Energy & Fuels 2007, 21, 3049-3056
3049
Copyrolysis of Seyito1 mer-Lignite and Safflower Seed: Influence of the Blending Ratio and Pyrolysis Temperature on Product Yields and Oil Characterization O ¨ zlem Onay,*,† Evren Bayram,‡ and O ¨ . Mete Koc¸ kar‡ Porsuk Vocational School, Anadolu UniVersity, Eskisehir 26140, Turkey, and Department of Chemical Engineering, Anadolu UniVersity, Eskisehir 26470, Turkey ReceiVed May 4, 2007. ReVised Manuscript ReceiVed June 29, 2007
Pyrolytic behaviors of biomass/coal mixtures were investigated under a heating rate of 7 °C min-1, over a range of pyrolysis temperatures between 400 and 700 °C, and the blending ratio of coal in mixtures was varied between 0 and 100 wt %. The results indicated that considerable synergistic effects were observed during the copyrolysis in a fixed-bed reactor leading to an increase in the oil yield at lower than coal blending ratios of 33%. At the lower blending coal ratio conditions, the oil yields are higher than the expected ones, calculated as the sum of oil fractions produced by pyrolysis of each separated component. The maximum pyrolysis oil yield of 39.5% was obtained with 5% of lignite mixed with safflower seed. The obtained oils are characterized by Fourier transform infrared spectroscopy, 1H nuclear magnetic resonance, gas chromatography mass spectrometry, and elemental analysis. These findings can potentially help to understand and predict the behavior of coal/biomass blends in practical liquefaction systems.
1. Introduction Relevant advantages in the use of alternative fuels may lead to the gradual replacement of the overuse of traditional fossil fuels. The coal/biomass coprocessing is the one of the most promising options for the use of renewable fuels.1 This process allows for the consumption of fossil fuels to be reduced. The coprocessing also offers additional environmental advantages. The thermal use of biomass can contribute to the reduction of CO2 emissions, because the same amount of CO2 is extracted from the atmosphere during the growth period of the plants as is released by combustion (CO2 balance), as well as a beneficial effect on the reduction in SO2 emissions.2-3 The use of a variety of low-grade coal, as a primary energy source is becoming a subject of importance in some countries, such as Turkey, where there is a substantial reserve of such materials. In addition, great expectation exists to foster the profitable use of a great amount of low-grade coals whose accumulation, often in semiurban and urban areas, causes both social and environmental problems requiring an economically expensive solution. Unlike low-grade coal, biomass has a low ash and sulfur content, a high volatile matter yield, and fixed carbon. Therefore, it could potentially be attractive from the economical, environmental, and social points of view that lowgrade coal would be used for oil production to make use of expected synergistic effects of mixing biomass to it in a coprocessing, thus enhancing the added value of the final product.4 * To whom correspondence should be addressed. Telephone: +90-2222241389-5119. Fax: +90-222-2241390. E-mail:
[email protected]. † Porsuk Vocational School. ‡ Department of Chemical Engineering. (1) Biagini, E.; Lippi, F.; Petarca, L.; Tognotti, L. Fuel 2002, 81, 10411050. (2) Garcia-Prez, M. G.; Chaala, A.; Roy, C. Fuel 2002, 81, 893-907. (3) Rafiqul, I.; Lugang, B.; Yan, Y.; Li, T. Fuel Process. Technol. 2000, 68, 3-12.
