactions in solids[J]. Journal of Chemical Information and Computer Sciences, 1996, 36(1): 42-45.
19	张玉明, 纪德馨, 朱翰文, 等. 微型流化床中萘裂解生成小分子气体的反应动力学研究[J]. 化工学报, 2021, 72(5): 2604-2615.
	Zhang Y M, Ji D X, Zhu H W, et al. Reaction kinetics of naphthalene cracking into small molecule gas in a micro fluidized bed[J]. CIESC Journal, 2021, 72(5): 2604-2615.
20	赵旭, 卜昌盛, 王昕晔, 等. 铁基载氧体辅助无烟煤焦富氧燃烧动力学分析[J]. 化工学报, 2022, 73(1): 384-392.
	Zhao X, Bu C S, Wang X Y, et al. Kinetics investigation on iron-based oxygen carrier aided oxy-fuel combustion of anthracite char[J]. CIESC Journal, 2022, 73(1): 384-392.
21	徐智, 郭朝晖, 徐锐, 等. 控氧热解过程中污染稻草生物炭的组分特性及其重金属累积特征[J]. 环境科学, 2023, 44(2): 1051-1062.
	Xu Z, Guo Z H, Xu R, et al. Component properties and heavy metal accumulation characteristics of contaminated rice straw biochar during oxygen-controlled pyrolysis[J]. Environmental Science, 2023, 44(2): 1051-1062.
22	Cindro N, Car Ž, Petrović Peroković V, et al. Synthesis of aromatic polynitroso compounds: towards functional azodioxy-linked porous polymers[J]. Heliyon, 2023, 9(11): e21781.
23	Maurya M R, Kumar A, Costa Pessoa J. Vanadium complexes immobilized on solid supports and their use as catalysts for oxidation and functionalization of alkanes and alkenes[J]. Coordination Chemistry Reviews, 2011, 255(19/20): 2315-2344.
24	Fang S W, Yu Z S, Ma X Q, et al. Co-pyrolysis characters between combustible solid waste and paper mill sludge by TG-FTIR and Py-GC/MS[J]. Energy Conversion and Management, 2017, 144: 114-122.
25	徐芳, 刘辉, 王擎, 等. 霍林河褐煤化学结构特性的¹³C NMR与FTIR对比分析[J]. 化工学报, 2017, 68(11): 4272-4278.
	Xu F, Liu H, Wang Q, et al. Comparison of Huolinhe lignite structural features by using ¹³C NMR & FTIR techniques [J]. CIESC Journal, 2017, 68(11): 4272-4278.
26	Yadav K, Shah D, Pal S L, et al. Quantitative analysis of functional groups in different metamorphic grade Indian coals using FTIR technique[J]. Materials Today: Proceedings, 2023.
27	Lin Y, Liao Y F, Yu Z S, et al. A study on co-pyrolysis of bagasse and sewage sludge using TG-FTIR and Py-GC/MS[J]. Energy Conversion and Management, 2017, 151: 190-198.
28	Lei Z, Yang D, Zhang Y H, et al. Constructions of coal and char molecular models based on the molecular simulation technology[J]. Journal of Fuel Chemistry and Technology, 2017, 45(7): 769-779.
29	Bu R P, Liu G R, Zhong K, et al. Relationship between the molecular structure and stacking mode: characteristics of the D₂ _h and D₃ _h molecules in planar layer-stacked crystals[J]. Crystal Growth & Design, 2021, 21(12): 6847-6861.
30	蔚翠, 何泽召, 刘庆彬, 等. 蓝宝石衬底上PECVD生长石墨烯及其气敏传感器[J]. 化工学报, 2017, 68(11): 4423-4427.
	Yu C, He Z Z, Liu Q B, et al. PECVD growth of graphene on sapphire substrate and its gas sensor[J]. CIESC Journal, 2017, 68(11): 4423-4427.
31	李津蓉, 戴连奎, 阮华. 基于谱峰分解的拉曼光谱定量分析方法[J]. 化工学报, 2012, 63(7): 2128-2135.
	Li J R, Dai L K, Ruan H. Raman spectral quantitative analysis based on peaks-decomposition[J]. CIESC Journal, 2012, 63(7): 2128-2135.
32	董莉, 周潇云, 刘景洋, 等. 废光伏组件乙烯-醋酸乙烯酯共聚物热解研究[J]. 环境污染与防治, 2020, 42(10): 1211-1215.
	Dong L, Zhou X Y, Liu J Y, et al. Study on thermal decomposition of ethylene-vinyl acetate copolymer in waste photovoltaic modules[J]. Environmental Pollution & Control, 2020, 42(10): 1211-1215.
