天然铁矿石为载氧体的准东煤化学链燃烧特性

葛晖骏; 沈来宏; 顾海明; 宋涛; 蒋守席

天然铁矿石为载氧体的准东煤化学链燃烧特性

基金项目:

国家自然科学基金 51276037, 51406035, 51476029

东南大学优秀博士学位论文基金 YBJJ1544

江苏省高等学校研究生创新计划 KYLX15_0065

详细信息

中图分类号: TK16
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出版历程
- 收稿日期: 2015-09-14
- 修回日期: 2015-11-16

Characteristics of Zhundong coal in chemical looping combustion with natural hematite as oxygen carrier

More Information

Corresponding author: Tel: +86-25-5771 4489, E-mail: lhshen@seu.edu.cn

摘要

摘要: 采用煤化学链燃烧方式可望抑制高钠准东煤燃烧结渣问题、提高其利用效率。为此, 选择天然铁矿石作为载氧体, 在小型流化床反应器内对准东煤燃烧性能及钠的迁移特性进行了研究。结果表明, 在850-1 000℃下, 准东煤的碳转化率和转化速率明显高于其他煤种; 同时, 钠以高熔点Na₂O·Al₂O₃·6SiO₂的形式存在于飞灰中, 从而达到抑制结渣的目的。在循环10次实验中, 随着循环次数的增加, 铁矿石反应活性提高而钠在飞灰中的含量减少。
- 准东煤 /
- 化学链燃烧 /
- 结渣 /
- 高钠煤 /
- 天然铁矿石 /
- 载氧体
Abstract: The characteristics of high-sodium Zhundong coal in chemical looping combustion (CLC) as well as the migration of sodium upon combustion were investigated in a fluidized-bed reactor with natural hematite as the oxygen carrier, in order to mitigate the severe slagging and fouling problems and enhance the utilization efficiency of Zhundong coal.The results indicated that the carbon conversion and reaction rate for Zhundong coal in CLC were evidently higher than those of other coals at 850-1 000℃; aluminosilicate Na₂O·Al₂O₃·6SiO₂ of high melting point is formed in the CLC process, which is effective to mitigate the severe slagging and fouling problems.During a 10-cycle CLC test, the reactivity of hematite increases with the increase of cycle number, whereas the sodium content in the CLC fly ash is reduced.
- Zhundong coal /
- chemical looping combustion /
- slagging and fouling /
- high sodium coal /
- natural hematite /
- oxygen carrier

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图 1 基于天然铁矿石载氧体的煤化学链燃烧原理示意图

Figure 1. Schematic diagram for the chemical looping combustion (CLC) of coal with natural hematite as the oxygen carrier

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图 2 小型流化床化学链燃烧反应装置示意图

Figure 2. Schematic diagram of the experimental setup for the chemical looping combustion (CLC)

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图 3 分别以神华烟煤 (a)、徐州烟煤 (b)、淮北无烟煤 (c)、准东煤 (d) 和水洗后的准东煤 (e) 为燃料, 水蒸气为气化介质，反应温度为850-1000℃时的相对气体浓度

Figure 3. Relative cumulative fractions of each component (CO₂, CO, H₂ and CH₄) in the chemical looping combustion (CLC) of SH (a), XZ (b), HB (c), ZD (d) and deposit ZD (e) coals with hematite as the oxygen carrier at 850-1000℃

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图 4 900℃下分别以神华烟煤、徐州烟煤、淮北无烟煤和准东煤为燃料时的碳转化率随时间的变化

Figure 4. Carbon conversion for SH, XZ, HB and ZD coals versus time during the chemical looping combustion at 900℃

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图 5 900℃下分别以神华烟煤、徐州烟煤、淮北无烟煤和准东煤为燃料时的碳转化速率随时间的变化

Figure 5. Carbon conversion rate with SH, XZ, HB and ZD versus time during the chemical looping combustion at 900℃

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图 6 900℃下循环次数对相对气体浓度的影响

Figure 6. Relative concentration of CO₂, CO, H₂ and CH₄ released versus the cycle number during the 10-cycle CLC test at 900℃

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表 1 神华烟煤、徐州烟煤、淮北无烟煤以及准东煤的元素分析和工业分析

Table 1. Proximate analysis and ultimate analysis of Shenhua bitumite (SH), Xuzhou bitumite (XZ), Huaibei anthracite (HB) and Zhundong coal (ZD)

Coal	Proximate analysis w_ar/%				Ultimate analysis w_ar/%
Coal	M	V	FC	A	C	H	O	N	S
SH	6.01	35.10	54.13	4.76	69.57	4.30	13.81	1.03	0.52
XZ	1.53	12.82	71.32	14.33	78.47	3.61	6.13	1.33	0.34
HB	1.01	8.82	80.35	9.82	80.85	4.62	0.99	1.39	1.32
ZD	12.15	28.54	53.90	5.41	65.69	4.98	16.33	0.85	1.78

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表 2 神华烟煤、徐州烟煤、淮北无烟煤以及准东煤的灰分分析

