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Synthesisof Cumene (Isopropyl Benzene) from Rosin Oil Through Cracking And Dehydrogenation Savitri1, Mohammad Nasikin2, Nino Rinaldi1, Dadi Ramdani1 1 Indonesian Institute of Sciences, Research Centre for Chemistry Departement of Chemical Engineering, Faculty of Engineering, Indonesian University 2 Abstract Cumene has been synthesized from rosin oil through cracking and dehydrogenation reactions using modified HZSM-5 catalyst. The research has successfully modified the zeolite-based solid acid catalyst by adding Cu-Ni and Ni-Mo metal as promoter. Modified HZSM-5 catalysts were characterized using gravimetry and FTIR-pyridine method, the result shown that the acidity of the catalyst was decreased. Catalyst activity test for cracking and dehydrogenation reactions were carried out to obtain condition of cumene prodution. The final products were analyzed using FTIR and GC-MS. Cu-Ni/HZSM-5catalyst was suitable for the cracking-dehydrogenation reactions of rosin oil to produce cumene with process conditions of 30 bar and 450oC Keywords: cumene;rosin oil; cracking; dehydrogenation, modified HZSM-5, acidity. Abstrak Telah dibuat senyawa cumene dari minyak gondorukem (rosin oil) melalui reaksi “Cracking” dan dehidrogenasi menggunakan katalis HZSM-5 termodifikasi. Penelitian ini berhasil melakukan modifikasi terhadap katalis asam padat berbasis zeolit dengan menambahkan promotor logam Cu-Ni dan Ni-Mo. Katalis HZSM-5 termodifikasi dikarakterisasi menggunakan metoda gravimetri dan FTIR-pyridine yang menunjukkan terjadi penurunan keasaman katalis.Uji aktivitas katalis untuk reaksi “Cracking”dan dehidrogenasi dilakukan untuk mendapatkan kondisi proses yang mengarah kepada produk senyawa cumene. Analisa produk akhir menggunakan GC-MS. Katalis Cu-Ni/HZSM-5 mampu melakukan reaksi “Cracking”-dehidrogenasi gondorukem sehingga menghasilkan cumene . Proses tersebut terjadi pada kondisi 30 bar dan 450o C. Kata Kunci : cumene, minyak gondorukem, perengkahan, dehidrogenasi, HZSM-5 termodifikasi, keasaman. 1 INTRODUCTION Cumeneorisopropylbenzeneis usuallysynthesizedfromalkylationof benzenewithisopropylalcoholderivedfrom petroleum.Butpetroleum is un-renewable resourcewhich isdwindlingreserves every year.Cumene can be used as additive for raising the octane number of gasoline.[1] The consumptionof petroleumincrease every year due to lower productionof nationalpetroleumexplorationactivities,which isencouragethe search foralternativesourcesof raw materialsthatcanbe processedintocumene. resourceisvegetableoil.Vegetableoilisgenerallycomposed The oftriglyceridesandfree fattyacidscontaininghydrocarbon compounds whichis almost similar with chemical structure of petroleum. Severalstudies have beenconductedtoconvertvegetable oils intomore valuableproducts,for example the convertion of vegetable oilinto methyl ester. The vegetable oilwasobtainedfrompalm,coconut,soybean, jathropaandothers. Butthe vegetable oilisussually usedmostly asedible oil, so it bring the controvertion with theissue of foodsouverignity. Thereforetheproducts ofthe forestindustry residuessuch aspine resin, gumrosin, ortalloil (byproductof paperindustry) were studied forthe possibilitytobe convertedinto fuelorotherchemicalproducts.