Pyrolysis is considered one way for low-rank coal valorization because high-value gas and liquid products and good quality chars are obtained. An additional improvement of pyrolysis products can be achieved when coal is copyrolyzed together with some selected materials.5 The copyrolysis process could have potential for the environmentally friendly transformation of biomass and coal to valuable products. Consequently, the treatment and upgrading of biomass/coal is a challenge for the future. Pyrolytic processes are suitable to convert coal and biomass materials into valuable feedstock, and the specific benefits of this method potentially include the reduction of the volume of biomass, the recovery of chemicals, and the replacement of fossil fuels.6 Lignite has the biggest share, with 43% in total primary energy production in Turkey. Total lignite reserves are estimated with 8075 million tons, of which 7339 million tons are economically feasible.7 Kutahya-Seyitomer region lignite, located on western Turkey, with high ash, sulfur, and volatile matter content, could not be used as a domestic fuel without intensive cleaning. Seyitomer lignite has been mostly used in energy production in a nearby power plant, which consumes about 8 million tons of lignite annually and causes severe environmental problems.8 The geographic location of Turkey has several advantages for extensive use of most of the renewable energy sources. The annual biomass potential of Turkey is approximately 32 million (4) Pan, Y. G.; Velo, G.; Roca. X.; Manya, J. J.; Puigjaner, L. Fuel 2000, 79, 1317-1326. (5) Lazaro, M. J.; Moliner, R.; Suelves, I.; Domeno, C.; Nerin, C. J. Anal. Appl. Pyrolysis 2002, 65, 239-252. (6) Narin, N.; Colluna, S.; Sharypov, V. I.; Beregovtsova, N. G.; Baryshnikov, V.; Kutnetzov, B. N.; Cebolla, V.; Weber, J. V. J. Anal. Appl. Pyrolysis 2002, 65, 41-55. (7) Koca, H.; Koca, S.; Koc¸ kar, O. M. Miner. Eng. 2000, 13 (6), 657661. (8) Ogˇulata, R. T. Renewable Sustainable Energy ReV. 2002, 6, 471480.
10.1021/ef700230s CCC: $37.00 © 2007 American Chemical Society Published on Web 08/07/2007
3050 Energy & Fuels, Vol. 21, No. 5, 2007
tons of oil equivalents (Mtoe). The total recoverable bioenergy potential is estimated to be about 16.92 Mtoe.9 The geographic and climatic conditions of Turkey are suitable for growing field crops. On the basis of the total production of field crops (45 million tons) and oil seeds (2.5 million tons), it is estimated that 57-60 million tons of agricultural residues are produced annually in Turkey.10 Previous studies on the copyrolysis of coal with biomass had generally focused on the impact of synergistic effects (i.e., chemical interaction between the two fuels) on the yield of pyrolysis products11-16 and the influence of synergistic effects on the composition of the pyrolysis products.2,5-6,17-27 In this study, investigations into the product yields during copyrolysis of coal/biomass blends prepared at different ratios have been conducted using a fixed-bed pyrolysis reactor. The effects of the blend ratio for pyrolysis of lignite/safflower seed and the final pyrolysis temperature on the pyrolysis product yield and mixture composition on the chemical compositions of the oil have been investigated. 2. Experimental Section 2.1. Materials. The safflower seed (Carthamus tinctorius L.) and lignite sample investigated in this study has been taken from the vicinity of the Eskisehir and Ku¨tahya-Seyito¨mer regions, located in central Anatolia, respectively. Prior to use, the sample was air-dried and grounded in a high-speed rotary cutting mill. The particle size range was between 0.5 and 1.0 mm for lignite and 0.6-0.85 mm for safflower seed. Some characteristics of the used safflower seed and lignite are given in Table 1. 2.2. Thermogravimetric (TG) Analysis. TG analysis was carried out in a LINSEIS Thermowaage L81 thermogravimetric analyzer coupled with a differential thermal analyzer (DTA). The initial weight of the sample was close to 25 mg. The samples were heated from room temperature to 800 °C with a heating rate of 5 °C min-1 using N2 as the carrier gas at a constant flow rate of 40 mL min-1. 