先锋褐煤在水热处理过程中的结构演绎

刘鹏; 周扬; 鲁锡兰; 王岚岚; 潘铁英; 张德祥

先锋褐煤在水热处理过程中的结构演绎

1.
华东理工大学能源化工系煤气化及能源化工教育部重点实验室, 上海 200237
2.
华东理工大学分析测试中心, 上海 200237

基金项目:

国家重点基础研究发展规划 973计划, 2011CB201304

详细信息

中图分类号: TQ520.61
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- 被引次数: 0
出版历程
- 收稿日期: 2015-09-14
- 修回日期: 2015-11-01
- 网络出版日期: 2022-03-23
- 刊出日期: 2016-02-01

Structural evolution of Xianfeng lignite during hydrothermal treatment

1.
Department of Chemical Engineering for Energy Resources, East China University of Science & Technology, Key Laboratory of Coal Gasification and Energy Chemical Engineering of Ministry of Education, Shanghai 200237, China
2.
Analysis and Research Center, East China University of Science and Technology, Shanghai 200237, China

More Information

Corresponding author: Tel: 021-64252367，E-mail: zdx@ecust.edu.cn

摘要

摘要: 以先锋褐煤 (XF) 为原料, 在高压反应釜中考察了水热处理过程中褐煤的结构变化, 通过¹³C固体核磁共振 (NMR) 和傅里叶变换红外光谱进行了分析表征。结果表明, 在低于240℃的水热处理条件下, 煤有机分子结构中的弱化学键有一定断裂, 含氧官能团逐步减少; 水中氢以离子形态迁移至褐煤中, 处理后褐煤结构中甲基比例先增加后减少, 次甲基比例由原煤的4.80%增加至XF-240的13.16%;释放的气体中主要是CO₂, 烃类气体组分随处理温度的升高略有增加。当水热处理温度高于240℃时, 褐煤中部分共价键开始断裂, 释放的烃类气体 (C_1-4) 由240℃时的2.13%增加至300℃时的8.59%, 脂肪碳比例由XF-240的44.83%降低至XF-300的39.49%, 与氧连接的碳比例由XF-240的12.57%降低至XF-300的1.49%。水热处理对褐煤的脱氧提质效果显著, 300℃时氧含量降低约30%, 芳香碳比例增加至60.50%, 比原煤提高19%。
- 褐煤 /
- 水热处理 /
- ¹³C固体核磁共振 /
- 碳结构 /
- 氢转移
Abstract: Xianfeng lignite (XF) was used as raw material to investigate its structural evolution during hydrothermal treatment in a 500 mL autoclave.The structure was characterized by solid state ¹³C nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FT-IR).The results show that the carbon contents increase and oxygen contents decrease after hydrotnermal treatment.The weak bonds in lignite are broken and the oxygen functional groups decrease gradually during hydrothermal treatment below 240℃.Hydrogen is donated from water to lignite through ionic pathway and transferred into lignite.The methyl carbon increases at 200℃ and then decreases.The methenyl carbon increases from 4.80% in XF to 13.16% in XF-240.The released gas is mainly CO₂ during hydrothermal treatment.The hydrocarbon composition in released gas increases with the treated temperature.The covalent bonds are broken above 240℃.The hydrocarbon composition in released gas increases from 2.13% at 240℃ to 8.59% at 300℃.The aliphatic carbon in lignite deceases from 44.83% in XF-240 to 39.49% in XF-300.The oxygen-linked carbon in lignite decreases from 12.57% in XF-240 to 1.49% in XF-300.Hydrothermal treatment plays a role in deoxygenation and upgrading of raw lignite.The oxygen contents decrease by about 30% and the aromatic carbon increases to 60.50% at 300℃.
- lignite /
- hydrothermal treatment /
- ¹³C-NMR /
- carbon structure /
- hydrogen transfer

