Reaction kinetics of naphthalene cracking into small molecule gas in a micro fluidized bed

doi:10.11949/0438-1157.20201738

Abstract

Abstract:

Gasification is one of the effective ways for high-value utilization of coal, biomass and other carbon-containing fuels. To investigate the reaction characteristics of tar during gasification, naphthalene was selected as the tar model compound and converted in a micro fluidized bed by using fluid catalytic cracking (FCC) catalyst and lignite coke as contact cracking carrier. The cracking kinetics of naphthalene in terms of CH₄ and H₂ generation were calculated by Friedman method and integral method respectively. The results show that both FCC catalyst and lignite coke had obvious catalytic effect on naphthalene. When lignite coke was used for naphthalene cracking, the overall reaction activation energy was lower than that of FCC catalyst. The catalytic cracking of naphthalene over FCC catalyst was close to three-dimensional diffusion (spherical symmetry) and nucleation and growth (n=2/3) models, while the three-dimensional diffusion (cylindrical symmetry) and contraction geometry (cylindrical symmetry) models had a good fitting degree for naphthalene cracking using lignite coke.

Key words: micro fluidized bed, naphthalene, catalytic cracking, reaction kinetics

摘要：

气化是煤、生物质以及其他含碳燃料高值化利用的有效途径之一。为了考察气化过程中焦油的反应转化特性，选取萘作为焦油模型化合物，以流化催化裂化（fluid catalytic cracking，FCC）催化剂及褐煤热解焦作为接触裂解载体，利用微型流化床考察流化条件下萘催化裂解反应规律，并采用Friedman法和积分法计算萘裂解生成CH₄和H₂等典型气体组分的动力学参数。结果表明，FCC催化剂与褐煤焦均对萘裂解有明显的催化效果，褐煤焦用于萘裂解的反应活化能整体数值低于FCC催化剂。FCC催化剂裂解萘生成H₂符合三维扩散（球形对称）模型，生成CH₄符合成核与生长（n=2/3）模型。相应地，褐煤焦裂解萘反应生成H₂和CH₄分别采用收缩几何形状（圆柱形对称）和三维扩散（圆柱形对称）具有较好的拟合度。

关键词: 微型流化床, 萘, 催化裂解, 反应动力学

CLC Number:

TQ 546

ZHANG Yuming, JI Dexin, ZHU Hanwen, WAN Lifeng, ZHANG Wei, WEN Hongyan, YUE Junrong. Reaction kinetics of naphthalene cracking into small molecule gas in a micro fluidized bed[J]. CIESC Journal, 2021, 72(5): 2604-2615.

张玉明, 纪德馨, 朱翰文, 万利锋, 张炜, 温宏炎, 岳君容. 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.

