IJOER-MAY-2016-1

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Published on May 30, 2016

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slide 1: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 34 Bio-Oil Production from Pyrolysis of Coffee and Eucalyptus Sawdust in the Presence of 5 Hydrogen Zeban Shah 1 Renato Cataluña Veses 2 Rafaela A. Aguilhera 3 Rosangela da silva 4 123 Federal University of Rio Grande do Sul Av. Bento Gonçalves 9500 91501-970 Porto Alegre RS Brazil 4 PontificalCatholic University of Rio Grande do Sul Av Ipiranga 6681 90619-900 Porto Alegre RS. Brazil Abstract— In this paper we have done some important analysis of bio-oil obtained from the pyrolysis of coffee and eucalyptus sawdust in the presence of 5 Hydrogen. The bio-oil was obtained in one step pyrolysis in which temperature of the system was kept 25ºC and then increased up to 850ºC. After pyrolysis the obtained dark sticky liquid highly viscous bio- oil was introduced to thermal cracking. During thermal cracking the bio-oil was condensed at two different temperatures 100ºC and 5ºC so we got two types of bio-oil BHTT bio-oil obtained at high temperature 100 ºC after thermal cracking and BLTT bio-oil obtained at low temperature 5ºC after thermal cracking. Then both types of bio-oil were distillated and analyzed in Gas chromatography and Mass spectrometry GC-MS technique and comprehensive two-dimensional gas chromatography with time-of-flight mass spectrometry detection GC×GC/TOFMS. Agriculture residue bio-oil and its thermal cracking fractions could be effectively characterized by GC/MS and GC×GC/TOFMS where the light fraction was composed of a wide range of lower polarity compounds while heavy fraction had higher polarity compounds. Keywords— Chromatographic analysis GC/MS GC×GC/TOFMS biomass pyrolysis bio-oil production. Abbreviations: BESC: Bio-oil produced from Coffee and Eucalyptus Sawdust BHTT: Bio-oil condensed at100ºC High Temperature after Thermal cracking BLTT: Bio-oil condensed at 5ºC Low Temperature after Thermal cracking I. INTRODUCTION The Bio-oil resulting from the pyrolysis process consists of a mixture of more than 300 organic compounds .In terms of environmental issue biodiesel is more adoptable compare to fossil fuel as it forms low carbon and smoke which are responsible for global warming.Among several biomass energy conversion methods microwave assisted pyrolysis offers low temperature and energy efficient route to convert solid waste biomass resources to energy products. In United States soybean is used for the production of biodiesel. “Bio-fuels done right” must be derived from feed stocks with low greenhouse gas emissions and little or no competition with food production 1-5 .On the other hand biodiesel has higher molecular weight density viscosity and pour point than conventional diesel fuel 67. Higher molecular weight and viscosity of biodiesel causes low volatility and poor fuel atomization injector coking piston ring sticking and leading incomplete combustion 8. as well as it has cold flow property which is a barrier to use it in cold or chill weather 9. Anyhow the best benefit of Bio- oils is that they are preparing from renewable sources like corpse plants trees and residues etc. Approximately 100 years ago Rudolf Diesel tested Bio oil as the fuel for his engine that was available with him 10 11. According to scientists and researchers there are 350 oil containing crops and plants identified among them only soybean rapeseed coffee sunflower