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图 1 ¹³C-NMR波谱谱图

Figure 1 ¹³C-NMR spectra

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图 2 ¹³C-NMR谱图分峰拟合模拟图

Figure 2 Fitted ¹³C-NMR spectra

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图 3 FT-IR光谱谱图

Figure 3 Fitted FT-IR spectra

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图 4 XF褐煤水热处理结构演绎图

Figure 4 Schematic for structural evolution of XF during hydrothermal treatment

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表 1 褐煤干燥提质工艺参数

Table 1 Comparison of process parameters of lignite upgrading

Project	Evaporation drying		Non-evaporation drying
Project	WTA	HPU	D-K	MTE	HTD
Temperature t/℃	100-120	105-110	180-240	150-220	220-300
Operating pressure p/MPa	0.30-0.40	atmospheric	17	10	saturated vapor pressure
Heavy water absorption	yes	no	no	no	no
Pore structure	unchanged	decrease	decrease	decrease	decrease
Oxygen content	unchanged	unchanged	decrease	decrease	decrease
Dewaterability t/h	110	110	1	25	-

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表 2 先锋褐煤处理前后工业与元素分析

Table 2 Proximate and ultimate analyses of XF and treated XF

Sample	Recovery ^a w/%	Proximate analyses w/%			Ultimate analyses w_daf /%
Sample	Recovery ^a w/%	A_d	V_daf	FC_daf	C	H	N	S	O ^c
XF	-	8.42	52.58	47.42	71.26	5.06	2.25	0.94	20.49
XF-200 ^b	93.15	8.10	51.51	48.49	72.90	5.07	2.35	0.81	18.87
XF-220	91.89	8.53	49.12	50.88	72.24	4.91	2.42	0.86	19.56
XF-240	90.11	8.45	47.73	52.27	73.11	4.82	2.40	0.87	18.79
XF-260	88.32	8.25	47.85	52.15	75.33	4.65	2.39	0.76	16.87
XF-300	81.76	9.22	43.05	56.95	77.65	4.94	2.22	0.82	14.37
^a: recovery is the mass ratio of treated lignite to raw lignite during hydrothermal treatment; ^b: “XF-200” indicates the IM was treated at 200℃for 30min; ^c: by difference

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表 3 先锋褐煤¹³C-NMR中不同类型碳对应的化学位移

Table 3 Main assignments of chemical shift values for different structural carbons in solid-state ¹³C-NMR spectra of XF lignite

Assignment	Location	Chemical shift δ	Character
Aliphatic methyl	R-CH₃	14-22	f_al³
Aromatic methyl		22-26	f_al^a
Methylene	-CH₂,	26-37	f_al²
Quaternery sp³ C	-CH--C	37-50	f_al¹, f_al^*
Oxygen aliphatic carbon	R-O-R,	50-95	f_al^O
Protonated aromatic carbon		95-124	f_a^H
Bridging ring junction aromatic carbon		124-137	f_a^B
Aliphatic substituted aromatic carbon		137-149	f_a^S
Oxygen aromatic carbon		149-164	f_a^O
Carboxyl, quinone and carbonyl carbon	RCOOH, RCOR	164-220	f_a^CC
f_al³: fraction of aliphatic methyl carbon; f_al^a: fraction of aromatic methyl carbon; f_al²: fraction of methylene carbon; f_al¹: fraction of methine carbon; f_al^*: fraction of carbon that is aliphatic and either quaternary, methyl, or mobile methylene; f_al^O: fraction of total carbon associated with aliphatic ethers and alcohols; f_a^H: protonated aromatic carbon; f_a^B: bridgehead aromatic carbon; f_a^S: alkyl substituted aromatic carbon; f_a^O: oxygenated aromatic carbon; f_a^CC: fraction of carbonyl, quinone and carboxyl carbons

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表 4 XF褐煤含氧官能团在FT-IR光谱谱图中对应的位置

Table 4 Band assignments of oxygen functional groups for the FT-IR spectrum of XF lignite

Wavenumber σ/ cm^-1	Assignment
1690-1720	C-O, ketone, aldehyde and -COOH
1600-1660	conjugated C=O
1450-1600	aromatic C=C
1375-1450	CH₃-Ar, CH₃ and CH₂
1110-1300	C-O phenol
1000-1110	ash, alkyl ethers,
	Si-O and aryl ethers