[2] Rosin oil is made up of a number of differentditerpenoid (resin) acids, diterpene alcohols, aldehydesand hydrocarbons.All the resin acids have the same basicstructure and would result in the same product oncomplete hydrogenation with no cleavage of bonds. Mostly rosin oil is exported as raw material according to this research.[3] Therosinoil used as a raw material for this workcontains resin acid, turpentine and other chemical compound.Table 1 shown neoabietic acid, dehydroabietic acid and abietic acid are the main composition (35,55 %, 17,15 % and 17,08 %) in rosin oil. Meanwhile Figure 1 shows the chemical structure of major component in rosin oil. Table 1.Major component of Rosin Oil [GC-MS analysist] Compound α-pinene (turpentine) camphene Delta-3-carene limonene borneol Neoabietic acid 2 (%) 5,47 4,42 5,10 8,73 6,50 35,55 Dehydroabietic acid Abietic acid H H O HO 17,15 17,08 O O abietic acid HO HO dehydroabietic acid neoabietic acid Figure1.Chemical structures of major components in rosin oil. The previous research on rosin oil shown that, the distillate of rosin oil was succesfully converted into methyl ester, and the product was suitable as fuel for bio-diesel and gasoline.[4] Another studyon fuel generation was using rosin oil as alternative source by cracking catalytic processes.The catalysts were HZSM-5 and Ni-Mo or Co-Mo commercial.[2] On the other hand, a researchonthe hydrogenation/dehydrogenationprocess ofrosinoilusingNi/Y-zeolite catalysthas beendone.The resultwas p-cymene as intermediate product (p-cymene has similarity chemical structures with cumene) and toluene was the final product.[5]Latelyresearch on bio-diesel production[6], was made by the transformation of tall oil into a bio-diesel in hydrotreating process using Ni-Mo/Al2O3 and Ni-W/Al2O3-zeolite catalyst.Another study on the convertion of tall oil[7]were pyrolysis of tall oil rosin and tall oil fatty acid. The end productswere aromatic hydrocarbon compounds namely benzene, toluene, cumene, indan, naphthalene, phenanthrene and phenol. The idea for this work is based on the previous researches. The question is, Is the major component in rosin oil can be converted into another chemical compound such as cumene (isopropyl benzene). Using HZSM-5 as the heterogeneous solid acid, will be modified with metal promoterssuch as cuprum-nickel and nickel-molybdenum to reduce the acidity or the acid strength. The solid catalyst with suitable acidity could crack and dehydrogenate rosin oil into cumene as the final product. The modified catalysts would be analyzed forits acidity using gravimetry and FTIR-pyridine method. Thefinalproducts will be determinedusingGCMS. MATERIALS AND METHODS 3 Preparation of Catalysts Thecatalystsusedforthe experimentswere comercial zeolite (HZSM-5) which is modified using metal promoterNickel (Ni), cuprum (Cu) and molybdenum (Mo). CuNi/HZSM-5 and Ni-Mo/HZSM-5 were a dual functioncatalystswhich are common in a cracking and hydrogenation/dehydrogenationreactionunitofrefinedcrudeoil. HZSM-5 isanacid mineral that can promote cracking reaction, while Cu, Ni and Mo are neededtopromotedehydrogenationafterthe cracking.