2.3. Copyrolysis in a Fixed-Bed Reactor. Safflower seed, lignite, and their mixtures were pyrolyzed in a Heinze retort. The 316 stainless-steel reactor used previously has a volume of 250 mL and was externally heated by an electric furnace, with the temperature being controlled by a thermocouple inside the bed.28-31 (9) Balat, M. Biomass Bioenergy 2005, 29, 32-41. (10) www.fao.org/docrep/. (11) Vuthaluru, H. B. Fuel Process. Technol. 2003, 85, 141-155. (12) Vuthaluru, H. B. Bioresour. Technol. 2004, 92, 187-195. (13) Cordero, T.; Rodriguez-Mirasol, J.; Pastrana, J.; Rodriguez, J. J. Fuel 2004, 83, 1585-1590. (14) Moghtaderi, B.; Meesri, C.; Wall, T. F. Fuel 2004, 83, 745-750. (15) Pan, Y. G.; Velo, G.; Puigjaner, L. Fuel 1996, 75, 412-418. (16) Haykiri-Acma, H.; Yaman, S. Fuel 2007, 86, 373-380. (17) Suelves, I.; Moliner, R.; Lazaro, M. J. J. Anal. Appl. Pyrolysis 2000, 55, 29-41. (18) Meesri, C.; Moghtaderi, B. Biomass Bioenergy 2002, 23 (1), 5566. (19) Sharypov, V. I.; Narin, N.; Beregovtsova, N. G.; Baryshnikov, S. V.; Kuznetsov, B. N.; Cebolla, V. L.; Weber, J. V. J. Anal. Appl. Pyrolysis 2002, 64, 15-28. (20) Sharypov, V. I.; Beregovtsova, N. G.; Kuznetsov, B. N.; Membrado, L.; Cebolla, V. L.; Narin, N.; Weber, J. V. J. Anal. Appl. Pyrolysis 2003, 67, 325-340. (21) Sharypov, V. I.; Beregovtsova, N. G.; Kuznetsov, B. N.; Baryshnikov, S. V.; Cebolla, V. L.; Weber, J. V.; Collura, S.; Finqueneisel, G.; Zimny, T. J. Anal. Appl. Pyrolysis 2006, 76, 265-270. (22) Zhang, L.; Xu, S.; Zhao, W.; Shuqin, L. Fuel 2007, 86, 353-359. (23) Artok, L.; Schobert, H. H.; Nomura, M.; Erbatur, O.; Kidena, K. Energy Fuels 1998, 12, 1200-1211. (24) Ballice, L. Energy Fuels 2001, 15, 659-665. (25) Ballice, L.; Reimert, R. J. Anal. Appl. Pyrolysis 2002, 65, 207219. (26) Ballice, L. Oil Shale 2002, 19, 57-73. (27) Ballice, L. Oil Shale 2002, 19, 127-141. (28) Onay, O ¨ .; Koc¸ kar, O ¨ . M. Biomass Bioenergy 2004, 26, 289-299.
Onay et al. Table 1. Main Characteristics of the Safflower Seed and Lignite characteristics proximate analysis (wt %, as received) moisture volatile fixed C ash elemental analysis (wt %, daf basis) carbon hydrogen nitrogen sulphur oxygena H/C component analysis (wt %, as received) extractivesb hemicellulosec ligninc cellulosec calorific value (MJ/kg) a
lignite
safflower seed
11.2 32.7 16.5 39.6
5.7 80.8 11.3 2.2
36.8 3.4 1.1 1.8 56.9 1.11
61.1 9.2 2.8
6.6
26.9 1.81 33.3 18.6 28.9 27.2 26.8
By difference. b Benzene/alcohol (2:1) (v/v). c Extractive free basis.
The experiments performed in the Heinze reactor were carried out in two groups. In the first, to determine the effect of the pyrolysis temperature on the product yields, 10 g of air-dried sample was placed in the reactor and the temperature was raised at 7 °C min-1 to a final temperature of either 450, 500, 550, or 700 °C and held for either a minimum of 30 min or until no further significant release of gas was observed. The flow of gas released was measured using a soap film for the duration of the experiments. The liquid phase was collected in a glass liner located in a cold trap maintained at about 0 °C. The liquid phase consisted of aqueous and oil phases, which were separated and weighed. After pyrolysis, the solid char was removed and weighed, and then the gas yield was calculated by the difference. For these group experiments, to determine the effect of the pyrolysis temperature on the product yields, the blending ratios (weight of coal in the blend expressed as a percentage of the total sample weight) were used, either 0, 33, 50, 66, or 100% (w/w). In the second, for the effect of the blending ratio on the pyrolysis yields, experiments were conducted at a range of blending ratios between 0, 3, 5, 7, 10, 33, 50, and 100% (w/w). For all of these experiments, the final pyrolysis temperature was taken as 550 °C based on the first group of the experiments. In this study, all of the yields are expressed on a dry ash-free (daf) basis with the average yields of at least three experiments within the experimental error of less than (0.5%. 