Table 2. Ash composition analysis of Shenhua bitumite, Xuzhou bitumite, Huaibei anthracite and Zhundong coal

Coal	Ash component w_ar/%
Coal	SiO₂	Al₂O₃	CaO	MgO	Fe₂O₃	Na₂O	K₂O	SO₂	P₂O₅
SH	35.41	13.23	20.18	4.03	8.79	0.34	0.91	13.75	2.65
XZ	26.13	11.39	22.50	10.09	12.11	0.55	0.29	14.43	1.56
HB	24.35	13.99	23.29	4.11	15.99	0.43	0.91	15.96	0.19
ZD	10.58	12.60	24.27	8.20	19.91	7.50	0.42	13.75	2.03

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表 3 南非铁矿石的化学组成

Table 3. Elemental analysis of the hematite oxygen carrier

Content w/%
Fe₂O₃	Al₂O₃	SiO₂	TiO₂	P₂O₅	CaO	K₂O	others
83.21	5.37	7.06	0.08	0.38	0.23	0.03	3.64

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表 4 准东煤空气燃烧成灰和化学链飞灰中各元素的含量

Table 4. Elemental concentrations of oxy-burned ash and CLC ash

	Content w/%
	SiO₂	Al₂O₃	CaO	MgO	Fe₂O₃	Na₂O	K₂O	SO₂
Oxy-burned ash	10.18	11.60	24.67	8.20	19.81	7.50	0.44	13.79
CLC ash	20.76	19.31	14.11	6.33	24.06	5.75	0.08	8.21

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表 5 准东煤燃烧成灰、化学链飞灰以及反应后铁矿石的XRD分析

Table 5. XRD analysis results for the oxy-burned ash, CLC ash and reacted hematite (trace, about 3%; minor, about 10%; and major, above 10%)

Residue type	Fluidizing/ Gasification agent	Composition
Oxy-burned ash	O₂	Fe₂O₃(major), CaSO₄(major), NaCl (minor), CH₃COONa (trace)
CLC ash	N₂	Fe₃O₄(major), CaS (major), Al₂O₃·6SiO₂(minor)，NaCl (trace)
CLC ash	CO₂	Fe₃O₄(major), CaS (major), Na₂O·Al₂O₃·6SiO₂(trace)
CLC ash	H₂O	Fe₃O₄(major), CaS (major), Na₂O·Al₂O₃·6SiO₂(minor)
Reacted hematite	-	Fe₃O₄(major), SiO₂(major), Al₂O₃(major), Na₃FeO₂(minor), Fe₂SiO₄(minor)

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表 6 准东煤空气燃烧成灰和多次循环后化学链飞灰中钠的含量 (xC：x循环后的化学链飞灰)

Table 6. Sodium content in the oxy-burned ash and CLC ash after different cycles (xC, CLC ash after x cycles) during the 10-cycle CLC test at 900℃

	Oxy-burned ash	1C	2C	4C	6C	8C	10C
Sodium content w/%	7.50	5.75	5.43	5.12	4.88	4.67	4.52

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参考文献(21)