33	Preeda P, Ganapathi Raman R, Sakthivel P. Structural, FTIR, FT-Raman, optical and nonlinear optical properties of organic nonlinear optical crystal–3,5-diisopropyl-2-hydroxybenzoic acid[J]. Inorganic Chemistry Communications, 2022, 146: 110120.

[1]	Hongbiao XU, Liang YANG, Zidong LI, Daoping LIU. Kinetics of methane hydrate formation in saline droplets/copper foam composite system [J]. CIESC Journal, 2024, 75(9): 3287-3296.
[2]	Yachao LIU, Xiaojie TAN, Xudong LI, Rui WANG, Hui WANG, Xuan HAN, Qingshan ZHAO. Synthesis of efficient cobalt carbonate nanosheets based on DES for oxygen evolution reaction [J]. CIESC Journal, 2024, 75(9): 3320-3328.
[3]	Jialei CAO, Liyan SUN, Dewang ZENG, Fan YIN, Zixiang GAO, Rui XIAO. Numerical simulation of chemical looping hydrogen generation with dual fluidized bed reactors [J]. CIESC Journal, 2024, 75(8): 2865-2874.
[4]	Li LUO, Wenyao CHEN, Jing ZHANG, Gang QIAN, Xinggui ZHOU, Xuezhi DUAN. Alumina structure and surface property regulation for catalyzing methanol dehydration to dimethyl ether [J]. CIESC Journal, 2024, 75(7): 2522-2532.
[5]	Xusheng LIU, Zeyang LI, Yusen YANG, Min WEI. Research progress on electrocatalytic carbon dioxide reduction to gaseous products [J]. CIESC Journal, 2024, 75(7): 2385-2408.
[6]	Wenya WANG, Wei ZHANG, Xiaoling LOU, Ruofei ZHONG, Bingbing CHEN, Junxian YUN. Multi-microtubes formation and simulation of nanocellulose-embedded cryogel microspheres [J]. CIESC Journal, 2024, 75(5): 2060-2071.
[7]	Mingze SUN, Helai HUANG, Zhiqiang NIU. Pt-based oxygen reduction reaction catalysts: from single crystal electrode to nanostructured extended surface [J]. CIESC Journal, 2024, 75(4): 1256-1269.
[8]	Xiao XUE, Minjing SHANG, Yuanhai SU. Advances on continuous-flow synthesis of drugs in microreactors [J]. CIESC Journal, 2024, 75(4): 1439-1454.
[9]	Yiwei FAN, Wei LIU, Yingying LI, Peixia WANG, Jisong ZHANG. Research progress on catalytic dehydrogenation of dodecahydro-N-ethylcarbazole as liquid organic hydrogen carrier [J]. CIESC Journal, 2024, 75(4): 1198-1208.
[10]	Xudong JIA, Bolong YANG, Qian CHENG, Xueli LI, Zhonghua XIANG. Preparation of high-efficiency iron-cobalt bimetallic site oxygen reduction electrocatalysts by step-by-step metal loading method [J]. CIESC Journal, 2024, 75(4): 1578-1593.
[11]	Anran XU, Kai LIU, Na WANG, Zhenyu ZHAO, Hong LI, Xin GAO. Strong wave-absorbing catalyst cooperates with microwave energy to enhance fructose dehydration to produce 5-hydroxymethylfurfural [J]. CIESC Journal, 2024, 75(4): 1565-1577.
[12]	Jiaqi WANG, Haoqi WEI, Ajing GOU, Jiaxing LIU, Xinlin ZHOU, Kun GE. Study on the formation mechanism of CO₂ hydrate under the action of nanoparticles [J]. CIESC Journal, 2024, 75(3): 956-966.
[13]	Pei WANG, Ruiming DUAN, Guangru ZHANG, Wanqin JIN. Modeling and simulation analysis of solar driven membrane separation biomethane hydrogen production process [J]. CIESC Journal, 2024, 75(3): 967-973.
[14]	Zhaoxiang ZHANG, Maokun CAI, Zhiying REN, Xiaohong JIA, Fei GUO. Numerical analysis of the effect of temperature and its fluctuations on the vulcanization process of rubber seals [J]. CIESC Journal, 2024, 75(2): 715-726.
[15]	Xueyun WANG, Xiaobing YU, Wanwang PENG, Yansong SHEN. Numerical study on combustion zone behaviors of a slagging gasifier [J]. CIESC Journal, 2024, 75(2): 659-674.