2.4. Characterization. The oils analyzed in this study have been obtained in the experimental condition that has given a maximum oil yield. A CHNS-O Fisions, EA 1108 instrument was used to determine the elemental composition of the samples. The calorific value of the samples was determined [American Society for Testing and Materials (ASTM) 3286]. The values reported are the gross heat of combustion at a constant volume. The IR spectrum of the oil was made using a Perkin-Elmer Fourier transform infrared (FTIR) spectrometer spectrum 2000. The 1H nuclear magnetic resonance (NMR) of the oils was obtained at a H frequency of 500 MHz using a Bruker BioSpin GmbH instrument. The sample was dissolved in chloroform-d. Liquid column chromatography was used to fractionate the pyrolysis oils into chemical class compositions. First, the pyrolysis oils were separated into two fractions, as n-pentane-soluble and -insoluble compounds (asphaltenes), by using n-pentane. The n-pentane-soluble material was further separated on activated silicagel (70-230 mesh). The column was eluted successively with n-pentane, toluene, and methanol to produce aliphatic, aromatic, (29) Koc¸ kar, O ¨ . M.; Onay, O ¨ .; Pu¨tu¨n, A. E.; Pu¨tu¨n, E. Energy Sources 2000, 22 (10), 913-924. (30) Beis, S. H.; Du¨zenli, D.; Onay, O ¨ .; Koc¸ kar, O ¨ . M. Energy Sources 2003, 25, 1053-1062. (31) Onay, O ¨ .; Koc¸ kar, O ¨ . M. Energy Sources 2003, 25, 879-892.
Copyrolysis of Seyito¨mer-Lignite and Safflower Seed
Energy & Fuels, Vol. 21, No. 5, 2007 3051
Figure 1. Percent residual mass versus the temperature for raw materials and coal/biomass blends.
and polar fractions, respectively. Each fraction was dried, weighed, and then subjected to elemental and FTIR analyses. Only the n-pentane fractions of the bio-oils were subjected to gas chromatography mass spectrometry (GC/MS) analyses. GC/MS analyses were performed using a HP 6890 GC/MS (30 m × 0.25 mm i.d.; 0.25 µm film thickness, HP-5MS column). Helium was used as a carrier gas at a constant flow of 1.2 mL. The GC oven temperature was programmed from 50 to 280 °C at 10 °C min-1 and held at 280 °C for 10 min. Typical operating conditions were ionization energy, 70 eV; ion source temperature, 230 °C; and scans per second over mass range electron (m/z), 40-500.
Figure 2. Effects of the pyrolysis temperature on the char yield.
3. Results and Discussion 3.1. Thermogravimetric Analysis. The individual curves for each raw material and coal/biomass blends are presented in Figure 1. Percent residual mass decreased with an increasing biomass content for blends of coal/biomass. This trend is due to the high volatile content and low fixed carbon content in the biomass sample compared to the coal. The striking difference is also attributed to the difference in the strength of the molecular structure of fuels. The polymers of cellulose, hemicellulose, and lignin, which constitute the macromolecular structure of the biomass are linked together with relatively weak ether bonds (R-O-R). These bonds are less resistant to the heat at low temperature (400-500 °C). In contrast, the immobile phase present in the coal structure, which mostly comprises dense polycylic aromatic hydrocarbons linked together by CdC (aromatic ring) bonds, are more resistant to the heat. Therefore, when the coal content is increased in the blend, the volatile content decreases and fixed carbon increases.12 Biomass and coal are essentially degraded at different ranges of temperature. An important amount of biomass char has already been formed when the major part of coal is decomposing. The biomass sample curve shows a sharp branch where the larger weight loss takes places within a relatively narrow temperature range that with some slight differences extends from about 200 to around 420 °C. After this sharp branch, the TG curve for biomass shows a smooth region, where a continuous weight-loss substantially lower quantitative significance is observed. The residual weight loss within the 500-800 °C temperature range is fairly low, and thus, 500-550 °C can be a practical temperature to carry out the pyrolysis of biomass. For safflower seed, the devolatilization starts at 200 °C and the weight loss at the final pyrolysis temperature (800 °C) is 82.8%. The coal tested starts to devolatilize at a higher temperature compared to biomasses. The coal has a peak between 340 and 530 °C. The global weight loss at the final pyrolysis temperature of 800 °C is 35.8%.
Figure 3. Effects of the pyrolysis temperature on the oil yield.