cottonseed peanut and coconut oils are considered that they have the potential and quality of alternative fuels for Diesel engines 12 13. Bio oils have the capacity to substitute for a part or fraction of the petroleum Products distillates and petroleum based petrochemicals in the future. Due to being more expensive than petroleum Bio-fuels are nowadays not petroleum competitive fuels However due to the misuse high expenditure and increases in petroleum prices and the uncertainties concerning petroleum availability there is renewed interest in using Bio-oils in Diesel engines 14. The emergence of transesterification can be dated back as early as 1846 when Rochieder described glycerol preparation through methanolysis of castor oil and since that time alcoholysis has been studied in many parts of the world. Scientists researchers have also investigated the important reaction conditions and parameters on the alcoholysis of triglycerides such as tallow fish oils sunflower soybean rapeseed linseed oils cottonseed sunflower sa fflower and peanut 1516. Soybean oil was transesterified into ethyl and methylesters and comparisons of the performances of the fuels with diesel were made.1718.Also methylesters have been prepared from palm oil by transesterification using methanol in the presence of a catalyst NaOH or KOH in a batch reactor. Ethan oils a preferred alcohol in the transesterification process compared to methanol because it is derived from natural agricultural products and is renewable and biologically less objectionable in the slide 2: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 35 environment. The success of rapeseed ethylester production would mean that biodiesel`s two main raw materials would be agriculturally produced renewable and environmentally friend 19 20. Methyl ethyl 2-propyl and butyl esters were prepared from canola and linseed oils through transesterification using KOH and/or sodium alkoxides as catalysts. In addition methyl and ethylesters were prepared from rapeseed and sunflower oils using the same catalysts 21- 24. In the last few decades the significant global warming problems caused by CO2 have been magnified by the continued and increasing use of petroleum in diesel engines. Reducing CO2 emission has become an explicit goal of policy measures to support the use of biofuels. For example European Union mandates 10 share for biofuels in the EU European Union total energy mix by 2020 25 and United States sets a total of 36 billion-gallon target for biofuels production by 2022 26. Therefore alternative renewable biofuels have been investigated to partly or completely replace diesel fuel to overcome the emission problems 27-30. II. EXPERIMENTAL 2.1 Materials: coffee eucalyptus sawdust and other reagents The bio-oil was obtained by pyrolysis of a mixture 1:1 in mass of coffee grounds and eucalyptus sawdust. Coffee grounds and eucalyptus sawdust were mixed after their granulometric reduction till 0.21 mm. Calcium oxide CaO was added to this mixture at 20 in mass and sufficient amount of water to produce a malleable mixture that could be fixed and conformed in cylinders. After building the cylinders they were dried at environmental temperature during 3 days. Before the pyrolysis the system was purged during 20 minutes with Argon and with 5 of hydrogen 100 mL/min. 2.2 Production of BESC The bio-oil was produced from the pyrolysis of coffee grounds and eucalyptus sawdust in the presence of 5 hydrogen. A round block shaped structure of sample was made