Dimethylether production on zeolite catalysts activated by Cl-, F- and/or ultrasonication
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Abstract: The chlorinated and fluorinated zeolite catalysts were prepared by the impregnation of zeolites (H-ZSM-5, H-MOR or H-Y) using two halogen precursors (ammonium chloride and ammonium fluoride) in this study. The influence of ultrasonic irradiation was evaluated for optimizing both halogen precursors for production of dimethylether (DME) via methanol dehydration in a fixed bed reactor. The catalysts were characterized by SEM, XRD, BET and NH3-TPD. The reaction conditions were temperatures from 100 to 300 ℃ and a WHSV =15.9 h-1. All halogenated catalysts show higher catalytic activities at all reaction temperatures studied. However, the halogenated zeolite catalysts prepared under ultrasonic irradiation show higher performance for DME formation. The chlorinated zeolite catalysts show higher activity and selectivity for DME production than the respective fluorinated versions.
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Key words:
- ultrasonication /
- DME /
- zeolite /
- Cl- /
- F-
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Figure 3 SEM images of halogenated H-MOR catalysts
(a): H-MOR; (b): Cl-HMOR; (c): Cl-HMOR (U); (d): F-HMOR; (e): F-HMOR (U)
Figure 4 SEM images of fluorinated H-ZSM-5 catalysts
(a): H-ZSM-5; (b): F-HZSM-5; (c): F-HZSM-5 (U)
Figure 6 Effect of chlorination and ultrasonication on the pore size distribution in H-MOR catalysts
Figure 7 Effect of fluorination and ultrasonication on the pore size distribution in H-ZSM-5 catalysts
Figure 8 Effect of chlorination and ultrasonication on the pore size distribution in HY catalysts
Figure 10 Dimethyl ether (DME) in product of methanol conversion using H-MOR catalysts
Figure 11 Dimethyl ether (DME) and hydrocarbon selectivity at 300℃ using H-MOR catalysts
Figure 12 Dimethyl ether (DME) in product of methanol conversion using H-ZSM-5 catalysts
Figure 13 Dimethyl ether (DME) in product of methanol conversion using chlorinated and fluorinated H-Y catalysts
Table 1 Crystallite sizes of the phases present in XRD of zeolite catalysts
Catalyst Crystal size d/nm HMOR 42.8 Cl-HMOR 64.0 Cl-HMOR(U) 56.8 F-HMOR 43.9 F-HMOR (U) 42.4 H-ZSM-5 32.7 Cl-HZSM-5 38.3 Cl-HZSM-5(U) 31.3 F-HZSM-5 32.4 F-HZSM-5(U) 21.2 
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Table 2 Surface area and total pore volume values of different halogenated zeolites
Catalyst Total pore volume v/(cm3·g-1) Surface area A/(m2·g-1) H-MOR 0.22 350 Cl-HMOR 0.23 368 Cl-HMOR (U) 0.44 478 H-ZSM-5 0.32 357 F-HZSM-5 0.37 375 F-HZSM-5(U) 0.33 346 HY 0.38 435 Cl-HY 0.42 464 Cl-HY (U) 0.45 468
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Table 3 Ammonia TPD of the H-MOR catalysts
Catalyst Acid sites strength distribution ∆H /(J·g-1)a LT-peak temperature tmin/℃ HT-peak temperature tmax/℃b H-MOR 89.6 199 530 Cl-HMOR 84.3 204 533 Cl-HMOR (U) 80.5 210 537 a: proportional to acid sites number