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表 5 先锋褐煤处理前后不同类型有机碳的分布

Table 5 Carbon structure distributions of the raw and treated XF

Sample	Distribution /%
Sample	f_al³	f_al^a	f_al²	f_al¹+f_al^*	f_al^O	f_a^H	f_a^B	f_a^O	f_a^S	f_a^CC
XF	12.77	14.00	11.35	4.80	5.27	8.91	26.61	5.42	7.22	3.65
XF-200	16.95	15.38	7.81	5.14	1.49	11.80	25.61	7.12	5.27	3.43
XF-220	7.99	17.65	12.71	5.07	1.75	8.65	29.76	3.94	10.18	2.29
XF-240	8.11	17.13	6.43	13.16	0	5.39	31.82	5.38	8.29	4.28
XF-260	6.92	20.52	10.33	6.29	0	6.30	29.21	9.79	8.78	1.87
XF-300	10.34	16.05	9.31	3.79	0	3.86	19.36	35.79	1.49	0
f_al³: fraction of aliphatic methyl carbon; f_al^a: fraction of aromatic methyl carbon; f_al²: fraction of methylene carbon; f_al¹: fraction of methine carbon; f_al^*: fraction of carbon that is aliphatic and either quaternary, methyl, or mobile methylene; f_al^O: fraction of total carbon associated with aliphatic ethers and alcohols; f_a^H: protonated aromatic carbon; f_a^B: bridgehead aromatic carbon; f_a^S: alkyl substituted aromatic carbon; f_a^O: oxygenated aromatic carbon; f_a^CC: fraction of carbonyl, quinone and carboxyl carbons

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表 6 先锋褐煤FT-IR光谱谱图上含氧官能团区域的变化

Table 6 Oxygen functional groups band of the raw and treated XF for the FT-IR spectrum

Peak	Position σ/cm^-1	Assignment	XF area percentage /%	XF-240 area percentage /%
1	1035	alkyl ethers，Si-O	8.62	11.45
2	1100	aryl ethers	6.82	5.69
3	1167	C-O phenol	2.42	0.45
4	1207	C-O phenol	4.40	17.36
5	1269	C-O phenol	3.39	0.42
6	1310	C-O phenol	3.97	4.35
7	1376	CH₃-Ar	5.92	2.20
8	1442	CH₃, CH₂	8.16	13.02
9	1502	aromatic C=C	2.12	2.37
10	1556	aromatic C=C	5.60	0.23
11	1588	aromatic C=C	16.54	8.63
12	1620	conjugated C=O	13.48	26.53
13	1656	conjugated C=O	0.61	0.68
14	1696	carboxyl acids	17.94	6.63

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表 7 褐煤在水热处理过程中析出气体组分的变化

Table 7 Variation of gas composition during hydrothermal treatment

Temperature t/℃	Volume percentage φ/%
Temperature t/℃	H₂	CO	CO₂	CH₄	C₂	C₃	C₄
200	3.41	2.96	92.83	0.80	-	-	-
220	2.11	2.46	94.07	1.00	0.20	0.14	0.02
240	1.17	2.69	94.02	1.58	0.31	0.20	0.03
260	5.91	2.75	88.61	1.97	0.45	0.27	0.04
300	3.39	2.01	86.02	6.11	1.48	0.83	0.16
^*：the hydrothermal treatment temperature

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参考文献(33)