Figures/Tables 14

References 33

1	Zhang S, Song Y, Song Y C, et al. An advanced biomass gasification technology with integrated catalytic hot gas cleaning(Ⅲ): Effects of inorganic species in char on the reforming of tars from wood and agricultural wastes[J]. Fuel, 2016, 183: 177-184.
2	Guan G Q, Kaewpanha M, Hao X G, et al. Catalytic steam reforming of biomass tar: prospects and challenges[J]. Renewable and Sustainable Energy Reviews, 2016, 58: 450-461.
3	Morin M, Nitsch X, Pécate S, et al. Tar conversion over olivine and sand in a fluidized bed reactor using toluene as model compound[J]. Fuel, 2017, 209: 25-34.
4	Zhang S, Chen Z D, Zhang H Y, et al. The catalytic reforming of tar from pyrolysis and gasification of brown coal: effects of parental carbon materials on the performance of char catalysts[J]. Fuel Processing Technology, 2018, 174: 142-148.
5	吴悠, 赵立欣, 孟海波, 等. 生物质热解焦油脱除方法研究进展[J]. 化工环保, 2016, 36(1): 17-21.
	Wu Y, Zhao L X, Meng H B, et al. Research progresses on removal of tar in biomass pyrolysis[J]. Environmental Protection of Chemical Industry, 2016, 36(1): 17-21.
6	Phuphuakrat T, Namioka T, Yoshikawa K. Absorptive removal of biomass tar using water and oily materials[J]. Bioresource Technology, 2011, 102(2): 543-549.
7	吴娟, 陈海军, 朱跃钊, 等. 基于回收理念的生物质燃气焦油脱除研究进展[J]. 化工进展, 2013, 32(9): 2099-2105, 2111.
	Wu J, Chen H J, Zhu Y Z, et al. Biomass producer gas tar removal technology based on recovery idea[J]. Chemical Industry and Engineering Progress, 2013, 32(9): 2099-2105, 2111.
8	赵善辉, 罗永浩, 苏毅, 等. 部分氧化对焦油模型化合物苯酚转化的机理[J]. 化工学报, 2013, 64(10): 3790-3796.
	Zhao S H, Luo Y H, Su Y, et al. Reaction mechanism for partial oxidation of biomass tar[J]. CIESC Journal, 2013, 64(10): 3790-3796.
9	Zhang S, Asadullah M, Dong L, et al. An advanced biomass gasification technology with integrated catalytic hot gas cleaning(Ⅱ): Tar reforming using char as a catalyst or as a catalyst support[J]. Fuel, 2013, 112: 646-653.
10	Xu C, Donald J, Byambajav E, et al. Recent advances in catalysts for hot-gas removal of tar and NH₃ from biomass gasification[J]. Fuel, 2010, 89(8): 1784-1795.
11	Quitete C P B, Souza M M V M. Application of Brazilian dolomites and mixed oxides as catalysts in tar removal system[J]. Applied Catalysis A: General, 2017, 536: 1-8.
12	Florin N H, Harris A T. Enhanced hydrogen production from biomass with in situ carbon dioxide capture using calcium oxide sorbents[J]. Chemical Engineering Science, 2008, 63(2): 287-316.
13	de Andrés J M, Narros A, Rodríguez M E. Behaviour of dolomite, olivine and alumina as primary catalysts in air-steam gasification of sewage sludge[J]. Fuel, 2011, 90(2): 521-527.
14	刘殊远, 汪印, 武荣成, 等. 热态半焦和冷态半焦催化裂解煤焦油研究[J]. 燃料化学学报, 2013, 41(9): 1041-1049.
	Liu S Y, Wang Y, Wu R C, et al. Research on coal tar catalytic cracking over hot in situ chars[J]. Journal of Fuel Chemistry and Technology, 2013, 41(9): 1041-1049.
15	王芳, 曾玺, 孙延林, 等. 两段流化床中半焦催化脱除焦油特性[J]. 化工学报, 2017, 68(10): 3762-3769.
	Wang F, Zeng X, Sun Y L, et al. Characteristics of char catalytic reforming of tar in two-stage fluidized bed[J]. CIESC Journal, 2017, 68(10): 3762-3769.
16	Zhang L X, Matsuhara T, Kudo S, et al. Rapid pyrolysis of brown coal in a drop-tube reactor with co-feeding of char as a promoter of in situ tar reforming[J]. Fuel, 2013, 112: 681-686.
17	Wang F J, Zhang S, Chen Z D, et al. Tar reforming using char as catalyst during pyrolysis and gasification of Shengli brown coal[J]. Journal of Analytical and Applied Pyrolysis, 2014, 105: 269-275.
18	Sun Q S, Yu S, Wang F C, et al. Decomposition and gasification of pyrolysis volatiles from pine wood through a bed of hot char[J]. Fuel, 2011, 90(3): 1041-1048.
19	Abu El-Rub Z, Bramer E A, Brem G. Experimental comparison of biomass chars with other catalysts for tar reduction[J]. Fuel, 2008, 87(10/11): 2243-2252.
20	Bangala D N, Abatzoglou N, Martin J P, et al. Catalytic gas conditioning: application to biomass and waste gasification[J]. Industrial & Engineering Chemistry Research, 1997, 36(10): 4184-4192.
21	Milne T A, Evans R J, Abatzaglou N. Biomass gasifier “Tars”: their nature, formation, and conversion[R]. Office of Scientific and Technical Information (OSTI), 1998.
22	Fuentes-Cano D, Gómez-Barea A, Nilsson S, et al. Decomposition kinetics of model tar compounds over chars with different internal structure to model hot tar removal in biomass gasification[J]. Chemical Engineering Journal, 2013, 228: 1223-1233.
23	Jess A. Mechanisms and kinetics of thermal reactions of aromatic hydrocarbons from pyrolysis of solid fuels[J]. Fuel, 1996, 75(12): 1441-1448.
24	Devi L, Craje M, Thüne P, et al. Olivine as tar removal catalyst for biomass gasifiers: catalyst characterization[J]. Applied Catalysis A: General, 2005, 294(1): 68-79.
25	de Lasa H, Salaices E, Mazumder J, et al. Catalytic steam gasification of biomass: catalysts, thermodynamics and kinetics[J]. Chemical Reviews, 2011, 111(9): 5404-5433.
26	Buentello-Montoya D A, Zhang X, Li J. The use of gasification solid products as catalysts for tar reforming[J]. Renewable and Sustainable Energy Reviews, 2019, 107: 399-412.
27	Vassilev S V, Baxter D, Andersen L K, et al. An overview of the composition and application of biomass ash(2): Potential utilisation, technological and ecological advantages and challenges[J]. Fuel, 2013, 105: 19-39.
28	Wornat M J, Nelson P F. Effects of ion-exchanged calcium on brown coal tar composition as determined by Fourier transform infrared spectroscopy[J]. Energy & Fuels, 1992, 6(2): 136-142.
29	Fuentes-Cano D, Parrillo F, Ruoppolo G, et al. The influence of the char internal structure and composition on heterogeneous conversion of naphthalene[J]. Fuel Processing Technology, 2018, 172: 125-132.
30	姜微微, 郝文倩, 刘雪景, 等. 微型流化床内菱镁矿轻烧反应特性及动力学[J]. 化工学报, 2019, 70(8): 2928-2937.
	Jiang W W, Hao W Q, Liu X J, et al. Characteristic and kinetics of light calcination of magnesite in micro fluidized bed reaction analyzer[J]. CIESC Journal, 2019, 70(8): 2928-2937.
31	Valderrama Rios M L, González A M, Lora E E S, et al. Reduction of tar generated during biomass gasification: a review[J]. Biomass and Bioenergy, 2018, 108: 345-370.
32	Shen Y F, Yoshikawa K. Recent progresses in catalytic tar elimination during biomass gasification or pyrolysis—a review[J]. Renewable and Sustainable Energy Reviews, 2013, 21: 371-392.
33	Gai C, Dong Y P, Lv Z C, et al. Pyrolysis behavior and kinetic study of phenol as tar model compound in micro fluidized bed reactor[J]. International Journal of Hydrogen Energy, 2015, 40(25): 7956-7964.

