硅钙摩尔比对准东煤燃烧过程中矿物演变及灰熔融特性的影响

doi:10.16085/j.issn.1000-6613.2021-1960

化工进展 ›› 2022, Vol. 41 ›› Issue (8): 4140-4146.DOI: 10.16085/j.issn.1000-6613.2021-1960

硅钙摩尔比对准东煤燃烧过程中矿物演变及灰熔融特性的影响

王光绪¹^,²(), 金晶¹^,²(), 张云鹏¹^,², 刘薄鉴治¹^,², 梁诗雨¹^,², 翟中媛³

^1.上海理工大学能源与动力工程学院，上海 200093
^2.上海市动力工程多相流与传热重点实验室，上海 200093
^3.上海锅炉工程有限公司，上海 200245

收稿日期:2021-09-13 修回日期:2021-12-16 出版日期:2022-08-25 发布日期:2022-08-22
通讯作者: 金晶
作者简介:王光绪（1997—），男，硕士研究生，研究方向为准东煤高效清洁利用。E-mail：372238401@qq.com。
基金资助:
国家自然科学基金(51976129)

Influence of molar ratio of silicon to calcium on mineral evolution and ash melting characteristics during the combustion process of Zhundong coal

WANG Guangxu¹^,²(), JIN Jing¹^,²(), ZHANG Yunpeng¹^,², LIU Bojianzhi¹^,², LIANG Shiyu¹^,², ZHAI Zhongyuan³

^1.School of Energy and Power Engineering, University of Shanghai for Science and Technology, Shanghai 200093, China
^2.Shanghai Key Laboratory of Multiphase Flow and Heat Transfer in Power Engineering, Shanghai 200093, China
^3.Shanghai Boiler Works Co. , Ltd. , Shanghai 200245, China

Received:2021-09-13 Revised:2021-12-16 Online:2022-08-25 Published:2022-08-22
Contact: JIN Jing

摘要/Abstract

摘要：

选择准东高钙五彩湾（WCW）煤作为研究对象，通过改变煤灰中硅钙摩尔比（M）研究煤灰熔融特性及矿物演变的变化规律，进一步借助FactSage热力学计算软件进行矿物平衡预测。研究表明：在WCW原煤灰中，矿物CaSO₄演变生成低熔点矿物Ca₂MgSi₂O₇，使得原煤灰借助灰熔融温度（AFTs）预测其结渣、玷污时出现较大偏差。对于混煤灰，当M升高至3时，相比原煤灰，其中矿物CaSO₄的分解提前，SiO₂优先与CaO反应生成熔点较低的矿物CaMgSi₂O₆，进而引起混煤灰的熔点降低；当混煤灰中M升高至5时，充足的SiO₂会与MgO发生反应，生成高熔点矿物Mg₂SiO₄，使得此时混煤灰的AFTs显著提升，改善了煤灰熔融特性。热力学计算矿物平衡结果与X射线衍射分析（XRD）结果吻合较好，吉布斯自由能结果验证了矿物演变过程的合理性。

关键词: 准东煤, 二氧化硅, 矿物演变, 灰熔融特性

Abstract:

Selecting the Zhundong high-calcium Wucaiwan (WCW) coal as the research object, the coal ash melting characteristics and mineral evolution were studied by changing the molar ratio of silicon to calcium (M) in coal ash, and the mineral balance was predicted by using FactSage thermodynamic calculation software. The results showed that in WCW raw coal ash, mineral CaSO₄evolved into mineral Ca₂MgSi₂O₇ with low melting point, which made the prediction of slagging and fouling of raw coal ash by ash melting temperatures (AFTs) had a great deviation. For mixed coal ash, when M increased to 3, compared with raw coal ash, CaSO₄ was decomposed earlier, and SiO₂ reacted with CaO preferentially to generate CaMgSi₂O₆ mineral with lower melting point, thus causing the melting point of mixed coal ash to decrease. When the M in coal ash increased to 5, sufficient SiO₂ will react with MgO to generate the high melting point mineral Mg₂SiO₄, which significantly improved the AFTs of mixed coal ash at this moment and improved the coal ash fusion characteristics. The results of thermodynamic calculation of mineral equilibrium agreed well with X-ray diffraction analysis (XRD) , and the Gibbs free energy results verified the rationality of mineral evolution process.

