Synthesis of ZSM-22 molecular sieve and its n-dodecane hydroisomerization performance: Effect of template agent and dynamic crystallization

doi:10.16085/j.issn.1000-6613.2023-0211

Abstract

Abstract:

ZSM-22 zeolites with different morphologies and aggregation states were synthesized by using diethylamine (DEA) or 1,6-hexadiamine (DAH) as templates under static or dynamic conditions, respectively, and characterized by XRD, SEM, EDS, TEM, NH₃-TPD and N₂adsorption/desorption. The bifunctional catalyst was prepared by mechanical mixing Pt loaded Al₂O₃ with ZSM-22, and its n-dodecane hydroisomerization performance was investigated. The results showed that template agent and dynamic crystallization could change the morphology and aggregation state of ZSM-22 molecular sieve, and affect its acidity, specific surface area and hydroisomerization activity. ZSM-22 synthesized with diethylamine as template and after 72h of static crystallization had the best catalytic performance. At 310℃, the selectivity of isomerization of n-dodecane reached 90% when the conversion of isomerization was 66%. However, the template agent and the dynamic crystallization conditions had little effect on the distribution of the single branched isomer in product. The isomer products were dominated by 2-methylundecane with the branched chain near the end, and the selectivity of 2-methyl isomer decreased with the increase of reaction temperature.

Key words: catalyst, zeolite, molecular sieves, ZSM-22, n-dodecane, hydroisomerization

摘要：

以二乙胺（DEA）或1,6-己二胺（DAH）为模板剂，分别在静态或动态条件下合成具有不同形貌和聚集状态的ZSM-22分子筛，采用XRD、SEM、EDS、TEM、NH₃-TPD及N₂吸附/脱附表征手段对其进行表征分析。并负载Pt在Al₂O₃上和ZSM-22机械混合制备双功能催化剂，考察其正十二烷的临氢异构化反应性能。结果表明，模板剂和动态晶化会改变ZSM-22分子筛的形貌及聚集状态，并且会影响其酸性、比表面积和临氢异构活性。其中，以二乙胺为模板剂，静态晶化72h合成的ZSM-22具有最优的催化性能，在310℃反应温度下，正十二烷异构化转化率为66%时，异构十二烷的选择性达到90%。但是，模板剂及动态晶化条件对单支链异构体的产物分布影响较小，异构体产物以支链靠近端位的2-甲基十一烷为主，且随着反应温度升高，2-甲基异构体选择性明显降低。

关键词: 催化剂, 沸石, 分子筛, ZSM-22, 正十二烷, 临氢异构化

CLC Number:

TQ09

ZHANG Haipeng, WANG Shuzhen, MA Mengxi, ZHANG Wei, XIANG Jiangnan, WANG Yuting, WANG Yan, FAN Binbin, ZHENG Jiajun, LI Ruifeng. Synthesis of ZSM-22 molecular sieve and its n-dodecane hydroisomerization performance: Effect of template agent and dynamic crystallization[J]. Chemical Industry and Engineering Progress, 2024, 43(1): 414-421.

张海鹏, 王树振, 马梦茜, 张巍, 向江南, 王玉婷, 王琰, 范彬彬, 郑家军, 李瑞丰. ZSM-22分子筛合成及其正十二烷烃临氢异构化性能：模板剂和动态晶化的影响[J]. 化工进展, 2024, 43(1): 414-421.