TG analysis has been conducted also for the coal/biomass blends prepared. The corresponding residual mass curves are reported in Figure 1 as a function of the temperature. The curve for each blend lies between the curves of the reference materials. Further, two different steps of devolatilization may be observed: one at lower temperatures (imputable to the biomass degradation) and another at higher temperatures (imputable to the coal degradation). 3.2. Influence of the Pyrolysis Temperature. The influence of the pyrolysis temperature on the product yields obtained from pyrolysis of coal/biomass blends are shown in Figures 2 and 3 for a range of blending ratios between 0 and 100%. As shown in Figure 2, the char yield significantly decreased as the final pyrolysis temperature was raised from 450 to 700 °C for each blending ratio. In other words, the pyrolysis conversion increased. The decrease in the char yield with an increasing temperature could be due to a greater decomposition of the samples at higher temperatures. Figure 3 represents the production characteristics of oil from the blended materials in the temperature range of 450-700 °C. In the range investigated, the temperature seems to have the same impacts on both parent materials and their investigated blends because they exhibit similar characteristics. However, it is obvious that the variation degree of the product yield from biomass is larger than that of coal. For biomass and blended
3052 Energy & Fuels, Vol. 21, No. 5, 2007
Onay et al. Table 2. Elemental Compositions and Calorific Values of Pyrolysis Oils elemental analysisa C H N S Ob H/C molar ratio calorific value (MJ kg-1) a
Figure 4. Effects of the blending ratio of coal and safflower seed on the production of the copyrolysis products at a pyrolysis temperature of 550 °C. The dashed lines represent the sum of fractions produced by the pyrolysis of lignite and safflower seed.
materials, the oil yield increased as the final pyrolysis temperature was raised from 450 to 550 °C, reaching a maximum at a pyrolysis temperature of 550 °C, and decreased at the pyrolysis temperature of 700 °C. In addition, the amounts of oil obtained from coal/biomass blends seem to be proportional to the blending ratio. To verify the existence of the synergistic effects, the yield of pyrolysis products were plotted against the blending ratio at 550 °C, in Figure 4. The presence of the interaction between the species forming the volatile mixture may be in part due to the fact that the molecular structure of coal and biomass are constituted from cognate carbon-molecular frameworks. When coal starts to soften, molecular fragmentation produces the release of smaller molecules caged in the coal micropores, which are hydrogenrich donor species. They tend to take part in the recapping of free radicals from thermal decomposition and to convert them into stabilized hydrocarbon molecules. As the pyrolysis temperature increases, an increase in the production of radical fragments takes place, together with an increase in the fluidity.
Figure 5. IR spectra of the pyrolysis oils.
coal
5% coal
10% coal
biomass
80.1 11.2 0.5 0.6 7.6 1.68 41.9
74.7 11.8 1.6
73.4 10.9 1.3
72.5 11.3 1.5
11.9 1.90 40.2
14.4 1.78 37.96
14.7 1.87 38.2
Weight percentage on a dry ash-free basis. b By difference.