b: proportional to acid sites strength
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[1] FLEISCH T H, BASU A, GRADASSI M J, MASIN J G. Dimethyl ether: A fuel for the 21st century[J]. Stud Surf Sci Catal, 1997, 107: 117-125. doi: 10.1016/S0167-2991(97)80323-0 [2] SEMELSBERGER T A, BORUP R L, GREENE H L. Dimethyl ether (DME) as an alternative fuel[J]. J Power Sources, 2006, 156(2): 497-511. doi: 10.1016/j.jpowsour.2005.05.082 [3] VISHWANATHAN V, JUN K W, KIM J W, ROH H S. Vapour phase dehydration of crude methanol to dimethyl ether over Na-modified H-ZSM-5 catalysts[J]. Appl Catal A: Gen, 2004, 276(1/2): 251-256. http://www.doc88.com/p-270338446980.html [4] CAI G Y, LIU Z M, SHI R M, HE C Q, YANG L X, SUN C L, CHANG Y J. Light alkenes from syngas via dimethyl ether[J]. Appl Catal A: Gen, 1995, 125(1): 29-38. doi: 10.1016/0926-860X(94)00291-6 [5] XU M T, GOODMAN D W and BHATTACHARYYA A. Catalytic dehydration of methanol to dimethyl ether (DME) over Pd/Cab-O-Sil catalysts[J]. Appl Catal A: Gen, 1997, 149(2): 303-309. doi: 10.1016/S0926-860X(96)00276-1 [6] KIM S D, BAEK S C, LEE Y J, JUN K W, KIM M J, YOO I S. Effect of γ-alumina content on catalytic performance of modified ZSM-5 for dehydration of crude methanol to dimethyl ether[J]. Appl Catal A: Gen, 2006, 309(1): 139-143. doi: 10.1016/j.apcata.2006.05.008 [7] VISHWANATHAN V, ROH H S, KIM J W, JUN K W. Surface properties and catalytic activity of TiO2 ZrO2 mixed oxides in dehydration of methanol to dimethyl ether[J]. Catal Lett, 2004, 96: 23-28. doi: 10.1023/B:CATL.0000029524.94392.9f [8] FEI J H, HOU Z Y, ZHU B, LOU H, ZHENG X M. Synthesis of dimethyl ether (DME) on modified HY zeolite and modified HY zeolite-supported Cu-Mn-Zn catalysts[J]. Appl Catal A: Gen, 2006, 304: 49-54. doi: 10.1016/j.apcata.2006.02.019 [9] YARIPOUR F, BAGHAEI F, SCHMIDT I, PERREGAARD J. Catalytic dehydration of methanol to dimethyl ether (DME) over solid-acid catalysts[J]. Catal Commun, 2005, 6(2): 147-152. doi: 10.1016/j.catcom.2004.11.012 [10] KIM S M, LEE Y J, BAE J W, POTDAR H S, JUN K W. Synthesis and characterization of a highly active alumina catalyst for methanol dehydration to dimethyl ether[J]. Appl Catal A: Gen, 2008, 348(1): 113-120. doi: 10.1016/j.apcata.2008.06.032 [11] TANG Q, XU H, ZHENG Y, WANG J, LI H, ZHANG J. Catalytic dehydration of methanol to dimethyl ether over micro-mesoporous ZSM-5/MCM-41 composite molecular sieves[J]. Appl Catal A: Gen, 2012, 413-414: 36-42. https://www.researchgate.net/publication/241102063_Catalytic_dehydration_of_methanol_to_dimethyl_ether_over_micromesoporous_ZSM-5MCM-41_composite_molecular_sieves [12] KESHAVARZ A R, REZAEI M, YARIPOUR F. Preparation of nanocrystalline γ-Al2O3 catalyst using different procedures for methanol dehydration to dimethylether[J]. J Natur Gas Chem, 2011, 20(30): 334-338. [13] RAOOF F, TAGHIZADEH M, ELIASSI A, YARIPOUR F. Effects of temperature and feed composition on catalytic dehydration of methanol to dimethyl ether over γ-alumina[J]. Fuel, 2008, 87(13): 