inside the filter paper from filter paper as side wall of the sample block to keep the biomass tight biomass while the weight of this sample was kept 300grams after preparation of this sample block it was kept inside a stainless steel reactor of pyrolysis system which is further connected to two other chambers which are shown in diagram in figure 1.The temperature of reactor was increased from 25ºC - 850ºC with help of heater temperature controller cabinet and two condensation chambers through which biomass was converted to biogas and then the biogas was condensed in other two chambers which condensed fractions of biogas to bio-oil on temperature 100ºC and 5ºC after pyrolysis and thermal cracking . The two condensed fractions from these chambers BHTT BLTT were collected and introduced to further analysis. BIOMASS Pyrolysis system 7c COOLER Heater Hot water/ Small heater 100c 7c 100c 800c High Fraction Low Fraction BIOMASS HOT BIOGAS Condensed BIOGAS with TEMP 7C/L and 100C/H PUMP 5 H2 and Argon Condensing biogas at 7c and 100c FIG.1. BIOMASS PYROLYSIS SYSTEM. slide 3: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 36 2.3 GC-MS Analysis of BHTT BLTT The bio-oil identification and composition determination were performed on a GC Agilent series 6890 with a Agilent mass selective detector of series 5973A capillary polar wax column polyethylene glycol PEG-coated length of 30 m internal diameter of 0.25 mm and film thickness of 0.25 μm Chromatographic conditions were as follows: Injection volume of 0.2 μL oven at 40°C 1 min 6°C min−1 up to 300°C 10/Min split mode with a ratio of 100:1 and injection temperature of 290 °C. Time taken was 54.3 minutes He helium as carrier gas with a flow rate of 2.9 mL min−1 III. GC-MS CHROMATOGRAMS OF BESC Below fig 2. And fig 3. Are different chromatograms of BHTT and BLTT respectively which show different peaks for different compounds in both cases. FIG.2. DONE WITH SPLITLESS MODE WHERE DIFFERENT PEAKS SHOW DIFFERENT COMPOUNDS IN BHTT AT DIFFERENT RETENTION TIME FIG.3. DONE WITH SPLIT MODE WHERE DIFFERENT PEAKS SHOW DIFFERENT COMPOUNDS IN BLTT AT DIFFERENT RETENTION TIME slide 4: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 37 TABLE 1 ALIPHATIC AROMATIC HYDROCARBONS DETECTED IN BLTT WITH THEIR RETENTION TIME NO NAME OF COMPOUND FORMULA RETENTİON TİME 1 3-Undecene Z- C 11 H 22 11.45 2 Undecane C 11 H 24 11.65 3 5-Undecene Z- C 11 H 22 11.80 4 Benzene 4-ethenyl-12-dimethyl- C 10 H 12 12.65 5 1H-Indene 23-dihydro-5-methyl- C 10 H 12 12.90 6 7-Methyl-123588a-hexahydronaphthalene C 11 H 16 13.00 7 2-Methylindene C 10 H 10 13.10 8 Benzene pentyl- C 11 H 16 13.13 9 Naphthalene 1234-tetrahydro- C 10 H 12 13.25 10 Benzene 1-methylbutyl- C 11 H 16 13.38 11 Naphthalene C 10 H 8 13.75 12 3-Dodecene Z- C 12 H 24 13.90 13 Dodecane C 12 H 26 14.15 14 2-Ethyl-23-dihydro-1H-indene C 11 H 14 14.95 15 Benzene hexyl- C 12 H 18 15.55 16 Benzene 1-methylpentyl- C 12 H 18 15.70 17 2-Tridecene Z- C 13 H 26 16.30 18 Naphthalene 1-meth yl- C 11 H 10 16.35 19 Tridecane C 13 H 28 16.45 20 3-Tridecene E- C 13 H 26 16.55 21 1H-Indene 1-ethylidene- C 11 H 10 16.75 22 Benzene heptyl- C 13 H 20 17.90 23 1-Methyl-2-n-hexylbenzene C 13 H 20 18.00 24 Naphthalene 2-ethyl- C 12 H 12 18.60 25 Tetradecane C 14 H 30 18.65 26 3-Tetradecene E- C 14 H 28 19.00 27 Naphthalene 17-dimethyl- C 12 H 12 19.15 28 Pentadecane C 15 H 32 20.72 29 n-Nonylcyclohexane C 15 H 30 21.80 30 Hexadecane C 16 H 34 22.70 slide 5: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 38 TABLE 2 