Key words: Zhundong coal, silica, mineral evolution, ash fusion characteristics

中图分类号:

TQ536.4

王光绪, 金晶, 张云鹏, 刘薄鉴治, 梁诗雨, 翟中媛. 硅钙摩尔比对准东煤燃烧过程中矿物演变及灰熔融特性的影响[J]. 化工进展, 2022, 41(8): 4140-4146.

WANG Guangxu, JIN Jing, ZHANG Yunpeng, LIU Bojianzhi, LIANG Shiyu, ZHAI Zhongyuan. Influence of molar ratio of silicon to calcium on mineral evolution and ash melting characteristics during the combustion process of Zhundong coal[J]. Chemical Industry and Engineering Progress, 2022, 41(8): 4140-4146.

图/表 10

表1 五彩湾原煤的工业分析与元素分析（质量分数）

工业分析/%					元素分析/%
M_ad	A_ad	V_ad	FC_ad		C	H	N	S	O
6.90	3.77	29.35	59.98		70.82	3.85	0.30	0.64	13.72

表2 五彩湾原煤的灰成分分析

成分	质量分数/%
Na₂O	4.41
CaO	29.50
K₂O	1.03
MgO	10.52
Fe₂O₃	5.04
SiO₂	10.45
SO₃	28.42
Al₂O₃	6.25

图1 水平管式炉示意图

图2 五彩湾原煤灰及混煤灰的灰熔融温度变化

图3 在不同温度下五彩湾原煤灰及M为3、5时混煤灰的XRD图谱11—NaAlSi2O6；12—Ca2MgSi2O7；13—Ca3MgSi2O8；14—NaFeSi2O6；15—NaAlSiO4；16—KAlSi3O8；17—Ca3Fe(SiO4)3；18—Mg2SiO4；19—Fe2SiO4；20—Mg2Al4Si5O18；21—MgSiO3

1—CaSO4；2—CaAl2Si2O8；3—NaAlSi3O8；4—Ca2Al2SiO7；5—CaCO3；6—SiO2；7—MgO；8—Na2SO4；9—CaMgSiO4；10—CaMgSi2O6；

图4 SiO2/(SiO2+Ca2MgSi2O7+MgO)对矿物演变影响的相图分析结果

表3 1200℃时各组煤灰矿物演变过程的G、H变化

矿物反应	G/kJ·mol^-1	H/kJ·mol^-1	反应式编号
2CaO+MgO+2SiO₂ $→$ Ca₂MgSi₂O₇	-203.08	-185.11	（1）
3CaO+MgO+2SiO₂ $→$ Ca₃MgSi₂O₈	-237.00	-261.22	（2）
CaO+MgO+2SiO₂ $→$ CaMgSi₂O₆	-146.34	-129.89	（3）
MgO+SiO₂ $→$ MgSiO₃	-32.51	-31.01	（4）
2MgO+SiO₂ $→$ Mg₂SiO₄	-65.51	-59.15	（5）

表3 1200℃时各组煤灰矿物演变过程的G、H变化

矿物反应	G/kJ·mol^-1	H/kJ·mol^-1	反应式编号
2CaO+MgO+2SiO₂ $→$ Ca₂MgSi₂O₇	-203.08	-185.11	（1）
3CaO+MgO+2SiO₂ $→$ Ca₃MgSi₂O₈	-237.00	-261.22	（2）
CaO+MgO+2SiO₂ $→$ CaMgSi₂O₆	-146.34	-129.89	（3）
MgO+SiO₂ $→$ MgSiO₃	-32.51	-31.01	（4）
2MgO+SiO₂ $→$ Mg₂SiO₄	-65.51	-59.15	（5）