2967-2971. https://www.researchgate.net/publication/223580243_Effects_of_temperature_and_feed_composition_on_catalytic_dehydration_of_methanol_to_dimethyl_ether_over_g-alumina [14] KHOM-IN J, PRASERTHDAM P, PANPRANOT J, MEKASUWANDUMRONG O. Dehydration of methanol to dimethyl ether over nanocrystalline Al2O3with mixed γ-and χ-crystalline phases[J]. Catal Commun, 2008, 9(10): 1955-1958. doi: 10.1016/j.catcom.2008.03.009 [15] MOLLAVALI M, YARIPOUR F, MOHAMMADI-JAM S, ATASHI H. Relationship between surface acidity and activity of solid-acid catalysts in vapour phase dehydration of methanol[J]. Fuel Process Technol, 2009, 90(9): 1093-1098. doi: 10.1016/j.fuproc.2009.04.018 [16] EBEID M F, ALI A, AMIN A, ABOUL-FOTOUH S. Heteropoly acids supported on α-Al2O3 as solid acid catalysts for methanol transformation[J]. Collect Czech Chem Commun, 1993, 58: 2079-2089. doi: 10.1135/cccc19932079 [17] AMIN A, ALI A, ABOUL-FOTOUH S, EBEID E F. Surface studies and nature of active sites of supported heteropolyacids as catalysts in methanol dehydration[J]. Collect Czech Chem Commun, 1994, 59: 820-832. doi: 10.1135/cccc19940820 [18] LIU D, YAO C, ZHANG J, FANG D, CHEN D. Catalytic dehydration of methanol to dimethyl ether over modified γ-Al2O3 catalyst[J]. Fuel, 2011, 90(5): 1738-1742. doi: 10.1016/j.fuel.2011.01.038 [19] JIANG S, HWANG J, JIN T, CAI T, CHO W, BAEK Y, PARK S. Dehydration of methanol to dimethyl ether over ZSM-5 zeolite[J]. Bull Korean Chem Soc, 2004, 25: 185-189. doi: 10.5012/bkcs.2004.25.2.185 [20] SUN KOU M R, MENDIOROZ S, SALERNO P, MUNOZ V. Catalytic activity of pillared clays in methanol conversion[J]. Appl Catal A: Gen, 2003, 240(1/2): 273-285. http://www.ingentaconnect.com/content/els/0926860x/2003/00000240/00000001/art00466 [21] LERTJIAMRATN K, PRASERTHDAM P, ARAI M, PANPRANOT J. Modification of acid properties and catalytic properties of AlPO4 by hydrothermal pretreatment for methanol dehydration to dimethyl ether[J]. Appl Catal A: Gen, 2010, 378(1): 119-123. [22] YARIPOUR F, BAGHAEI F, SCHMIDT I, PERREGAARD J. Synthesis of dimethyl ether from methanol over aluminium phosphate and silica-titania catalysts[J]. Catal Commun, 2005, 6(8): 542-549. https://www.researchgate.net/profile/Fereydoon_Yaripour/publication/244318987_Synthesis_of_dimethyl_ether_from_methanol_over_aluminium_phosphate_and_silica-titania_catalysts/links/53f0fa450cf2711e0c431db2.pdf?origin=publication_list [23] ABOUL-FOTOUH S M K, ABOUL-GHEIT N A K, HASSAN M M I. conversion of methanol using modified H-MOR zeolite catalysts[J]. Chin J Catal, 2011, 32(3): 412-417. http://www.cqvip.com/QK/93027X/201103/36993584.html [24] ABOUL-FOTOUH S M, ABOUL-GHEIT A K. Hydroconversion of cyclohexene using platinum-containing catalysts promoted with other noble metals and chlorine or fluorine[J]. Appl Catal A: Gen, 2001, 208(1/2): 55-61. https://www.researchgate.net/publication/229350948_Hydroconversion_of_cyclohexene_using_platinum-containing_catalysts_promoted_with_other_noble_metals_and_chlorine_or_fluorine [25] ABOUL-GHEIT A K, ABOUL-FOTOUH S M, ABDEL-HAMID