[8] The comercial zeolite (HZSM-5) CBV 2020E typewith mole ratio of SiO2/Al2O3 = 30, Na2O weight 0,1% and surfaceareaof 400 m2/gram. HZSM-5 wereanalyzedwith XRF and thecompositionwere: 0,24% ZnO; 0,22% TiO2; MgO< 0,001%; 0,23% BaO; Na2O < 0,001%; 0,49% Fe2O3; 0,005% CaO; 0,073% K2O; 89,65% SiO2 and4,66% Al2O3. Cuprum and nickelwereimpregnatedtothe HZSM-5 byaddingCu (NO3)2.3H2O andNi(NO3)2.6H2Oaqueoussolution.To obtain Cu-Ni/HZSM-5 catalyst, nickel loading was 5% and cuprumloadingwas 5%weightas same as the nickel loading. After each impregnation, the catalyst was dried at 100°C over night and later than calcified at 500°C for 5 hours. Nickel and molybdenum were impregnated to HZSM-5 by addingNi(NO3)2.6H2O and(NH4) Mo7.O24.4H2Oaquaeoussolution. To obtain Ni-Mo/HZSM-5, molybdenum loading was 15% weight of MoO3and nickel loading was 5% weight of NiO. Later than, the catalyst had the same treatment as the preparation of Cu-Ni/HZSM-5 catalyst.The modified HZSM-5catalysts were determined using gravimetry and FTIR-pyridine method to observe the acidity and Brönsted-Lewis acid sites. Cracking and Dehydrogenation Cracking and dehydrogenationreactions of rosinoilwerecarriedout in an autoclave batchreactorwithpressure of 30 – 60 bar and temperature of 400 – 450º C.In the experiment, Rosinoilwasweighed 50 gramandcatalystwas 1 % (w/w) fromrosinoil. Thetwocomponentswereput in the reactor and thetemperaturewasadjusted at 400º C. Theduration of cracking and dehydrogenation processes was 1 hourafterthereactiontemperature achieved. The final productwascharacterized usingFTIR andGC-MS. The analysis of chemical compound and the chemical structure of rosin oil and the product usingAgilent Technologies 6890 Gas Chromatograph 5973 Mass Selective Detectorwith data process of Chemstation which is equipped with coloumnkapiler HP Ultra 2 (17 m x 0.25 mm id. and film thickness was 0.25 μm). 4 RESULT AND DISCUSSION Acidity properties of modified HZSM-5 The acidity properties of HZSM-5 and the modified HZSM-5 were analyzed using gravimetry-pyridine adsorption method.The method was counting the adsorption of pyridine in the surface of catalyst. The amount of pyridine which adsorbed was observed by gravimetry method. The results were the acid amount with assumption that the size of pyridine molecule was large enough which can be adsorbed at the surface of catalysts.[9]Acid amount of the catalysts were shown at table 2. Table2. Acid amount of modified HZSM-5 Catalyst HZSM-5 Acid amount (mmol/gram) 0,41 Ni/HZSM-5 0,24 Ni-Mo/HZSM-5 0,23 Cu-Ni/HZSM-5 0,23 As we can see in the Table 2. The HZSM-5 had the highest acid amount.The incorporation of nickel (Ni/HZSM-5) decreased the acid amount of HZSM-5. The adding of another metal promoter (Cu-Ni/HZSM-5 and Ni-Mo/HZSM-5) has reduce the amount of the acid of modified HZSM-5 lower. The reduction of acid amount after promoter metals impregnation due to the promotersimpregnation. The promotor metals were impregnated at the surface of HZSM-5 successfully. The first idea was to modified HZSM-5 catalyst to minimize the acidity.Therefore, the modified catalysts could carry out the cracking and dehydrogenation of rosin oil to produce cumene. The previous researches [5,10] produced several hydrocarbon components such as phenanthrene, naphthalene, cumene, toluene, benzene, and pentene using the same method. The lower acidity of modified catalysts could stop cracking and dehydrogenation of rosin oil and resulting cumene as the final product respectively. The FTIR analysis of catalysts (Brönsted and Lewis acid site) To observe Brönsted and Lewis acid sitesof modified HZSM-5 qualitatively were using FTIR. The acid sites were observed at wave numbers of 4000 – 400 cm-1. The Lewis acid site was shown at 1450 cm-1.