If these radicals are highly reactive and they are not stabilized by hydrogen-transfer reactions, they may recombine with other molecules, and then, a viscous (low-fluidity) system is formed.32 As a result, active radicals are produced from both fuels during the depolymerization of the parent structures. As pointed out before, these radicals consist mainly of hydrogen donor and acceptor compounds. There are external hydrogen donors or other reactive/catalytic agents to interfere with the chain radical processes between the coal and biomass radicals; chemical interactions are therefore observed.18 3.3. Influence of the Coal/Biomass Composition. The influence of the coal/biomass composition on the copyrolysis product yield was investigated at 550 °C. The productions of char, oil, and gas yields were plotted against the blending ratio in Figure 4. It can be seen that the yields of both conversion and oil increase with the biomass ratio. The gas yield was not significantly affected until the coal ratio in the feedstock decreased to 10 wt %. The amount of gases obtained was slightly lower than expected. The maximum yield of oil is obtained for the 5% blending ratio of coal (39.5%). In this blending ratio, the yield of char decreases by more than 10% and that of oil increases by about 17%, respectively, compared to the expected ones (dashed line in Figure 4) calculated as the sum of oil fractions produced by the pyrolysis of lignite and safflower seed. Therefore, it is obvious that there are noticeable synergies that occur under the lower blending ratio conditions. This may be due to the fact that enough quantity of biomass in the blends is needed to offer plenty of hydrogen donors and play a role in hydrogenation. The mineral matter present in the coal may also act as a catalyst in the copyrolysis reactions. Thus, the
Copyrolysis of Seyito¨mer-Lignite and Safflower Seed
Energy & Fuels, Vol. 21, No. 5, 2007 3053
Figure 6. Proton NMR spectra of the pyrolysis oils. Table 3. 1H NMR Results of Pyrolysis Oils sample (percent in weight) hydrogen environment
range (ppm)
biomass
5% coal
10% coal
coal
aromatic alkene aliphatic adjacent to oxygen aliphatic adjacent to aromatic alkene group other aliphatic (bonded to aliphatic only)
6.3-9.3 4.5-6.3 3.3-4.5 1.8-3.3 0.4-1.8
6.0 14.9 4.4 24.2 50.5
10.2 2.5 2.7 23.6 61.0
11.1 3.2 3.5 24.2 58.0
14.8 0.6 0.8 21.3 62.5
coprocessing may generate different products (mainly liquid) under atmospheric conditions.22,33 3.4. Chemical Composition. The properties of oils are given in Table 2. As it can be seen in Tables 1 and 2, oils contain less amounts of oxygen content than that of the original feedstock. The significant decrease in oxygen content of the oil compared to the original feedstock is important, because the high oxygen content is not attractive for the production of transport fuels. A further comparison of H/C ratios with conventional fuels indicates that H/C ratios of the oils obtained in this study lie between those of light and heavy petroleum products. It can be seen in Table 2 that the oxygen content of the oil for the 10% blending ratio of coal is 14.4%. It fell to 11.9% for the 5% blending ratio of coal copyrolysis conditions. Clearly, the role of the 5% blending ratio of coal at the copyrolysis conditions in removing the oxygen from the biomass-derived pyrolysis oils is evident from the much reduced oxygen content of the oils. Functional group compositional analysis was determined by FTIR spectrometry, and results are shown in Figure 5.The O-H stretching vibrations between 3200 and 3400 cm-1 indicate the presence of phenols and alcohols. The C-H stretching vibrations between 2800 and 3000 cm-1 and C-H deformation vibrations between 1350 and 1475 cm-1 indicate the presence of alkanes. The CdO stretching vibrations with absorbance between 1650 and 1750 cm-1 indicate the presence of ketones or aldehydes. The absorbance peaks between 1575 and 1675 cm-1 represent CdC stretching vibrations indicative of alkenes and aromatics. The 1H NMR spectra of the oils and hydrogen distributions are given in Figure 6 and Table 3, respectively. Results of the 1H NMR analysis show that the oils mainly contain aliphatic
protons at carbon atoms bonded to other aliphatic carbon atoms. The amount of olefinic and aliphatic protons adjacent to oxygen decreased with copyrolysis. On the contrary, the copyrolysis oils contained a greater concentration of single-ring aromatic compounds and aliphatic group rings than biomass pyrolysis oil. All of the bio-oils were separated into two fractions, as n-pentane-soluble and -insoluble compounds, by using npentane. The n-pentane-soluble materials were further separated by adsorption chromatography as aliphatic, aromatic, and polar fractions. The overall results are presented in Figure 7. The deasphalted oil obtained from the pyrolysis of biomass is 13%; it increased to a level of 15-18% with copyrolysis. The aliphatic and aromatic fractions were 34.4 and 33.3% in biomass pyrolysis and increased to 39 and 42.4% at the copyrolysis oil obtained with 5% of lignite mixed with biomass, respectively. The polar
Figure 7. Liquid column chromatography of the pyrolysis oils.
3054 Energy & Fuels, Vol. 21, No. 5, 2007
Onay et al.