[1]	BP Group.BP Statistical review of world energy (2014.6)[EB/OL].http://www.bp.com/en/global/corporate/about-bp/energy-economics/statistical-review-of-world-energy.html.
[2]	尚建选, 马宝岐, 张秋民, 沈和平.低阶煤分质转化多联产技术[M].北京:煤炭工业出版社, 2013. SHANG Jian-xuan, MA Bao-qi, ZHANG Qiu-min, SHEN He-ping.Low rank coal mass transfer and poly-generation technology[M].Beijing:Press of Coal Industry, 2013.
[3]	YU J, TAHMASEBI A, HAN Y, YIN F, LI X.A review on water in low rank coals:The existence, interaction with coal structure and effects on coal utilization[J].Fuel Process Technol, 2013, 106:9-20.
[4]	KATAMBULA H, GUPTA R.Low-grade coals:A review of some prospective upgrading technologies[J].Energy Fuels, 2009, 23(7):3392-3405. doi: 10.1021/ef801140t
[5]	周剑林, 王永刚, 黄鑫, 张书, 林雄超.低阶煤中含氧官能团分布的研究[J].燃料化学学报, 2013, 42(2):134-138. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18113.shtml ZHOU Jian-lin, WANG Yong-gang, HUANG Xin, ZHANG Shu, LIN Xiong-chao.Determination of O-containing functional groups distribution in low-rank coals by chemical titration[J].J Fuel Chem Technol, 2013, 42(2):134-138. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18113.shtml
[6]	RWE Power.The WTA technology:An advanced method of processing and lignite[EB/OL].http://www.Rwe.com/web/cms/en/213182/rwe-power-ag/innobations/coal-innov-ation-centre/fluidized-bed-drying-with-internal-waste-heat-utilization-wta.
[7]	朱书全.褐煤提质技术开发现状及分析[J].洁净煤技术, 2011, 17(1):1-4. http://www.cnki.com.cn/Article/CJFDTOTAL-JJMS201101002.htm ZHU Shu-quan.Development status and analysis of lignite quality improvement technol[J].Clean Coal Technol, 2011, 17(1):1-4. http://www.cnki.com.cn/Article/CJFDTOTAL-JJMS201101002.htm
[8]	戴和武, 谢可玉.褐煤利用技术[M].北京:煤炭工业出版社, 1999. DAI He-wu, XIE Ke-yu.Lignite utilization technology[M].Beijing:Press of Coal Industry, 1999.
[9]	BERGINS C.Kinetics and mechanism during mechanical/thermal dewatering of lignite[J].Fuel, 2003, 82(4):355-364. doi: 10.1016/S0016-2361(02)00310-1
[10]	YU Y J, LIU J Z, CEN K F.Properties of coal water slurry prepared with the solid and liquid products of hydrothermal dewatering of brown coal[J].Ind Eng Chem Res, 2014, 53:4511-4517. doi: 10.1021/ie5000592
[11]	BUTLER C J, GREEN A M, CHAFFEE A L.The fate of trace elements during MTE and HTD dewatering of Latrobe Valley brown coals[J].Coal Prep, 2007, 27(4):210-229. doi: 10.1080/07349340701640844
[12]	MAPSTONE J O.Effect of hydrothermal pretreatment on coal structure and the mild gasification process[J].Energy Fuels, 1991, 5(5):695-700. doi: 10.1021/ef00029a011
[13]	FAVAS G, JACKSON W R.Hydrothermal dewatering of lower rank coals.1.Effects of process conditions on the properties of dried product[J].Fuel, 2003, 82(1):53-57. doi: 10.1016/S0016-2361(02)00192-8
[14]	FAVAS G, JACKSON W R.Hydrothermal dewatering of lower rank coals.2.Effects of coal characteristics for a range of Australian and international coals[J].Fuel, 2003, 82(1):59-69. doi: 10.1016/S0016-2361(02)00191-6