[11]The pyridine ions were attached with Lewis acid on catalysts. The infrared spectra of modified catalysts were recorded for the analysisof Brönsted and Lewis acid sites with wave numbersbetween 1700- 1400 cm-1. The assignment of 5 frequencies for pyridine adsorbed on Brönsted and Lewis acid sites aresummarized[12]inTable 3. Table3. Assignment of frequencies for pyridine adsorbed on Brönsted and Lewis acid sites.[12] Wave number (cm-1) Assignment 1440 Hydrogen-bonded pyridine. 1450 Pyridine molecules adsorbed on Lewis acid sites. 1490 Hydrogen-bonded pyridine and pyridine molecules adsorbed on Brönsted and Lewis acid sites. 1545, 1620 – 1650 Pyridine molecules adsorbed on Brönsted acid sites. 1620 - 1630 Pyridine molecules adsorbed on Lewis acid sites. The FTIR spectrum of pyridine adsorption on HZSM-5 and modified HZSM-5 are shown in figure 2. As we can see from figure 2 (1), HZSM-5catalysthas both the acid sites (Brönsted and Lewis acid sites), one Lewis acid site is shown at wave number 1450 cm-1, and the Brönsted acid sites are shown at wave number 1545 and 1640 cm-1. This catalyst also has hydrogen-bonded pyridine and pyridine molecules adsorbed on Brönsted and Lewis acid sites[12]at 1490 cm-1. But after HZSM-5 was impregnated with nickel metal, the acid sites of catalyst (Ni/HZSM-5)was changed. Ni/HZSM-5 catalyst, figure 2 (2) only has two Lewis acid sites at 1460 cm-1 (the wave number is shifted from 1450 to 1460 cm-1) and 1620 cm-1, the Brönsted acid sites are not seen at all. Brönsted Lewis Brönsted dan Lewis (4) (1) HZSM-5 catalyst (2) Ni/HZSM-5 %T (3) (4) Ni-Mo/HZSM-5 (2) (1) 1700 (3) Cu-Ni/HZSM-5 1600 1500 1400 Wave number (cm-1) Figure 2.FTIR spectra of catalysts 6 1300 Then after Ni/HZSM-5 was impregnated with cuprum metal, the acid sites of catalyst (Cu-Ni/HZSM-5) was changed again. The Brönsted and Lewis acid sites appeared again at wave number 1490 cm-1, although the spectrum peak was not too sharp if it compared with the spectrum peak of HZSM-5. Cu-Ni/HZSM-5 catalyst,figure 2(3) has two Lewis acid sites at wave number 1630 cm-1 and 1450 cm-1. Meanwhile Brönsted acid sites is shown at wave number 1640 cm-1 although the spectrum peak is almost broad and not sharp enough as well as the HZSM-5. When the metal promoters which were impregnated into HZSM-5 were nickel and molybdate (Ni-Mo/HZSM-5), the acid sites was changed again. It only has one Lewis acid site at wave number 1450 cm-1 and one Brönsted acid site at 1630 cm-1. But the spectrum peak of Cu-Ni/HZSM-5 at wave number 1450 cm-1 is the sharpest among the HZSM-5 (1), Ni/HZSM-5 (2) and Ni-Mo/HZSM-5 (4). It is assumed that the type of metal promoters influence acidity of HZSM-5 catalyst. It has something to do with the framework, pore size and morphology of the HZSM-5 and the modified HZSM-5.