Figure 8. GC/MS of the n-pentane fraction for (a) coal, (b) 5% coal, (c) 10% coal, and (d) biomass pyrolysis oils.
fraction of 32% in the biomass pyrolysis oil decreased to 18.6% with copyrolysis (5% coal). This is also consistent with the results of the elemental analysis. The GC/MS analysis of the n-pentane subfractions given in Figure 8 illustrates the distribution of the products obtained from the copyrolysis of coal, 5% coal, 10% coal, and biomass. The abundances of the products are listed and compared in Table 4 as the area (%) related to the total ion intensity. The product assignment is based on the mass spectra (using Wiley 275 library). The straight chain n-alkanes range from C17 to C30 for coal, C10 to C17 for biomass, and C10 to C31 for coal/biomass in the pyrolysis oils. It can be easily seen from Table 4 that the total amount of heptadecane and 8-heptadecene increases with the increasing blending ratio of biomass in raw materials. Coal (32) Ishaq, M.; Ahmad, I.; Shakirullah, M.; Khan, M. A.; Rehman, H.; Bahader, A. Energy ConVers. Manage. 2006, 47 (18-19), 3216-3223. (33) Ahmaruzzaman, M.; Sharma, D. K. Energy Fuels 2007, 21, 891897.
addition has a marked impact on both the degradation mechanism and product distribution. According to the GC/MS investigation, the copyrolysis products contained the higher amount of relatively heavy hydrocarbons as compared to biomass pyrolysis products. The oils from the mixture of 5 and 10% coal have a remarkable distribution; benzene, pentadecane, 8-heptadecene, heptadecane, tetracosane, hexacosane, and docasene represent more than 29% of all of the liquids of the fraction. The synergistic effect between the species forming the volatile mixture may be in part due to the fact that the macromolecular structures of coal and biomass are constituted from carbonmolecular frameworks. 4. Conclusion In the present work, the copyrolysis of safflower seed with lignite was performed in a Heinze retort and the effects of the
Copyrolysis of Seyito¨mer-Lignite and Safflower Seed
Energy & Fuels, Vol. 21, No. 5, 2007 3055
Table 4. Identification and Yield (Area %) of Pyrolysis Oils area (%) retention time (min)
products
4.25 4.63 4.73 5.42 5.57 6.15 6.55 7.01 7.15 7.45 7.57 8.44 8.55 8.84 8.95 9.20 9.56 9.69 9.84 9.92 10.17 10.28 10.34 10.42 10.65 10.74 10.86 11.00 11.06 11.16 11.22 11.36 11.43 11.53 11.66 11.70 11.82 11.99 12.18 12.22 12.42 12.46 12.54 12.63 12.72 12.81 13.22 13.25 13.37 13.61 13.85 14.00 14.19 14.44 14.48 14.53 14.69 14.74 14.79 14.85 14.92 14.96 15.82 15.88 15.94 16.87 16.92
benzene, 1-ethyl-3-methylcyclopropane, 1-hexyl-2-methyldecane benzene butylbenzene undecane 5-undecene benzene, pentylbenzene, (1-methylbutyl)2-dodecene, (Z)dodecane benzene, hexylbenzene, (1,3-dimethylbutyl)1-tridecene tridecane naphthalene, 1-methylbenzene, 1,2,4,5-tetramethylbenzene, 1-methyl-3-hexylbenzene, heptyl1-methyl-2-N1-tetradecene tetradecane 5-tetradecane naphthalene, 2,7-dimethylnaphthalene, 2,3-dimethylbenzene, 2-heptenyl-, (Z)naphthalene, 1,5-dimethylacenaphthylene naphthalene, 1,7-dimethylbenzene, octylp-tolylethylamine 1-hexadecanol 1-pentadecene pentadecane naphthalene, 2-(1-methylethyl)aristolen dibenzofuran 1,4,6-trimethylnaphthalene n-nonylcyclohexane naphthalene, 2,3,6-trimethylbenzene, nonyl5-dodecyne 7-hexadecene, (Z)3-hexadecene, (Z)hexadecane benzene, (1-methylnonyl)dibenzofuran, 4-methyl7-octadecyne, 2-methylcyclodecene 8-heptadecene heptadecane benzene, (1-methyldecyl)3-tetradecene, (Z)benzene, methyl(1-methylethyl)6(Z),9(E)-heptadecadiene cyclohexane, undecyltricyclo[3.3.1.1(3,7)]decane, 2-nibenzene, undecylbenzene, (1,3-dimethylbutyl)1-octadecene octadecane phenanthrene benzene, dodecyl1-nonadecene nonadecane 1-octadecene eicosane