[15]	FAVAS G, JACKSON W R, MARSHALL M.Hydrothermal dewatering of lower rank coals.3.High-concentration slurries from hydrothermally treated lower rank coals[J].Fuel, 2003, 82(1):71-79. doi: 10.1016/S0016-2361(02)00190-4
[16]	SAKAGUCHI M, LAURSEN K, NAKAGAWA H, MIURA K.Hydrothermal upgrading of Loy Yang Brown coal-Effect of upgrading conditions on the characteristics of the products[J].Fuel Process Technol, 2008, 89:391-396. doi: 10.1016/j.fuproc.2007.11.008
[17]	常鸿雁, 徐文娟, 张德祥, 高晋生.加压水蒸气下年轻煤脱氧改质的研究[J].煤炭转化, 2005, 28(1):25-29. http://www.cnki.com.cn/Article/CJFDTOTAL-MTZH200501005.htm CHANG Hong-yan, XU Wen-juan, ZHANG De-xiang, GAO Jin-sheng.Study on the deoxy-modification of low rank coals under pressurized vapour conditions[J].Coal Convers, 2005, 28(1):25-29. http://www.cnki.com.cn/Article/CJFDTOTAL-MTZH200501005.htm
[18]	刘红缨, 郜翔, 张明阳, 朱彦敏, 朱书全.水热法改性褐煤及含氧官能团与水相互作用的研究[J].燃料化学学报, 2014, 42(3):284-289. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18368.shtml LIU Hong-ying, GAO Xiang, ZHANG Ming-yang, ZHU Yan-ming, ZHU Shu-quan.Study on lignite modified by hydrothermal and the interaction between the oxygen containing functional groups and water[J].J Fuel Chem Technol, 2014, 42(3):284-289. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18368.shtml
[19]	黄鑫, 张书, 林雄超, 王永刚, 徐敏.低温加压热解脱氧对胜利褐煤亲水性的影响[J].燃料化学学报, 2013, 41(12):1409-1414. doi: 10.1016/S1872-5813(14)60005-0 HUANG Xin, ZHANG Shu, LIN Xiong-chao, WANG Yong-gang, XU Min.Deoxygenation effect on hydrophilicity changes of Shengli lignite during pressurized pyrolysis at low temperature[J].J Fuel Chem Technol, 2013, 41(12):1409-1414. doi: 10.1016/S1872-5813(14)60005-0
[20]	INOUE T, OKUMA O, MASUDA K, YASUMURO M, MIURA K.Hydrothermal treatment of brown coal to improve the space time yield of a direct liquefaction reactor[J].Energy Fuels, 2012, 26(4):2198-2203. doi: 10.1021/ef300095s
[21]	INOUE T, OKUMA O, MASUDA K, YASUMURO M, MIURA K.Direct liquefaction of brown coal using a 0.1 ton/day process development unit:Effect of hydrothermal treatment on scale deposition and liquefaction yield[J].Energy Fuels, 2012, 26(9):5821-5827. doi: 10.1021/ef300999r
[22]	FU J, WANG J.Enhanced slurryability and rheological behaviors of two low-rank coals by thermal and hydrothermal pretreatments[J].Powder Technol, 2014, 266:183-190. doi: 10.1016/j.powtec.2014.06.034
[23]	YU Y J, LIU J Z, WANG R, ZHOU J, CEN K F.Effect of hydrothermal dewatering on the slurryability of brown coals[J].Energ Convers Manage, 2012, 57:8-12. doi: 10.1016/j.enconman.2011.11.016
[24]	葛立超, 张彦威, 应芝, 王智化, 周俊虎, 岑可法.水热处理对我国典型褐煤气化特性的影响[J].中国电机工程学报, 2013, 33(32):14-20. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGDC201332004.htm GE Li-chao, ZHANG Yan-wei, YING Zhi, WANG Zhi-hua, ZHOU Jun-hu, CEN Ke-fa.Influence of the hydrothermal dewatering on the gasification characteristics of typical chinese lignite[J].Proc CSEE, 2013, 33(32):14-20. http://www.cnki.com.cn/Article/CJFDTOTAL-ZGDC201332004.htm