Figures/Tables 12

References 30

1	安军信. 国内外润滑油市场现状及发展趋势分析[J]. 合成润滑材料, 2021, 48(1): 42-47.
	AN Junxin. Analysis on current situation and developing trend of domestic and foreign lubricants market[J]. Synthetic Lubricants, 2021, 48(1): 42-47.
2	高新伟, 张智川, 韩宇凯, 等. 全国统一大市场背景下我国润滑油基础油标准化难点及对策[J]. 中国石油大学学报(社会科学版), 2022, 38(3): 11-16.
	GAO Xinwei, ZHANG Zhichuan, HAN Yukai, et al. Difficulties and countermeasures in the standardization of lubricant base oil under the background of a national unified market[J]. Journal of China University of Petroleum (Edition of Social Sciences), 2022, 38(3): 11-16.
3	李海华. 我国资源结构及煤液化发展现状[J]. 煤炭技术, 2012, 31(1): 233-234.
	LI Haihua. Resource structure and current development status of coal liquefaction in China[J]. Coal Technology, 2012, 31(1): 233-234.
4	KHODAKOV A Y, CHU W, PASCAL F. Advances in the development of novel cobalt fischer-tropsch catalysts for synthesis of long-chain hydrocarbons and clean fuels[J]. Chemical Reviews, 2007, 107(5): 1692-1744.
5	CALEMMA V, GAMBARO C, PARKER W O, et al. Middle distillates from hydrocracking of FT waxes: Composition, characteristics and emission properties[J]. Catalysis Today, 2010, 149(1/2): 40-46.
6	BOUCHY C, HASTOY G, GUILLON E, et al. Fischer-tropsch waxes upgrading via hydrocracking and selective hydroisomerization[J]. Oil & Gas Science and Technology-Revue De L’IFP, 2009, 64(1): 91-112.
7	MARTENS J A, VANBUTSELE G, JACOBS P A, et al. Evidences for pore mouth and key-lock catalysis in hydroisomerization of long n-alkanes over 10-ring tubular pore bifunctional zeolites[J]. Catalysis Today, 2001, 65(2/3/4): 111-116.
8	BAUER F, FICHT K, BERTMER M, et al. Hydroisomerization of long-chain paraffins over nano-sized bimetallic Pt-Pd/H-beta catalysts[J]. Catalysis Science & Technology, 2014, 4(11): 4045-4054.
9	ROLDÁN R, BEALE A M, SÁNCHEZ-SÁNCHEZ M, et al. Effect of the impregnation order on the nature of metal particles of bi-functional Pt/Pd-supported zeolite beta materials and on their catalytic activity for the hydroisomerization of alkanes[J]. Journal of Catalysis, 2008, 254(1): 12-26.
10	LEE Joeng-Kyu, RHEE Hyun-Ku. Sulfur tolerance of zeolite beta-supported Pd-Pt catalysts for the isomerization of n-hexane[J]. Journal of Catalysis, 1998, 177(2): 208-216.
11	Tiong SIE S. Acid-catalyzed cracking of paraffinic hydrocarbons. 3. Evidence for the protonated cyclopropane mechanism from hydrocracking/hydroisomerization experiments[J]. Industrial & Engineering Chemistry Research, 1993, 32(3): 403-408.
12	LIU Linlin, ZHANG Mingwei, WANG Li, et al. Modulating acid site distribution in MTT channels for controllable hydroisomerization of long-chain n-alkanes[J]. Fuel Processing Technology, 2023, 241: 107605.
13	PARMAR S, PANT K K, JOHN M, et al. Hydroisomerization of n-hexadecane over Pt/ZSM-22 framework: Effect of divalent cation exchange[J]. Journal of Molecular Catalysis A: Chemical, 2015, 404/405: 47-56.
14	LIU Suyao, REN Jie, ZHU Shujin, et al. Synthesis and characterization of the Fe-substituted ZSM-22 zeolite catalyst with high n-dodecane isomerization performance[J]. Journal of Catalysis, 2015, 330: 485-496.
15	DREWS T O, TSAPATSIS M. Progress in manipulating zeolite morphology and related applications[J]. Current Opinion in Colloid & Interface Science, 2005, 10(5/6): 233-238.
16	HU Linyan, ZHANG Zekai, XIE Sujuan, et al. Effect of grain size of zeolite Y on its catalytic performance in olefin alkylation thiophenic sulfur process[J]. Catalysis Communications, 2009, 10(6): 900-904.
17	JAMIL A K, MURAZA O. Facile control of nanosized ZSM-22 crystals using dynamic crystallization technique[J]. Microporous and Mesoporous Materials, 2016, 227: 16-22.
18	TREACY M M J, HIGGINS J B. Ferrierite[M]//Collection of simulated XRD powder patterns for zeolites. Amsterdam: Elsevier, 2007: 178-179.
19	SOUSA L V, SILVA A O S, SILVA B J B, et al. Fast synthesis of ZSM-22 zeolite by the seed-assisted method of crystallization with methanol[J]. Microporous and Mesoporous Materials, 2017, 254: 192-200.
20	WANG Bingchun, TIAN Zhijian, LI Peng, et al. Synthesis of ZSM-23/ZSM-22 intergrowth zeolite with a novel dual-template strategy[J]. Materials Research Bulletin, 2009, 44(12): 2258-2261.
21	LIU Suyao, REN Jie, ZHANG Huaike, et al. Synthesis, characterization and isomerization performance of micro/mesoporous materials based on H-ZSM-22 zeolite[J]. Journal of Catalysis, 2016, 335: 11-23.
22	王宏浩, 刘粟侥, 张怀科, 等. ZSM-22分子筛的合成、表征及烷基化性能研究[J]. 燃料化学学报, 2016, 44(8): 1010-1016.
	WANG Honghao, LIU Suyao, ZHANG Huaike, et al. Synthesis and characterization of ZSM-22 zeolites and their catalytic performance in alkylation reaction[J]. Journal of Fuel Chemistry and Technology, 2016, 44(8): 1010-1016.
23	LIU H Y, EHSAN K. Investigation the synthesis of nano-SAPO-34 catalyst prepared by different templates for MTO process[J]. Catalysis Letters, 2021, 151(3): 787-802.
24	王琰, 刘伟, 李赛, 等. Pt负载位置对双功能催化剂正十二烷加氢异构化性能影响[J]. 石油学报(石油加工), 2021, 37(6): 1338-1345.
	WANG Yan, LIU Wei, LI Sai, et al. Influence of Pt position on the performance of bifunctional catalysts for n-dodecane hydroisomerization[J]. Acta Petrolei Sinica (Petroleum Processing Section), 2021, 37(6): 1338-1345.
25	ZECEVIC J, VANBUTSELE G, DE JONG K P, et al. Nanoscale intimacy in bifunctional catalysts for selective conversion of hydrocarbons[J]. Nature, 2015, 528(7581): 245-248.
26	SAMAD J E, BLANCHARD J, SAYAG C, et al. The controlled synthesis of metal-acid bifunctional catalysts: The effect of metal: Acid ratio and metal-acid proximity in Pt silica-alumina catalysts for n-heptane isomerization[J]. Journal of Catalysis, 2016, 342: 203-212.
27	LI C L, NOVARO O, MUÑOZ E, et al. Coke deactivation of Pd/H-mordenite catalysts used for C₅/C₆ hydroisomerization[J]. Applied Catalysis A: General, 2000, 199(2): 211-220.
28	王富民, 辛峰, 廖晖, 等. 异丙苯裂化催化剂ASTRA-MB¹积炭失活机理[J]. 石油学报(石油加工), 2002, 18(5): 28-33.
	WANG Fumin, XIN Feng, LIAO Hui, et al. Mechanism of ASTRA-MB¹ catalyst deactivation for cumene cracking due to coking[J]. Acta Petrolei Sinica (Petroleum Processing Section), 2002, 18(5): 28-33.
29	CLAUDE M C, MARTENS J A. Monomethyl-branching of long n-alkanes in the range from decane to tetracosane on Pt/H-ZSM-22 bifunctional catalyst[J]. Journal of Catalysis, 2000, 190(1): 39-48.
30	WANG Yan, LIU Wei, ZHANG Wei, et al. Comparison of n-dodecane hydroisomerization performance over Pt supported ZSM-48 and ZSM-22[J]. Catalysis Letters, 2021, 151(12): 3492-3500.