ALIPHATIC AROMATIC HYDROCARBONS DETECTED IN BHTT WITH THEIR RETENTION TIME NO NAME FORMULA RETENTION TIME 1 Decane C 10 H 22 9.15 2 2-Decene Z- C 10 H 20 9.32 3 Cis-3-Decene C 10 H 20 9.52 4 Benzene 123-trimethyl- C 9 H 12 9.72 5 Benzene 2-propenyl- C 9 H 10 9.82 6 Indane C 9 H 10 10.17 7 Indene C 9 H 8 10.30 8 Benzene butyl- C 10 H 14 10.52 9 Benzene 12-diethyl- C 10 H 14 10.72 10 24-Dimethylstyrene C 10 H 12 11.30 11 Undecane C 11 H 24 11.70 12 3-Undecene Z- C 11 H 22 12.05 13 Benzene 4-ethenyl-12-dimethyl- C 10 H 12 12.67 14 1H-Indene 23-dihydro-4-methyl- C 10 H 12 12.95 15 Benzene pentyl- C 11 H 16 13.15 16 Naphthalene 1234-tetrahydro- C 10 H 12 13.25 17 Benzene 1-methylbutyl- C 11 H 16 13.35 18 Azulene C 10 H 8 13.75 19 Dodecane C 12 H 26 14.15 20 6-Dodecene Z- C 12 H 24 14.25 21 3-Dodecene Z- C 12 H 24 14.50 22 Benzene hexyl- C 12 H 18 15.55 23 Benzene 1-methylpentyl- C 12 H 18 15.70 24 Naphthalene 1-methyl- C 11 H 10 16.35 25 Tridecane C 13 H 28 16.47 26 3-Tridecene E- C 13 H 26 16.57 27 1H-Indene 1-ethylidene- C 11 H 10 16.75 28 Naphthalene 2-methyl- C 11 H 10 16.85 29 1-Isopropenylnaphthalene C 13 H 12 16.95 30 Tetradecane C 14 H 30 18.65 IV. RESULTS AND DISCUSSIONS 4.1 Chemical composition of BESC: BESC was a dark and sticky liquid the compounds detected in BESC can be classified into hydrocarbons alcohols phenol ethers aldehydes ketones carboxylic acids and other esters. but large peaks of GC/MS mostly shows aromatic aliphatic and cyclic hydrocarbons while small peaks show other groups Library match used for identification of compounds based on probability score and each compound was detected very clearly and with high probability value. According to GC/MS analysis summarized in table 2 and 3 mostly aromatics and aliphatic groups were enriched in the sample. After GC/MS analysis each peak of chromatogram was matched with library one by one. 4.2 Enrichment of chemicals in CSSB sample According to GC/MS analysis summarized in Tables 1-2 C10–C16 alkanes Alkenes Cyclic hydrocarbons and aromatic hydrocarbons were enriched in the CSSB sample 4.2.1 Enrichment of C10–C16 aliphatic hydrocarbons alkane alkenes cyclic. As Table 2 and 4shows aliphatic hydrocarbons with C10–C16 are predominant in the sample with a area of 51.255 and 31.204 in BLTT and BHTT respectively slide 6: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 39 Fig.4. and Table.3 show only aliphatic hydrocarbons in BESC FIG.4. SHOWS ONLY ALIPHATIC HYDROCARBONS PEAKS TABLE 3 MAIN ALIPHATIC COMPOUNDS DETECTED IN BESC AND ITS RETENTION TIME AND FORMULAS. 4.2.2 Enrichment of aromatic hydrocarbons As Table.4 and Fig.5. show only aromatic hydrocarbons detected in BESC and also occupied large part of the BESC within the sample with a area of 24.892 and 30.008 in BHTT and BLTT respectively. FIG.5. SHOWS ONLY AROMATIC HYDROCARBONS PEAKS NO NAME FORMULA RETENTİON TİME 1 Undecane C 11 H 24 11.65 2 5-Undecene Z- C 11 H 22 11.80 3 3-Dodecene Z- C 12 H 24 13.90 4 3-Dodecene Z- C 12 H 24 14.05 5 Dodecane C 12 H 26 14.15 6 3-Dodecene E- C 12 H 24 14.25 7 3-Dodecene Z- C 12 H 24 14.50 8 2-Tridecene Z- C 13 H 26 16.30 9 Tridecane C 13 H 28 16.45 10 3-Tridecene E- C 13 H 26 16.55 11 3-Tetradecene E- C 14 H 28 18.50 12 Tetradecane C 14 H 30 18.65 13 3-Tetradecene E- C 14 H 28 19.00 14 Pentadecane C 15 H 32 20.72 15 Hexadecane C 16 H 34 22.70 slide 7: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 40 TABLE 4 MAIN AROMATIC COMPOUNDS DETECTED IN BESC AND ITS RETENTION TIME AND FORMULAS NO NAME FORMULA RETENTİON TİME 