Solid superacid-catalyzed hydroconversion of an extraction residue from Lingwu bituminous coal

Intemational joumal of Mining Science and Technology 22(2012)251-254Contents lists available at SciVerse Science DirectInternational journal of Mining Science and technologyELSEVIERjournalhomepagewww.elsevier.com/locate/ijmstSolid superacid-catalyzed hydroconversion of an extraction residuefrom lingwu bituminous coalXiao-Ming Yue, Xian-Yong Wei", Bing Sun, Ying-Hua Wang, Zhi-Min Zong, Zi-Wu LiuKey Laboratory of Coal Processing and Efficient UtiHzation(Ministry of Education)and Low Carbon Energy institute, China University of Mining G Technology, Xuzhou 221008 ChinaARTICLE IN FOA BSTRACTA solid superacid was prepared as a catalyst. The catalyst was characterized by ammonia terReceived 31 August 2011Received in revised form 30 Septemberrogrammed desorption, surface property measurement, and analyses with scanning electpy and Fourier transform infrared spectrometry. a extraction residue from Lingwu subbitumirccepted 15 October 201was subject to non-catalytic and catalytic hydroconversion using cyclohexane as the solvent unAvailable online 7 April 2012surized hydrogen at 300C for 3 h. The results show that the total yieldether-extracarenes from catalytic hydroconversion is much higher than that fromhydroconeThe cleavage of Car-Calk bonds in the residue could significanthydroconversion.o 2012 Published by Elsevier B V. on behalf of China University of Mining TechnologyCoal liquefaction1 IntroductionCoal liquefaction is an important process for coal conversion 2 1 Materials and catalyst preparation11. 2). Many value-added chemicals can be obtained by coal lique-extensiveLSBC was collected from Lingwu Coal Mine in Ningxia Huiwork has been done coal liquefaction is not yet economically com- Autonomous Region of China. It was sequentially extracted withpetitive [3-6]. In addition, the mechanisms for coal liquefaction are methanol, petroleum ether(PE), benzene acetone and isometricot clear on the molecular level. Coal liquefaction residue usually acetone/carbon disulfide mixed solvent. The residue(RusBc)wasamounts to 30% of coal used [7 Efficient utilization of the residue dried in a vacuum at 80"C for 12 h.is important for improving the economics of coal liquefaction Cyclohexane and PE (b p 30-60 C)used in the experiments areprocess.commercially available reagents and were distilled prior to useCatalysts play important roles in coal liquefaction Metals such Activated carbon(AC), trimethylsilyl trifluoromethanesulphonateas Fe, Ni, and pd/c are well used catalysts for catalytic hydrogena- (TMSTFMS. and pentachloroantimony(PCa)were also commer-tion 8-13Shimizu et al. found that superacids such as HF/BF can promoteThe ac was ground to <75 um and dried in a vacuum at 80oCcoal depolymerization at 150C without significant dealkylation for 12 h. It was then impregnated with isometric TMSTFMS and14,15 USY-zeolite was found to exhibit a remarkable activity PCa under microwave irradiation for 20 min at 80C followedfor benzene, toluene and xylene production from coal hydrocrack- agitation for 12 h and filtration through a membrane. the filtering at temperatures near 600C[16 Many important processes of cake(FC)was dried in a vacuum at 80C for 12 h. the dried FCoal liquefaction, such as cracking hydrocracking, and reforming, was used as the ssa The SSa was characterized with a Nicoletare based on the cleavage of c-C bonds in coals [ 17, 18]Magna IR-560 Fourier Transform infrared( FTIR)spectrometry, anIn the present study. we prepared a solid superacid(SSA)and Autosorb-1-MP instrument, a Hitachi S-3700N scanning electroninvestigated the SSA-catalyzed hydroconversion of an extraction microscope(SEM) and a TP-5000 ll adsorption instrument.residue from Lingwu subbituminous coal(LSBC)2. General procedureding author Tel: +8651683885951中国煤化工 hexane(3om) were putCNMHGd autoclave. After b6/s-see front matter s 2012 Published