S M, ABOUL-GHEIT N A K. Effect of hydrochlorination and hydrofluorination of H-ZSM-5 on the catalytic hydroconversion reactions of cyclohexene[J]. Appl Catal A: Gen, 2006, 297(1): 102-110. doi: 10.1016/j.apcata.2005.08.044 [26] LYCZKO N, ESPITALIER F, LOUISNARD O, SCHWARTZENTRUBER J. Effect of ultrasound on the induction time and the metastable zone widths of potassium sulphate[J]. Chem Eng J, 2002, 86(3): 233-241. http://www.academia.edu/27910093/Effect_of_ultrasound_on_the_induction_time_and_the_metastable_zone_widths_of_potassium_sulphate [27] TSAI T C. Application of zeolites in petroleum industries[J]. Catal Process, 1995, 3(4): 37-48. [28] ABOUL-FOTOUH S M. Cyclohexen reactivity using catalysts containing Pt, Re and PtRe supported on Na-and H-mordenite[J]. J Chin Chem Soc, 2003, 50(6): 1151-1158. doi: 10.1002/jccs.v50.6 [29] ASHIM K G, RONALD A K. Fluorine-promoted catalyst[J]. Catal Rev Sci Eng, 1985, 27(4): 539-589. doi: 10.1080/01614948508064233 [30] COVINI R, FATTORE V, GIORDANO N. Acidity of fluorinated aluminas, and their catalytic activity: Meaning and limits of a correlation[J]. J Catal, 1967, 9(4): 315-321. doi: 10.1016/0021-9517(67)90259-X [31] HIRSCHLER A E. The measurement of catalyst acidity using indicators forming stable surface carbonium ions[J]. J Catal, 1963, 2(5): 428-439. doi: 10.1016/0021-9517(63)90108-8 [32] WEBB A N. Hydrofluoric acid and acidity of alumina[J]. Ind Eng Chem, 1957, 49: 261-263. doi: 10.1021/ie50566a042 [33] ABOUL-FOTOUH S M, ABOUL-GHEIT A K. Hydroconversion of cyclohexene using platinum-containing catalysts promoted with other noble metals and chlorine or fluorine[J]. Appl Catal A: Gen, 2001, 208(1/2): 55-61. https://www.researchgate.net/publication/229350948_Hydroconversion_of_cyclohexene_using_platinum-containing_catalysts_promoted_with_other_noble_metals_and_chlorine_or_fluorine [34] ALI L I, ALI A A, ABOUL-FOTOUH S M, ABOUL-GHEIT A K. Hydroisomerization, hydrocracking and dehydrocyclization of n-pentane and n-hexane using mono-and bimetallic catalysts promoted with fluorine[J]. Appl Catal A: Gen, 2001, 215(1/2): 161-173. [35] ALI A G A, ALI L I, ABOUL-FOTOUH S M, ABOUL-GHEIT A K. Hydroconversion of n-paraffins in light naphtha using Pt/Al2O3 catalysts promoted with noble metals and/or chlorine[J]. Appl Catal A: Gen, 2001, 205(1/2): 129-146. [36] ABOUL-FOTOUH S M, ABOUL-GHEIT N A K, HASSAN M M I. Conversion of methanol using modified H-MOR zeolite catalysts[J]. Chin J Catal, 2011, 32(3): 412-417. http://www.cqvip.com/QK/93027X/201103/36993584.html [37] LE VAN MAO R, LE T S, FAIRBAIRN M, MUNTASAR A, XIAO S, DENES G. ZSM-5 zeolite with enhanced acidic properties[J]. Appl Catal A: Gen, 1999, 185(1): 41-52. doi: 10.1016/S0926-860X(99)00132-5 [38] ARENA F, FRUSTERL F, MONDELLER N, GIORDANO N. Interaction pathway of chloride ions with γ-Al2O3: Surface acidity and thermal stability of the Cl/γ-Al2O3 System[J]. J Chem Soc Faraday Trans, 1992, 88: 3353-3356. doi: 10.1039/FT9928803353 -
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