[12]The most important thing is the impregnation of metals can reduce acidity or acid strength of HZSM-5 and resulting suitable acid catalyst.Therefore rosin oil can be converted into cumene by cracking and dehydrogenation reaction. After the modified catalysts were tested for the activities then we can see the connection impregnation process to produce solid acid catalyst with cracking and dehydrogenation reaction of rosin oil. The GC-MS analysis of rosin oil and products The rosin oil and product were analysized using GC-MS. The chromatogram GC-MS of rosin oil and product are shown in figure 3 and 4. A b u n d a n c e T IC : S 2 _ U L .D 7 3 . 17 46 . 1 0 7 7 .4 0 9 0 0 0 0 0 8 0 0 0 0 0 7 8 .7 4 7 0 0 0 0 0 6 0 0 0 0 0 7 8 .3 8 7 5 .5 3 2 0 .4 9 5 0 0 0 0 0 4 0 0 0 0 0 7 8 .5 5 2 4 .4 7 77 55 .. 01 49 7 8 .2 4 2 1 .3 2 7 5 .9 0 2 5 .4 1 3 3 .7 7 3 0 0 0 0 0 7 3 .8 8 3 2 .6 6 6 6 .1 6 2 0 0 0 0 0 7 2 .0 7 2 5 . 1 29 8 . 5 3 1 0 0 0 0 0 1 5 .0 0 2 0 .0 0 2 5 .0 0 3 0 .0 0 3 5 .0 0 4 0 .0 0 4 5 .0 0 5 0 .0 0 5 5 .0 0 6 0 .0 0 6 5 .0 0 7 0 .0 0 7 5 .0 0 8 0 .0 0 T im e - - > Figure3.GC-MS of rosinoilbeforereaction. 7 In figure 3, the main components in raw material are shown at retention time between 20,49 – 33,7 minute and 66,16 – 78,74 minute. The major component of rosin oil are shown at table 1. At figure 4, rosinoilwascracked and dehydrogenatedusing HZSM-5 catalyst(weighed 1% of raw material)withpressure of 60 bar and temperatura of 400º C. There are severalnew component are shown at retention time of 24,40 – 53,51 minute. Abundance T IC : S 7 .D 5 0 .7 8 7000000 5 3 .5 1 6000000 5000000 4 7 .9 7 2 9 .3 2 4000000 4 54.66 .37 43 9 . 4 0 4 3 . 9 3 4 74. 87 .38 6 4 8 .9 4 3000000 1 7 .5 8 2000000 1 1 .8 1 1000000 1 0 .0 0 4 6 . 8 745 90 5..911511.24.94 4 4 1 . 3 4 4 44.58 .59 4444999..1.36913 4 2 . 8 24 64. 17 8. 5 2 3 7 .1 9 5 4 .2 4 3 4 . 33036 7. 7. 40 3 4 14. 62 49. 94 3. 34 346 47.4457.8251..80163 5 05.52892.750. 65 9 4422. 2. 689 3 23 .37 .27 5 2 7 .8 1 2 0 .7 6 1 5 .2 5 1 51. 63 .15 1 1 7 . 6 8 2 2 .2643. 4 0 1 5 .0 0 2 0 .0 0 2 5 .0 0 3 0 .0 0 3 5 .0 0 4 0 .0 0 4 5 .0 0 5 0 .0 0 5 5 .0 0 6 0 .0 0 T im e --> Figure 3.GC-MS of productafterreactionusing HZSM-5catalyst Fromthechromatograms of theseprocess, almostall rosinoilwasconvertedintoanothercompounds. neoabieticacidanddehydroabieticacid)are camphene, delta-3-carene, of component of Theresinacids(abieticacid, notfound in limonene productsanylonger. Turpentine, andborneolarenotseeneither. Cumenewasformedalthoughonly in relatively small concentration. Themajorcomponent of end productisphenanthrene. Therosinoilwascracked and dehydrogenatedusingNi/HZSM-5, Cu-Ni/HZSM-5 and Ni-Mo/HZSM-5catalystswiththesamecondition of thefirstprocess.Thewholecomponents of products are shown at table4. Table 4.GC-MS of products from cracking – dehydrogenation reactions No. Compound HZSM-5 Ni/HZSM-5 Cu-Ni/HZSM-5 Ni-Mo/HZSM-5 1. 2. 3. 4. Pentane Toluene p-xylene Cumene % 5,47 0,89 0,27 0,59 1,33 0,23 8 1,44 0,49 1,69 0,19 5 6. 7 8. 9. P-cymene 1-methyl-indan Naphthalene Phenantrene Dehydroabietic acid 7,71 5,30 80,64 - 6,93 39,07 51,12 0,47 1,89 17,62 79,05 - 4,50 2,06 8,99 78,20 2,84 From Table4is seen that, HZSM-5 and themodified (Ni/HZSM-5, Cu-Ni/HZSM-5, NiMo/HZSM-5) could crack and brokethe–COOHgroup at abieticacid,neoabietic acid anddehydroabietic acid and reduce the hydrogen bonds (dehydrogenationreaction) of theresinacidstoformaromaticcompound.Buttheselectivity thosecatalystsweredirectedintonaphthalene and of phenanthrenecomponents,althoughCu- Ni/HZSM-5 catalysthadthehighestselectivityto produce cumene (1,44%) at the pressure