样品	w_atom/%		硅铝比
样品	Si	Al	硅铝比
D-ZSM-22	96.4	3.6	26.8
C-ZSM-22	95.7	4.3	22.3
J-ZSM-22	96.1	3.9	24.6
Z-ZSM-22	96.2	3.8	25.3

样品	w_atom/%		硅铝比
样品	Si	Al	硅铝比
D-ZSM-22	96.4	3.6	26.8
C-ZSM-22	95.7	4.3	22.3
J-ZSM-22	96.1	3.9	24.6
Z-ZSM-22	96.2	3.8	25.3

样品	弱酸量/μmol·g^-1	强酸量/μmol·g^-1	总酸量/μmol·g^-1
D-ZSM-22	181	231	412
C-ZSM-22	185	245	430
J-ZSM-22	196	250	446
Z-ZSM-22	197	253	450

样品	弱酸量/μmol·g^-1	强酸量/μmol·g^-1	总酸量/μmol·g^-1
D-ZSM-22	181	231	412
C-ZSM-22	185	245	430
J-ZSM-22	196	250	446
Z-ZSM-22	197	253	450

样品	总比表面积/m²·g^-1	微孔表面积/m²·g^-1	介孔表面积/m²·g^-1	总孔体积/cm³·g^-1	微孔体积/cm³·g^-1	介孔体积/cm³·g^-1
D-ZSM-22	247	230	17	0.12	0.09	0.03
C-ZSM-22	292	246	46	0.17	0.10	0.07
J-ZSM-22	278	224	54	0.19	0.09	0.10
Z-ZSM-22	279	220	59	0.21	0.09	0.12