Effect of sodium and mineral types on distribution of tar and BTEXN under high alkali coal fast pyrolysis

doi:10.11949/0438-1157.20200666

Abstract

Abstract:

Light aromatic hydrocarbons (BTEXN) such as benzene, toluene, ethylbenzene, xylene and naphthalene are used as high-value chemical raw materials and are widely used in industry. Refining of coal retorting tar is one of the important production methods of BTEXN. In this paper, we carry out fast pyrolysis research on Xinjiang high-alkali coal in order to expand the applications of Xinjiang high-alkali coal in chemical industry. Two typical high-alkali coals from Xinjiang which called Hongshaquan and Jiangjunmiao, which were prepeared through the two pretreatment methods of sequential extraction and external addition of sodium, were used to semi-quantitatively study the effect of sodium form and content in high alkali coal, as well as the types of mineral components on the fast pyrolysis tar and BTEXN precipitation characteristics by Py-GC/MS. The results show that the inherent minerals in both high-alkali coals could increase the precipitation of tar and BTEXN for which the water-soluble(Na, Ca) minerals played a key role. Endogenous water-soluble minerals and ammonium acetate-soluble minerals which mainly based on sodium and calcium both increased the precipitation of Hongshaquan coal tar by 22% and 55%. However, the addition of water-soluble NaCl and ammonium acetate-soluble CH₃COONa from external sources reduced the precipitation of Jiangjunmiao coal tar. Water-soluble minerals,1.0%(mass) NaCl and CH₃COONa respectively increased the precipitation of BTEXN in coal tar by 45%,42% and 62%. However, the ammonium acetate soluble substance and low content (0.4%(mass)) Na will inhibit the precipitation of BTEXN.

Key words: BTEXN, high alkali coal, sodium form, fast pyrolysis, Py-GC/MS

摘要：

轻质芳烃（BTEXN）如苯、甲苯、乙苯、二甲苯和萘作为高价值化学原料，在工业中具有广泛应用。煤干馏焦油的精制是BTEXN重要生产方法之一。本文分别选用红沙泉和将军庙两种典型新疆高碱煤，通过逐级萃取及外源添加Na两种预处理方式，利用Py-GC/MS半定量研究了高碱煤中钠形态和含量，以及矿物组分类型对煤快速热解焦油及BTEXN产物分布的影响。结果表明，两种高碱煤中固有矿物质均可提高焦油及BTEXN析出量，水溶性矿物质（Na）对此起关键作用。内源性水溶性矿物及醋酸铵溶性矿物使红沙泉煤焦油析出量提高22%和55%；而外源添加的水溶性NaCl和醋酸铵溶性CH₃COONa降低了将军庙煤焦油析出量。水溶性矿物及1.0%（质量）的NaCl和CH₃COONa分别使煤焦油中的BTEXN析出量提高45%、42%和62%，醋酸铵溶性物质及低含量[0.4%(质量)]Na则会抑制BTEXN的析出。

关键词: BTEXN, 高碱煤, 钠形态, 快速热解, Py-GC/MS

CLC Number:

WEI Lihong, FAN Yu, FANG Fan, GUO Liangzhen, CHEN Yong, YANG Tianhua. Effect of sodium and mineral types on distribution of tar and BTEXN under high alkali coal fast pyrolysis[J]. CIESC Journal, 2021, 72(3): 1702-1711.

魏砾宏, 樊雨, 房凡, 郭良振, 陈勇, 杨天华. Na及矿物类型对高碱煤快速热解焦油及BTEXN产物分配的影响[J]. 化工学报, 2021, 72(3): 1702-1711.