样品	工业分析/%(质量分数)				元素分析/%(质量分数)
样品	V_ad	M_ad	A_ad	FC_ad*	N_d	C_d	H_d	S_d	O_d*
LC	4.12	2.92	25.59	67.37	0.94	69.32	1.49	0.80	1.09

样品	工业分析/%(质量分数)				元素分析/%(质量分数)
样品	V_ad	M_ad	A_ad	FC_ad*	N_d	C_d	H_d	S_d	O_d*
LC	4.12	2.92	25.59	67.37	0.94	69.32	1.49	0.80	1.09

LC ash/%（质量分数）
TiO₂	MgO	Al₂O₃	SiO₂	SO₃	K₂O	CaO	Fe₂O₃	Others
1.19	3.94	8.56	12.63	31.65	0.54	34.46	6.52	0.51
FCC-C/%（质量分数）
V₂O₅	P₂O₅	Al₂O₃	SiO₂	Na₂O	K₂O	NiO	Fe₂O₃	Others
1.09	1.38	47.87	47.34	0.36	0.20	0.52	0.51	0.73

LC ash/%（质量分数）
TiO₂	MgO	Al₂O₃	SiO₂	SO₃	K₂O	CaO	Fe₂O₃	Others
1.19	3.94	8.56	12.63	31.65	0.54	34.46	6.52	0.51
FCC-C/%（质量分数）
V₂O₅	P₂O₅	Al₂O₃	SiO₂	Na₂O	K₂O	NiO	Fe₂O₃	Others
1.09	1.38	47.87	47.34	0.36	0.20	0.52	0.51	0.73

样品	比表面积/(m²/g)			孔体积/(cm³/g)			平均孔径D_a/nm
样品	A_total	A_micro	A_meso	V_total	V_mico	V_meso	平均孔径D_a/nm
LC	214.0	175.5	38.5	0.5319	0.1043	0.4276	9.94
FCC-C	106.8	64.6	42.2	0.5716	0.0432	0.5329	24.97