of 60 bar and temperature of 400º C. In ordertoobtainhighercompotition of cumene, thereactionswerecarriedoutagainbyvariatingthepressureprocess(30, 45 and 60 bar). Thecomponentsof productswithvariation of pressureare shown at table5 and figure 5. Table5.GC-MS of products from cracking – dehydrogenation(T = 450º C.) No. 1 2 3 4 Compound Cumene 1-methyl-indan Naphthalene Phenantrene % 60 bar 1,44 1,89 17,62 79,62 45 30 bar bar 2,64 3,27 3,16 1,72 38,34 37,01 57,04 58,01 Table 5 showed the process of cracking by 30 bar of pressure better than the other. The lower pressure is needed in this process because the reaction was exotherms, other words, cracking-dehydrogenation need high temperature and low pressure. 9 Figure 5. Yield of cumene at 450º C in various pressure CONCLUSION The cracking-dehydrogenation using modified HZSM-5 could be used in the convertion of rosin oil into cumene.The Cu-Ni/HZSM-5 catalyst had the highest selectivity to produce cumene.The best operation condition of cracking-dehydrogenationprocess of cumene was at30 bar and temperatur 450o C.The cumene concentration was 3,27%. Future activity on the optimation of the processes to have better yield of cumene is necessary. REFERENCES [1] Ginting,E.D., 2012, SkripsiPra-rancanganPabrikCumenedariPropylendan Benzene, Universitas Sumatera Utara. [2] Coll, R., Udas, S., Jacoby, W.A., 2001, Conversion of the Rosin Acid Fraction of Crude Tall Oil into Fuels and Chemicals, Energy & Fuels, 15:1166-1172. [3] Silitonga, T, dan S. Suwardi, 1977, Penurunan Kualitas Gondorukem Selama Penyaringan di Jawa Timur. Laporan: 87:2-10. [4] Mulyaningrum, 2008, Metil Ester Gondorukem Sebagai Kandidat Bahan Bakar Nabati, Tesis, Sekolah Pasca Sarjana, Institut Pertanian Bogor. [5] Dutta, R.P.,Schobert, H.H., 1993, Hydrogenation/Dehydrogenation Reactions Of Rosin, Symposium Fall (CHICAGO) 38(3) Biomass, MSW/Wastes or By-Products Utilization/Characterization. [6] Mikulec, J., Kleinova, A., Cvengros, J., L’udmila, J., Banic, M., 2011, Catalytic Transformation of Tall Oil into Biocomponent of Diesel Fuel, International Journal of Chemical Engineering, Volume 2012, ID 215258, Hindawi Publishing Corporation. [7] Lappi, H., Alen, R., 2012, Pyrolisis of Tall Oil-Derived Fatty and Resin Acid Mixtures, ISRN Renewable Energy, Vol. 2012, ID 409157. 10 [8] Nasikin, M., Susanto, B.H., Hirsaman, M.A., Wijanarko, A., 2009, Biogasoline from Palm Oil by Simultaneous Cracking and Hydrogenation Reaction over Ni/Mo/Zeolite Catalyst, World Applied Sciences Journal 5: 74-79. [9] Rodiansono, Trisunaryanti, W., Triyono, 2007, Preparation, Characterization and Activity Test of NiMo/Z and NiMo/Z-Nb2O5, Berkala MIPA 17 (2). [10] Sharma, R.K., Bakhshi, N.N., 1991, Catalytic conversion of crude tall oil to fuels and chemicals over HZSM-5: Effect of co-feeding steam, Fuel Processing Technology, 27, 113-130, Elsevier Science Publisher B.V., Amsterdam. [11] Selli, E., Forni, L., 1999, Comparison Between the Surface Acidity of Solid Catalyst Determined By TPD and FTIR Analysis of Pre-Adsorbed Pyridine, Journal of Surface Chemistry, Vol. 31. [12] Amin, N.A.S., Anggoro, D.D.,2003, Characterization and Activity of Cr, Cu and Ga Modified ZSM-5 for Direct Conversion of Methane to Liquid Hydrocarbon, Journal of Natural Gas Chemistry 12 (2003) 123 – 134, Science Press. 11