by Elsevier B V on behalf of china Universitdoi. org/u01016/jms201203002Y Xiao-Ming et aL/ International Joumal of mining Science and Technology 22(2012)251-254Fig. 1. SEM micrographs of the catalyst.pressurized with hydrogen to 5 MPa at room temperature(20C)30015001000the autoclave was heated to 300C within 15 min and kept at thisemperature for 3 h. Then the autoclave was immediately cooledto room temperature in an ice-water bath. the reaction mixtureFig 2 FTIR spectrum of the catalyst.was taken out from the autoclave as completely as possible usingPE as the rinse solvent and filtered through a 0.8 um membrane fil- 3. Results and discussionter. The fC was extracted with pE in a Soxhlet extractor under a N2 3. 1. The SSa characterizationatmosphere for two weeks. The filtrate and extraction solution wereincorporated and concentrated by evaporating the solvents using arotary evaporator to afford concentrated PE-extractable fractiona desorption peak appeared at ca 600C in an ammonia tem-(PEEF), which was analyzed with a Hewlett-Packard 6890 /5973 perature-programmed desorption (NHy-TPD)profile, whichGC/MS using a series of authentic compounds as external standards. proved super acidity of the SSA prepared. The specific surface area,The yields of identified compounds were calculated based on dried specific pore volume, and average pore diameter of the SSA areand ash-free(dan) mass of rlsec488 m/g 0.38 m/g, and 3 12 nm, respectively、灯又Mx米八人A叫中国煤化工CNMHGFig3. Total ion chromatograms of the PEEFs from NCHC and CHC of rbC.Y. Xioo-Ming et ol/Intermational Journal of Mining Science and Technology 22(2012)251-254the gaps and macropores of the AC It could be concluded that theactive components are spread over the surface of AC. The loadcapacities of PCA and TMSTFMs were calculated by subtractionmethod to be 0.51 and 0.67 mol- g l of the Ac(dan, respectivelyThe absorbances of characteristic groups in TMSTFMSobserved in Fig. 2, including CF, SO,- at 1255 cm.(CH, )3Si-0-at 1178 cm", FaC-SO3-at 1034 cm ,-SOg-(symmetric)at643 cm",-CF3(symmetric)at 580 cm, and-SO, -(asymmetricat 519 cm-1. The absorbance of C-Cl at 799 cm can be also foundin the Ftir speindicating that the reaction of PCA with Acoccurred during the SSa preparation.Annas Phenols Es3. 2. GC/MS analysisFg 4 Distribution of group components in the PEEFs from NCHC and CHC of RusacIn total. 108 compou(CHC)of R\SBc as demonstrated in Fig 3. They can be classified intoTAble 1alkanes, arenes, phenols, esters, and other species(OSs). As Fig. 4Yiels of arenes detected in the PEEfs from NcHc and dHc of rLsecillustrates, the yields of group components in the PEEF from NCHCakCompoundYield (ug g". dan)of RusBc decrease in the order: alkanes> esters> phenols > OSsarenes, but the order changes to arenes > phenols >> OSs >esters>alkanes for the yields of group components in the PEEF from CHO(Er-but-1-enylbenzeneof RLsec. The total yield of the PEEF from CHC of Risc is much higher than that from NCHc of RIssc. Especially, dominantly moreamount of arenes yielded from CHC of Rlsec than from NCHc of923RLSHC. As Table 1 lists, in the PEEF from NCHC of RLsBc only seven36arenes were identified, but 44 arenes appeared in the peef fromCHC of Rusac. These facts clearly indicate that the SSA significantly2. 7-Dimethylnaphthalenecatalyzed the formation of GC/MS-detectable arenes from RLsBc33 &35 Dimethylnaphthalenes00000100000038sduring its hydroconversionThe yield of diphenylmethane(DPM, peak 32)is 1038. 9 uggand accounts for 34. 2% of arenes in the peef from Chc of rlsBcbut no DPM was detected in the PEEF of NCHC of R\sBc, indicating52&Bthat DPM should be a product from CHc of Ruse rather than a component originally existing in RLsBc Our recent work 19] showed6365that the SSa exhibited high activity for specifically cleaving the3. 