[1]	HAMMOND G P, AKWE S S O, WILLIAMS S.Techno-economic appraisal of fossil-fuelled power generation systems with carbon dioxide capture and storage[J].Energy, 2011, 36(2):975-984. doi: 10.1016/j.energy.2010.12.012
[2]	李虹, 董亮, 段红霞.中国可再生能源发展综合评价与结构优化研究[J].资源科学, 2011, 33(3):431-440. http://www.cnki.com.cn/Article/CJFDTOTAL-ZRZY201103009.htm LI Hong, DONG Liang, DUAN Hong-xia.On comprehensive evaluation and optimization of renewable energy development in China[J].Resour Sci, 2011, 33(3):431-440. http://www.cnki.com.cn/Article/CJFDTOTAL-ZRZY201103009.htm
[3]	刘敬, 王智化, 项飞鹏.准东煤中碱金属的赋存形式及其在燃烧过程中的迁移规律实验研究[J].燃料化学学报, 2014, 42(3):316-322. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18373.shtml LIU Jing, WANG Zhi-hua, XIANG Fei-peng.Modes of occurrence and transformation of alkali metals in Zhundong coal during combustion[J].J Fuel Chem Technol, 2014, 42(3):316-322. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18373.shtml
[4]	翁青松, 王长安, 车得福.准东煤碱金属赋存形态及对燃烧特性的影响[J].燃烧科学与技术, 2014, 20(3):216-221. http://www.cnki.com.cn/Article/CJFDTOTAL-RSKX201403004.htm WENG Qing-song, WANG Chang-an, CHE De-fu, FU Zi-wen.Alkali metal occurrence mode and its influence on combustion characteristics in Zhundong coals[J].J Combust Sci Technol, 2014, 20(3):216-221. http://www.cnki.com.cn/Article/CJFDTOTAL-RSKX201403004.htm
[5]	杨忠灿, 刘家利, 何红光.新疆准东煤特性研究及其锅炉选型[J].热力发电, 2010, 39(8):38-40. http://www.cnki.com.cn/Article/CJFDTOTAL-RLFD201008013.htm YANG Zhong-can, LIU Jia-li, HE Hong-guang.Study on properties of zhundong coal in Xinjiang region and type-selection for boilers burning this coal sort[J].Therm Power Gen, 2010, 39(8):38-40. http://www.cnki.com.cn/Article/CJFDTOTAL-RLFD201008013.htm
[6]	邱忠, 梁进林.循环流化床锅炉燃烧新疆准东五彩湾煤的对策探讨[J].应用能源技术, 2013, (12):16-19. QIU Zhong, LIANG Jin-lin.Circulating fluidized bed boiler burning Xinjiang Wucaiwan area in Zhundong coal measures[J].Appl Energ Technol, 2013, (12):16-19.
[7]	杨忠灿, 刘家利, 姚伟.准东煤灰沾污指标研究[J].洁净煤技术, 2013, 19(2):81-84. http://www.cnki.com.cn/Article/CJFDTOTAL-JJMS201302023.htm YANG Zhong-can, LIU Jia-li, YAO Wei.Fouling index of Zhundong coal ash[J].Clean Coal Technol, 2013, 19(2):81-84. http://www.cnki.com.cn/Article/CJFDTOTAL-JJMS201302023.htm
[8]	VAN EYK P J, ASHMAN P J, NATHAN G J.Mechanism and kinetics of sodium release from brown coal char particles during combustion[J].Combust Flame, 2011, 158(12):2512-2523. doi: 10.1016/j.combustflame.2011.05.005
[9]	SCHURMANN H, MONKHOUSE P B, UNTERBERGER S.In situ parametric study of alkali release in pulverized coal combustion:Effects of operating conditions and gas composition[J].Proc Combust Inst, 2007, 31(2):1913-1920. doi: 10.1016/j.proci.2006.07.040
[10]	SONG T, SHEN T, SHEN L.Evaluation of hematite oxygen carrier in chemical-looping combustion of coal[J].Fuel, 2013, 104:244-252. doi: 10.1016/j.fuel.2012.09.030
[11]	GU H, SHEN L, XIAO J.Iron ore as oxygen carrier improved with potassium for chemical looping combustion of anthracite coal[J].Combust Flame, 2012, 159(7):2480-2490. doi: 10.1016/j.combustflame.2012.03.013
[12]	GU H, SHEN L, XIAO J, CHEN D, ZHANG S.K₂CO₃-decorated iron ore for chemical looping combustion of anthracite in a 1kWth reactor.Proceedings of the 9th China-Korea Workshop on Clean Energy Technology, Huangshan, China, 2012.
[13]	SONG T, SHEN L, XIAO J.Nitrogen transfer of fuel-N in chemical looping combustion[J].Combust Flame, 2012, 159(3):1286-1295. doi: 10.1016/j.combustflame.2011.10.024
[14]	张思文, 沈来宏, 肖军.基于碱金属和过渡金属修饰铁矿石载氧体的煤催化燃烧[J].燃料化学学报, 2015, 40(10):1179-1187. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18041.shtml ZHANG Si-wen, SHEN Lai-hong, XIAO Jun, GU Hai-ming, SONG Tao.Catalytic combustion of coal using alkali and transition metals loaded on iron ore oxygen carrier[J].J Fuel Chem Technol, 2015, 40(10):1179-1187. http://rlhxxb.sxicc.ac.cn/CN/abstract/abstract18041.shtml
[15]	WU H, QUYN D M, LI C Z.Volatilisation and catalytic effects of alkali and alkaline earth metallic species during the pyrolysis and gasification of Victorian brown coal.Part Ⅲ.The importance of the interactions between volatiles and char at high temperature[J].Fuel, 2002, 81(8):1033-1039. doi: 10.1016/S0016-2361(02)00011-X
[16]	QUYN D M, WU H, BHATTACHARYA S P, LI C Z.Volatilisation and catalytic effects of alkali and alkaline earth metallic species during the pyrolysis and gasification of Victorian brown coal.Part Ⅱ.Effects of chemical form and valence.Fuel, 2002, 81(2):151-158. doi: 10.1016/S0016-2361(01)00128-4
[17]	LYNGFELT A.Chemical-looping combustion of solid fuels-status of development[J].Appl Energy, 2014, 113:1869-1873. doi: 10.1016/j.apenergy.2013.05.043
[18]	KOSMINSKI A, ROSS D P, AGNEW J B.Reactions between sodium and kaolin during gasification of a low-rank coal[J].Fuel Process Technol, 2006, 87(12):1051-1062. doi: 10.1016/j.fuproc.2005.06.004
[19]	WALL C J, GRAVES J T, ROBERTS E J.How to burn salty sludges[J].Chem Eng, 1975, 82(8):77-82.
[20]	KOELBEL H, GIEHRING H.Action of alkali promoters upon iron catalysts.VI.Influence of potassium carbonate upon selectivity[J].Brennst Chem, 1963, 44(11).
[21]	LINFENG Z, PEIMIN GUO, PEI Z.Study on catalytic mechanism of gasbased reduction of iron ore[J].Iron Steel Vanadium Titanium, 2008, 39(1):1-5.