[25]	相建华, 曾凡桂, 李彬, 张莉, 李美芬, 梁虎珍.成庄无烟煤大分子结构模型及其分子模拟[J].燃料化学学报, 2013, 41(4):391-399. doi: 10.1016/S1872-5813(13)60022-5 XIANG Jian-hua, ZEGN Fan-gui, LI Bin, ZHAGN Li, LI Mei-fen, LIANG Hu-zhen.Construction of macromolecular structural model of anthracite from Chengzhuang coal mine and its molecular simulation[J].J Fuel Chem Technol, 2013, 41(4):391-399. doi: 10.1016/S1872-5813(13)60022-5
[26]	YAN J, BAI Z, BAI J, GUO Z, LI W.Effects of organic solvent treatment on the chemical structure and pyrolysis reactivity of brown coal[J].Fuel, 2014, 128:39-45. doi: 10.1016/j.fuel.2014.03.001
[27]	WEI Z, GAO X, ZHANG D, DA J.Assessment of thermal evolution of kerogen geopolymers with their structural parameters measured by solid-state ¹³C NMR spectroscopy[J].Energy Fuels, 2005, 19(1):240-250. doi: 10.1021/ef0498566
[28]	LIU P, WANG L L, ZHOU Y, PAN T Y, LU X L, ZHANG D X.Effect of hydrothermal treatment on the structure and pyrolysis product distribution of Xiaolongtan lignite[J].Fuel, 2016, 164:110-118. doi: 10.1016/j.fuel.2015.09.092
[29]	WU D, LIU G, SUN R, FAN X.Investigation of structural characteristics of thermally metamorphosed coal by FTIR spectroscopy and X-ray diffraction[J].Energy Fuels, 2013, 27(10):5823-5830. doi: 10.1021/ef401276h
[30]	梁虎珍, 王传格, 曾凡桂, 李美芬, 相建华.应用红外光谱研究脱灰对伊敏褐煤结构的影响[J].燃料化学学报, 2014, 42(2):129-137. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18345.shtml LIANG Hu-zhen, WANG Chuan-ge, ZENG Fan-gui, LI Mei-fen, XIANG Jian-hua.Effect of demineralization on lignite structure from Yinmin coalfield by FT-IR investigation[J].J Fuel Chem Technol, 2014, 42(2):129-137. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18345.shtml
[31]	刘鹏, 王岚岚, 张德祥, 鲁锡兰, 潘铁英.水热处理对褐煤提质及其热解产物分布的影响[J].洁净煤技术, 2015, 21(1):45-49. doi: 10.7464/ksct.2015.21.1.045 LIU Peng, WANG lan-lan, ZHANG De-xiang, LU Xi-lan, PAN Tie-ying.Effects of hydrothermal treatment on lignite upgrading and distribution of pyrolysis products[J].Clean Coal Technol, 2015, 21(1):45-49. doi: 10.7464/ksct.2015.21.1.045
[32]	ZENG C, FAVAS G, WU H, CHAFFEE A L, HAYASHI J, LI C Z.Effects of pretreatment in steam on the pyrolysis behavior of Loy Yang brown coal[J].Energy Fuels, 2006, 20(1):281-286. doi: 10.1021/ef0502406
[33]	SISKINA M, KATRITZKY A R.A review of the reactivity of organic compounds with oxygen-containing functionality in superheated water[J].J Anal Appl Pyrolysis, 2000, 54(1/2):193-214. http://www.baidu.com/link?url=OaGkor5fsIAa-FFwdUkTFjavSam8mH-DrTdIzWQr7jdFisRVmqrbPpFizsiIM1pcsxbzf1P9vAdxwysX0VL2PktHRIVGZcchkJviZKLvcWWZ66eCId4ODI707p7Jlr4AEnqn2Kaw822pV1Nchi1HO0WZd9lZt97pGYDYdDov7_utKWCmoabKaH-bwncoEfBYsKXHADxhSSNYHlRVdJ2YabC1g-ICN-H8xJTlWSsdzwdOJGCaUmSrJxLbRKM7us1_aBhyT7jkHxhG19E7p9hf2rzFiRBrzBRgis82Q7D35GV8XbF201pqpZLu5PkWfbn7YFF9gLWvUpzJuvFMMwfWBIfloJm6RHu5rMmkCVfqwypjg0ZypcNtW_GyCN2TKX4n&wd=&eqid=8acaa162000437310000000558bfdd25