coal
0.31
5% coal
10% coal
biomass
0.46 0.96
2.01 0.85 1.75
2.06 1.94 0.51 3.56 0.83 1.31 0.95 1.61 0.99 0.90 1.52
2.68 3.14 1.11 4.25 0.99 1.54 1.64 2.82 1.22 1.15 1.37
0.44 0.41 1.20 0.47 1.34 1.62 0.31
0.82 0.53 2.05 0.59 1.01 1.46
3.88 1.09 6.92 0.99 3.74 1.25 0.95 0.92 3.92 1.02 0.82 2.36 0.62 2.01 0.88
0.22
0.33
0.88
0.44
0.54
1.37
0.89 0.64 1.28 0.82 3.52
1.20 0.72 1.27 0.95 2.94
1.40 0.73 1.16 1.49 2.05
0.47
0.62
0.77
0.70
0.76
1.11
1.06 1.13 1.29 0.87 1.15 0.68
1.31 1.26 1.49 1.13 1.43 1.04
2.48 2.85 1.37 1.94 1.03 0.71
0.47 2.85 7.57 1.47 1.28 0.45 0.68 0.35
0.56 0.66 1.66 9.59 2.40 1.65 0.94 0.91 0.74
0.54 0.64 3.77 10.57 1.68 1.42 1.24 1.20
0.45 0.52 0.22 0.35
0.85 0.94 0.43 0.64
0.19 0.44 0.24 0.44
0.27 0.55 0.21 0.43
0.81 1.02
1.52 0.83 0.62 0.65
0.50 0.73 0.66 1.95 2.41 2.69 0.99
2.59 1.54 1.25 0.70 0.63 2.20 0.69 1.78 0.52 0.76 0.36 0.37 0.38 1.89 2.16 0.59 0.51 0.88 1.83 0.87 1.95
0.51 0.68 0.77 0.46
0.29
3056 Energy & Fuels, Vol. 21, No. 5, 2007
Onay et al. Table 4. Continued area (%)
retention time (min)
products
coal
17.11 17.81 17.86 18.71 18.76 19.58 19.63 20.42 20.48 21.25 21.82 22.02 22.21 22.58 22.77 22.94 23.51 23.721 24.35 24.64 25.33 25.61 25.96 26.24 26.50 26.68
3-eicosene 10-heneicosene heneicosane 1-nonadecene n-docosane 1-docosene nonadecane 1-nonadecene tetracosane pentacosane docosane hexacosane 9-hexacosane tricosane docasene benzene, eicosyloctacosane 1-hexacosane nonacosane cholestan-6-one triacontane bikaverin 3-chloro-7-methyl-10,11-diphenyldi9R-hydroxy-5R-cholestoctacosane 2,8-diisopropyl-peri-xanthenoxanth-
0.32 0.89 2.89 0.85 3.33 0.88 3.21 0.78 6.27 5.97 1.72 6.13 0.89 1.63 5.74 0.65 7.22 0.88 3.79 0.51 2.41
blending ratio and pyrolysis temperature on synergy were investigated. The maximum yields of oils are obtained at a pyrolysis temperature of 550 °C. At this temperature, the most important parameter for the oil production is the blending ratio in feedstocks. The results showed that the oil yields increased compared to the expected ones for the experiments with coal less than 20% and additive phenomena occur, leading to a higher oil production. The maximum degree of synergetic effects on
1.12
5% coal
10% coal
biomass
0.76
0.19 0.67
0.33
0.96 0.54 1.81 0.53 4.85 0.87 0.84 3.79 1.02 2.94 1.27 2.15 0.46 0.75 0.65 1.05 0.62 0.59 0.78 0.50 2.80
0.85 0.17 0.84
0.31
2.58 1.14
2.02 0.65
1.35
0.68
1.23
0.64
1.37
0.53
1.25
0.51
0.66 0.59 1.66 1.48 0.62 2.58
0.45
0.95 0.91 0.53 4.05
the oil yields was observed at a blending ratio of 5% in the copyrolysis of the lignite and safflower seed. Acknowledgment. The authors express their thanks to the Anadolu University Scientific Research Projects Commission (project number 031803) for the financial support that made this work possible. EF700230S