3-BitolCar-Calk bond in di(l-nahthyl]methane(DNM)during catalyticPhenanthrenehydrocracking at 300 C and the transfer of H' generated overthe SSa with H2 to an ipso-position of DNM should be crucial stepfor DNM hydrocracking. Similar mechanism can be considered fothe formation of DPM from CHC of RLsBc. Diphenylmethyl group3.1(DPMG)could be present in RusBc and connected with a condensed7-lsopropyl-l-methylphenanthrene 2.0aromatic ring( CAR)such as anthracene ring(AR). As Schemedemonstrates, the addition of h to 9-position of AR leads to thecleavage of Car-Calk bond connecting DPMG with AR because ofhigh hydrogen-accepting ability of 9-position of AR and high stability of the leaving diphenylmethylium. Correspondingly. thecleavage of Car0 bond connecting phenoxy or alkylphenoxyAs Fig. 1 shows, the micro-sized support particles are asymmet- groups with a CAR should be responsible for dramatically higherrical and consist of irregular grains adhering to the rough surface of yields of phenols in the pEEF from CHC of rlsec than those fromthe AC. These particles adhere to the surface and also appeared in NCHC of Ru中国煤化工CNMHGScheme 1. A proposed pathway for the release of DPM during CHC of RusaY. xloo-Ming et aL/ Intemarional Journal o Mining Science and Technology 22(2012)251-2544. Conclusions4Kowrobkow VY, Kaiechitz IV Correlation betweenethanes assion. Predominantly higher amounts of arenes(especially DPM) (s) Murata s. Nakamura 9: 41(1:39-53.The Ssa proved to be an active catalyst for rusa hydroconverof coal modeland phenols were released from CHC of Rues than from NCHC of (6)Yoshio K, Fisar o aiha Fuel 1986: 5( 1585-90The SSA effective catalyzed the formation af H' from Hz and the [71 wei YB Zong ZM. Xie RL Peng YL Mou J Ma YM. et at. Solid superacidtransfer of the resulting H to CARs connecting arylmethyl, diphenn residueylmethy l, phenoxy or alkylphenoxy groups, leading to the signifi- 18) Weing YC, Wang XH, Reaction of di(1of arenes and phenols. The SSA-catalyzedrsion of coal extraction residues and coal liquefaction2a03t 3m652-z ower metals and metal-sulfur systems. Enerayder mild conditions not only facilitates the understand-molecular structures of the residues, but also providxerogel catalysts for the production of middapproach for obtaining value-added chemicals fromle residues110] Zhou SL Ni ZH. Yuan XH. Zong ZM. Wei xY Catalyses ofctive hydroge nat ion of 9. 10-diphenylanthracerAcknowledgments[11] Ni ZH, Zhang LF. Yuan XH, Zong ZM, Wei XY. Relationship between structuresIs work was subsidIzed by the special Fund for12x2m加所如xn)mtional Natural Science Foundation of China for innovative ResearchGroup(No. 50921002. the Key project of Natural Science Founda[13] Wang M]. Yang HM, He XF, Chang UP. Effect of Fe-based minerals on pyrolysisacteristic of coal from westem China. J China Univ Min Technoltion of China(No. 20936007), the Key Project of Coal Joint Fund10393)426from National Natural Science Foundation of China and Shenhua [14] Shimizu k,Karamatsu H,Iwami YInabaGroup Corporation Limited(No. 51134021) National Natural Sci-ild conditions. Fuel Process Technol 1995: 45(2): 85-94.ence Foundation of China(No, 51074153)], the Program of the Uni- [15] Shimizu k,Kawindustries(No. JHB05-33), and the Priority Academic Program u6 Chareonpanich M, hang zc. Nishijima a tomita A6):t22Development of Jiangsu Higher Education Institutions.117 Kah k Nuel 1995:74(11): 1630-40 arbors in hydrocracking of coal volatileReferenceseactions of coal molecules and coal model compounds. Fuel Process TechnolIl Artok L. Erbatur O, Schabert HH. Reaction of dinaphthyl and diphenyl ethers at [18] Pellegrini LA. Gamba Calemma V, Bonomi s Modelling of hydrocracking[2 We XY. Ogata E, Zong ZM Zheu SL Qin ZH. Liu jz et al. Advances in the study 119) Yue XM, Wei XY, Sun B, Wang YH, Zong ZM. Far.X e: al. A new solid acid formodel compoundsIfically cleaving the Ca-C,a bond in d(l-naphthyl)methane. Appl Catal A[3]Zong ZM. Wei XY. Effects of molecular hydrogen and hydrogen donor additiveson 1, 2-di( 1-naphthyl)ethane thermolysis. Fuel Process te中国煤化工CNMHG