Figures/Tables 12

References 29

1	Bell D, Towler B, Fan M. Coal Gasification and Its Applications[M]. Great Britain: Elsevier Inc.,2010.
2	Granda M, Blanco C, Alvarez P, et al. Chemicals from coal coking[J]. Chemical Reviews,2013,114(3): 1608-1636.
3	国家统计局.2019年中国统计年鉴[M]. 北京:中国统计出版社, 2019.
	National Bureau of Statistics. China Statistical Yearbook 2019 [M]. Beijing: China Statistics Press, 2019.
4	Meng J, Wang Z, Ma Y, et al. Hydrocracking of low-temperature coal tar over NiMo/Beta-KIT-6 catalyst to produce gasoline oil[J]. Fuel Process Technol, 2017, 165:62-71.
5	Rezaei P S, Shafaghat H, Daud W M A W. Production of green aromatics and olefins by catalytic cracking of oxygenate compounds derived from biomass pyrolysis: a review[J]. Appl. Catal. A Gen., 2014, 469 (17): 490-511.
6	Han J Z, Liu X X, Yue J R, et al. Catalytic upgrading of in situ coal pyrolysis tar over Ni-char catalyst with different additives[J]. Energy Fuel, 2014, 28 (8): 4934-4941.
7	Xu Z, Liang L T, Zhang Q, et al. A study on catalytic depolymerization of a typical perhydrous coal for improving tar yield[J]. J. Anal. Appl. Pyrolysis, 2019, 138: 242-248.
8	Huang Y, Wang N B, Liu Q X, et al. Co-pyrolysis of bituminous coal and biomass in a pressured fluidized bed[J]. Chinese J. Chemeng., 2019, 27(7): 1666-1673.
9	Li Y, Amin M N, Lu X. Pyrolysis and catalytic upgrading of low-rank coal using a NiO/MgO-Al₂O₃ catalyst[J]. Chem. Eng. Sci., 2016, 155: 194-200.
10	Yan L J, Bai Y H, Kong X J, et al. Effects of alkali and alkaline earth metals on the formation of light aromatic hydrocarbons during coal pyrolysis[J]. J. Anal. Appl. Pyrolysis, 2016, 122: 169-174.
11	Li G L, Yan L J, Zhao R F, et al. Improving aromatic hydrocarbons yield from coal pyrolysis volatile products over HZSM-5 and Mo-modified HZSM-5[J]. Fuel, 2014, 130: 154-159.
12	Jiang Y, Zong P J, Tian B, et al. Pyrolysis behaviors and product distribution of Shenmu coal at high heatingrate: a study using TG-FTIR and Py-GC/MS[J]. Energ. Convers. Manage., 2019, 179: 72-80.
13	Liu Y J,Yan L J,Bai Y H,et al. Catalytic upgrading of volatile from coal pyrolysis over faujasite zeolites[J]. J. Anal. Appl. Pyrolysis,2018,132:184-189.
14	He Y Y,Yan L J,Liu Y J, et al. Effect of SiO₂/Al₂O₃ ratios of HZSM-5 zeolites on the formation of light aromatics during lignite pyrolysis[J]. Fuel Process Technol., 2019, 188: 70-78.
15	钟梅,马凤云. 不同气氛下煤连续热解产物的分配规律及产品品质分析[J]. 燃料化学学报, 2013, 41(12): 1427-1436.
	Zhong M,Ma F Y. Distribution law and product quality analysis of continuous pyrolysis products of coal under different atmospheres[J]. J. Fuel Chem. Technol., 2013, 41(12): 1427-1436.
16	He L, Hui H L, Lia S G, et al. Production of light aromatic hydrocarbons by catalytic cracking of coal pyrolysis vapors over natural iron ores[J]. Fuel, 2018, 216: 227-232.
17	Richard F S. Catalytic pyrolysis of biomass for biofuels production[J]. Fuel Process Technol., 2010, 91(1): 25-32.
18	宋维健, 宋国良, 齐晓宾, 等. 不同预处理方法对准东高碱煤中碱金属含量测定的影响[J]. 燃料化学学报,2016, 44(2): 162-167.
	Song W J, Song G L, Qi X B, et al. Effect of pretreatment methods on the determination of alkali metal content in high alkali metal Zhundong coal[J]. J. Fuel Chem. Technol., 2016, 44(2): 162-167.
19	Liu Y Q, Cheng L M, Zhao Y G, et al. Transformation behavior of alkali metals in high-alkali coals [J]. Fuel Process Technol., 2018, 169: 288-294.
20	Wang C A, Liu T H, Jin X, et al. Effect of water washing on reactivities and NO_x emission of Zhundong coals[J]. J. Energy Inst., 2016, 89: 636-647.
21	Ding C L, Qiang X, Zheng W, et al. Transformation of alkali and alkaline earth metals in Zhundong coal during pyrolysis in an entrained flow bed reactor[J]. J. Anal. Appl. Pyrolysis, 2019, 142:104661.
22	Jie D, Fan L, Ke C X. Study on the source of polycyclic aromatic hydrocarbons (PAHs) during coal pyrolysis by Py-GC-MS[J]. Journal of Hazardous Materials, 2012, 243: 80-85.
23	马亚亚, 马凤云, 莫文龙, 等. 酸洗脱灰处理对新疆和丰低阶煤结构和萃取性能的影响[J].燃料化学学报,2019, 47(6): 649-660.
	Ma Y Y, Ma F Y, Mo W L,et al. Effect of acid eluting ash treatment on the structure and extraction performance of Xinjiang Hefeng low rank coal[J]. J. Fuel Chem. Technol., 2019, 47(6) : 649-660.
24	Peng L, Lun J Y, Yan L, et al. Catalytic upgrading of coal pyrolysis gaseous tar over hierarchical Y-type zeolites synthesized using microwave hydrothermal method[J]. Ind. Eng. Chem. Res., 2019, 58(47): 21817-21826.
25	Zhao Y L, Zhao P Z, Bo Z, et al. Catalytic fast pyrolysis of bamboo over micro-mesoporous composite molecular sieves using Py-GC/MS[J]. Energy Technol., 2017, 6(4): 728-736.
26	Li C Z, Sathe C, Kershaw J R, et al. Fates and roles of alkali and alkaline earth metals during the pyrolysis of a Victorian brown coal[J]. Fuel, 2000, 79(3/4): 427-438.
27	刘辉, 赵登, 姜雷宵, 等.羧酸钠对准东煤热解过程的影响[J]. 化工学报, 2016, 67( 11) : 4795-4801.
	Liu H, Zhao D, Jiang L X, et al. Effect of sodium carboxylate on pyrolysis of Zhundong coal( H-form coal)[J] . CIESC Journal, 2016, 67( 11) : 4795-4801.
28	Lai C K, Chen S, Longwell P, et al. Thermal reactions of m-cresol over calcium oxide between 350 and 600℃[J]. Fuel, 1987, 66 (4): 525-531.
29	Zhou Y, Li G, Jin L J, et al. In situ analysis of catalytic effect of calcium nitrate on Shenmu coal pyrolysis with pyrolysis vacuum ultraviolet photoionization mass spectrometry[J]. Energy & Fuels, 2018, 32(2): 1061-1069.