图5 五彩湾原煤灰的温度变化平衡多相图计算结果

图6 M为5时混煤灰的温度变化平衡多相图计算结果

图7 五彩湾原煤灰、M为5时混煤灰的熔融液相含量变化曲线与Na+、Ca2+含量变化曲线

参考文献 32

1	FISHER-VANDEN K. Energy in China: understanding past trends and future directions[J]. International Review of Environmental and Resource Economics, 2009, 3(3): 217-244.
2	QI X B, SONG G L, SONG W J, et al. Influence of sodium-based materials on the slagging characteristics of Zhundong coal[J]. Journal of the Energy Institute, 2017, 90(6): 914-922.
3	ZHANG Y F, ZHAO J, WEI X L, et al. Effects of alkali metals on the formation of particulate matter and adsorption of floating beads during Zhundong coal combustion[J]. Energy & Fuels, 2019, 33(6): 5422-5429.
4	HUANG Q, ZHANG Y Y, YAO Q, et al. Mineral manipulation of Zhundong lignite towards fouling mitigation in a down-fired combustor[J]. Fuel, 2018, 232: 519-529.
5	WANG X B, XU Z X, WEI B, et al. The ash deposition mechanism in boilers burning Zhundong coal with high contents of sodium and calcium: a study from ash evaporating to condensing[J]. Applied Thermal Engineering, 2015, 80: 150-159.
6	HUANG Q, LI S Q, LI G D, et al. Mechanisms on the size partitioning of sodium in particulate matter from pulverized coal combustion[J]. Combustion and Flame, 2017, 182: 313-323.
7	ZHU C, TU H, BAI Y, et al. Evaluation of slagging and fouling characteristics during Zhundong coal co-firing with a Si/Al dominated low rank coal[J]. Fuel, 2019, 254: 115730.
8	LIU Y Q, CHENG L M, JI J Q, et al. Ash deposition behavior in co-combusting high-alkali coal and bituminous coal in a circulating fluidized bed[J]. Applied Thermal Engineering, 2019, 149: 520-527.
9	QI X B, SONG G L, SONG W J, et al. Effects of wall temperature on slagging and ash deposition of Zhundong coal during circulating fluidized bed gasification[J]. Applied Thermal Engineering, 2016, 106: 1127-1135.
10	XIONG Z, GAO Y X, LI X, et al. A novel CO₂-water leaching method for AAEM removal from coal: suppression of PM formation and release during Zhundong coal combustion[J]. Fuel, 2020, 271: 117689.
11	YANG H R, JIN J, LIU D Y, et al. The influence of vermiculite on the ash deposition formation process of Zhundong coal[J]. Fuel, 2018, 230: 89-97.
12	NIU Y Q, GONG Y H, ZHANG X, et al. Effects of leaching and additives on the ash fusion characteristics of high-Na/Ca Zhundong coal[J]. Journal of the Energy Institute, 2019, 92(4): 1115-1122.
13	NEL M V, STRYDOM C A, SCHOBERT H H, et al. Reducing atmosphere ash fusion temperatures of a mixture of coal-associated minerals—The effect of inorganic additives and ashing temperature[J]. Fuel Processing Technology, 2014, 124: 78-86.
14	VASSILEV S V, KITANO K, TAKEDA S, et al. Influence of mineral and chemical composition of coal ashes on their fusibility[J]. Fuel Processing Technology, 1995, 45(1): 27-51.
15	ZHANG G J, REINMÖLLER M, KLINGER M, et al. Ash melting behavior and slag infiltration into alumina refractory simulating co-gasification of coal and biomass[J]. Fuel, 2015, 139: 457-465.
16	XU L L, LIU J, KANG Y, et al. Safely burning high alkali coal with kaolin additive in a pulverized fuel boiler[J]. Energy & Fuels, 2014, 28(9): 5640-5648.
17	WEI B, WANG X B, TAN H Z, et al. Effect of silicon-aluminum additives on ash fusion and ash mineral conversion of Xinjiang high-sodium coal[J]. Fuel, 2016, 181: 1224-1229.