1 Benzene 4-ethenyl-12-dimethyl- C 10 H 12 12.65 2 1H-Indene 23-dihydro-5-methyl- C 10 H 12 12.90 3 7-Methyl-123588a-hexahydronaphthalene C 11 H 16 13.00 4 2-Methylindene C 10 H 10 13.10 5 Benzene pentyl- C 11 H 16 13.13 6 Naphthalene 1234-tetrahydro- C 10 H 12 13.25 7 Benzene 1-methylbutyl- C 11 H 16 13.38 8 Naphthalene C 10 H 8 13.75 9 2-Ethyl-23-dihydro-1H-indene C 11 H 14 14.95 10 Benzene hexyl- C 12 H 18 15.55 11 Benzene 1-methylpentyl- C 12 H 18 15.70 12 Naphthalene 1-methyl- C 11 H 10 16.35 13 1H-Indene 1-ethylidene- C 11 H 10 16.75 14 Benzene heptyl- C 13 H 20 17.90 15 1-Methyl-2-n-hexylbenzene C 13 H 20 18.00 16 Naphthalene 2-ethyl- C 12 H 12 18.60 17 Naphthalene 17-dimethyl- C 12 H 12 19.15 18 n-Nonylcyclohexane C 15 H 30 21.80 4.2.3 Enrichment of other compounds Alcohols Aldehydes Ketones Ethers Esters Phenols and Nitrogenous also contained some part of the BESC while in these classes Phenols and ketones were occupied more space as compared to others as shown in Table 4. TABLE 5 AREA OF DEFERENT COMPOUNDS DETECTED IN FRACTIONS BHTT BLTT OF BESC AND ITS GRAPHICAL REPRESENTATION Deferent Classes of compounds Area BHTT BLTT Alcohols n.d 0.168 Aldehydes n.d. 1.289 Ketones 9.088 6.526 Ethers 1.459 0.468 Esters 0.921 n.d. Phenols 4.018 4.458 Nitrogenous n.d. n.d. Aromatics hydrocarbons 24.892 30.008 Cyclic hydrocarbons 28.319 5.829 Aliphatic hydrocarbons 31.304 51255 slide 8: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 41 FIG.6. AREA OF COMPOUNDS IN BHTT BLUE AND B LTT RED Fig 6. Shows area of alcohols ethers ketones phenols N-compounds aliphatic aromatic and cyclic compounds in BHTT blue and BLTT red and their detail is also given in Table 5. V. CONCLUSION BESC was a dark sticky liquid which contained more than 120 compounds. Among them aromatic aliphatic and cyclic hydrocarbons especially alkanes alkenes and benzene containing compounds were dominant A laboratory scale effort is made in this work however to improve efficiency and process thus this process can be successfully applied in large-scale operations because the demand for liquid transportation fuels is increasing day by day and bio-fuels might be one of the best solutions for this problem. Technologies for converting biomass to biodiesel also are at various stages of development. Which include the pretreatment of biomass although cost of biomass may be high or the costs of processing can be high but for the time being it may be an alternative for fossil fuels Future work is going to improve the recovery of phenols ketones and other chemicals from the BESC and formulation of BESC 10 20 with normal diesel fuel to check its input and output efficiency characteristics and particulate matter PM emission. ACKNOWLEDGEMENTS This work was supported by CNPq. Brazil. REFERENCES 1 F. Mushtaq et al. / Bioresource Technology 190 2015 442–450 2 Noor et al. Stud. J. Chem. 2012 1 2 pages 76-82 3 RC Shah Z Kuamoto PM Caramão EB Machado ME et al. 2015 Bio-Oil Production by Thermal Cracking in the Presence of Hydrogen. J Fundam Renewable Energy Appl 5: 194. doi:10.4172/20904541.1000194 4 M. M. Wright D. E. Daugaard J. A. Satrio and R. C. Brown “Techno-economic analysis of biomass fast pyrolysis to transportation fuels” Fuel vol. 89 pp. 52-510 2010 5 R. Mythili P. Venkatachalam P. Subramanain and D. Uma “Characterization of bioresidues for bioil production through pyrolysis” Bioresource Technology vol. 138 pp. 71- 78 2013. 