项目	将军庙煤	红沙泉煤
工业分析/%(mass, d)
A	7.43	8.80
V	36.82	35.99
FC^①	55.75	55.21
元素分析/%(mass, d)
C	74.91	72.09
H	3.76	4.20
O^②	12.56	13.44
N	0.78	0.98
S	0.56	0.49
灰分分析/%(mass)
SiO₂	26.52	39.77
Fe₂O₃	15.61	13.93
TiO₂	0.48	0.95
Al₂O₃	8.71	16.73
CaO	15.95	8.89
MgO	9.55	5.55
K₂O	0.52	0.61
Na₂O	7.66	5.34
P₂O₅	0.11	0.30
热值/（MJ/kg）	23.640	24.308
H/C	0.60	0.69
O/C	0.12	0.14

项目	将军庙煤	红沙泉煤
工业分析/%(mass, d)
A	7.43	8.80
V	36.82	35.99
FC^①	55.75	55.21
元素分析/%(mass, d)
C	74.91	72.09
H	3.76	4.20
O^②	12.56	13.44
N	0.78	0.98
S	0.56	0.49
灰分分析/%(mass)
SiO₂	26.52	39.77
Fe₂O₃	15.61	13.93
TiO₂	0.48	0.95
Al₂O₃	8.71	16.73
CaO	15.95	8.89
MgO	9.55	5.55
K₂O	0.52	0.61
Na₂O	7.66	5.34
P₂O₅	0.11	0.30
热值/（MJ/kg）	23.640	24.308
H/C	0.60	0.69
O/C	0.12	0.14

金属	含量/(μg/g)
金属	水溶性矿物	醋酸铵溶性矿物	盐酸溶性矿物	不溶性矿物
K	283	161	82	859
Ca	873	6681	7472	2365
Na	3113	734	145	277
Mg	855	1926	804	782

金属	含量/(μg/g)
金属	水溶性矿物	醋酸铵溶性矿物	盐酸溶性矿物	不溶性矿物
K	283	161	82	859
Ca	873	6681	7472	2365
Na	3113	734	145	277
Mg	855	1926	804	782

样品	含量/(μg/g)
0.4DNa	1586
1DNa	3966
0.4DAc	1121
1DAc	2802