18	DAI B Q, WU X J, DE GIROLAMO A, et al. Inhibition of lignite ash slagging and fouling upon the use of a silica-based additive in an industrial pulverised coal-fired boiler. Part 1. Changes on the properties of ash deposits along the furnace[J]. Fuel, 2015, 139: 720-732.
19	FAN Y Q, LYU Q G, ZHU Z P, et al. The impact of additives upon the slagging and fouling during Zhundong coal gasification[J]. Journal of the Energy Institute, 2020, 93(4): 1651-1665.
20	WANG Y Z, JIN J, LIU D Y, et al. Understanding ash deposition for Zhundong coal combustion in 330MW utility boiler: focusing on surface temperature effects[J]. Fuel, 2018, 216: 697-706.
21	MA J C, TIAN X, WANG C Q, et al. Fate of fuel‑nitrogen during in situ gasification chemical looping combustion of coal[J]. Fuel Processing Technology, 2021, 215: 106710.
22	ZHANG Y J, NIU S L, HAN K H, et al. Synthesis of the SrO-CaO-Al₂O₃ trimetallic oxide catalyst for transesterification to produce biodiesel[J]. Renewable Energy, 2021, 168: 981-990.
23	CHEN X D, KONG L X, BAI J, et al. Effect of Na₂O on mineral transformation of coal ash under high temperature gasification condition[J]. Journal of Fuel Chemistry and Technology, 2016, 44(3): 263-272.
24	ZHANG H X, GUO X W, ZHU Z P. Effect of temperature on gasification performance and sodium transformation of Zhundong coal[J]. Fuel, 2017, 189: 301-311.
25	LI X M, ZHI L F, SHI W J, et al. Effect of K₂O/Na₂O on fusion behavior of coal ash with high silicon and aluminum level[J]. Fuel, 2020, 265: 116964.
26	WU X J, ZHANG X, DAI B Q, et al. Ash deposition behaviours upon the combustion of low-rank coal blends in a 3MW_th pilot-scale pulverised coal-fired furnace[J]. Fuel Processing Technology, 2016, 152: 176-182.
27	WANG C A, ZHAO L, SUN R J, et al. Effects of silicon-aluminum additives on ash mineralogy, morphology, and transformation of sodium, calcium, and iron during oxy-fuel combustion of Zhundong high-alkali coal[J]. International Journal of Greenhouse Gas Control, 2019, 91: 102832.
28	ZHAO Y L, ZHANG Y M, BAO S X, et al. Effect of stone coal chemical composition on sintering behavior during roasting[J]. Industrial & Engineering Chemistry Research, 2014, 53(1): 157-163.
29	YAO Y X, JIN J, LIU D Y, et al. Evaluation of vermiculite in reducing ash deposition during the combustion of high-calcium and high-sodium Zhundong coal in a drop-tube furnace[J]. Energy & Fuels, 2016, 30(4): 3488-3494.
30	WANG Y, WANG D X, DONG C Q, et al. The behaviour and reactions of sodium containing minerals in ash melting process[J]. Journal of the Energy Institute, 2017, 90(2): 167-173.
31	SHI W J, KONG L X, BAI J, et al. Effect of CaO/Fe₂O₃ on fusion behaviors of coal ash at high temperatures[J]. Fuel Processing Technology, 2018, 181: 18-24.
32	SONG G L, YANG S B, SONG W J, et al. Release and transformation behaviors of sodium during combustion of high alkali residual carbon[J]. Applied Thermal Engineering, 2017, 122: 285-296.

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硅钙摩尔比对准东煤燃烧过程中矿物演变及灰熔融特性的影响

Influence of molar ratio of silicon to calcium on mineral evolution and ash melting characteristics during the combustion process of Zhundong coal

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