6 Murayama T. Low carbon lower buildup low smoke and efficient diesel operation with vegetable oils by conversion to mono- esters and blending with diesel oil or alcohols. SAE 1984841161:292–302. 7 Abbaszaadeh A Ghobadian B Omidkhah MR Najafi G. Current biodiesel production technologies: a comparative review Energy Convers Manage 201263:138–48. slide 9: International Journal of Engineering Research Science IJOER ISSN: 2395-6992 Vol-2 Issue-5 May- 2016 Page | 42 8 Ashraful AM Masjuki HH Kalam MA Rizwanul Fattah IM Imtenan S Shahir SA et al. Production and comparison of fuel properties engine performanceand emission characteristics of biodiesel from various non-edible vegetable oils: a review. Energy Convers Manage 201480:202–28. 9 Hoekman SK Broch A Robbins C Ceniceros E Natarajan M. Review of biodiesel composition. 10 Bagby. Vegetable oils for diesel fuel: opportunities for development. ASAE 1987:87–1588. 11 Sivalakshmi S Balusamy T. Effect of biodiesel and its blends with diethyl ether on the combustion performance and emissions from a diesel engine. Fuel 2013106:106–10. 12 Shay EG. Diesel fuel from vegetable oils: status and opportunities. Biomass Bioenergy 19934:227–42. 13 N. Özbay B. B. Uzun E. A. Varol and A. E. Pütün “Comparative analysis of pyrolysis oils and its subfractions under different atmospheric conditions” Fuel Processing Technology vol. 87 pp. 1013–1019 2006. 14 Goering E Schwab W Daugherty J Pryde H Heakin J. Fuel properties of eleven vegetable oils. Trans ASAE 198225:1472–83. 15 Pryor RW Hanna MA Schinstock JL Bashford LL. Soybean oil fuel in a small Diesel engine. Trans ASAE 198226:333–8. 16 Giannelos PN Zannikos F Stournas S Lois E Anastopoulos G. Tobacco seed oil as an alternative Diesel fuel: physical and chemical properties. Ind Crop Prod 200216:1–9. 17 Formo MW. In: Physical properties of fats and fatty acids. 4th ed. Bailey_s industrial oil and fat products Vol. 1.New York: John Wiley and Sons 1979. 18 Acaro_glu M O_guz H €OO_g€ut H. An investigation of the use of rapeseed oil in agricultural tractors as engine oil. Energy Sources 200123:823–30. 19 Diasakou M Louloudi A Papayannakos N. Kinetics of the non-catalytic transesterification of soybean oil. Fuel 199877:1297–302. 20 Adams C Peters JF Rand MC Schorer BJ Ziemke MC. Investigation of soybean oil as a Diesel fuel extender: endurance tests. JAOCS 198360:1574–9. 21 Darnoko D Cheryan M. Kinetics of palm oil transesterification in a batch reactor. JAOCS 200077:1263–7. 22 Is_ı_gıg€ur A Karaosmono_glu F Aksoy HA. Methyl ester from safflower seed oil of Turkish origin as a biofuel for Diesel engines. Appl Biochem Biotechnol 199445/46:103–12. 23 Freedman B Pryde EH. Fatty esters from vegetable oils for use as a Diesel fuel. In: Proceedings of the International Conference on Plant and Vegetable Oils as Fuels 1982. p. 17–122. 24 Fuls J Hugo FJC. On farm preparation of sunflower oil esters for fuel. In: Third International Conference On Energy Use Management 1981. p. 1595–602. 25 H. Tse et al. / Energy 83 2015 343e350 26 USEPA energy independence and security act. 2007. Available: http://www. epa.gov/otaq/fuels/renewablefuels. 27 Agarwal AK. Biofuels alcohols and biodiesel applications as fuels for internal combustion engines. Prog Energy Combust Sci 200733:233e71. 28 Demirbas A. Progress and recent trends in biofuels. Prog Energy Combust Sci 200733:1e18. 29 Kumar S Cho JH Moon Park J Moon II . Advances in diesel-alcohol blends and their effects on the performance and emissions of diesel engines. Renew Sustain Energy Rev 201322:46e72.

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