Journal of Fuels The latest articles from Hindawi Publishing Corporation © 2014 , Hindawi Publishing Corporation . All rights reserved. Evaluation of Thermal Evolution Profiles and Estimation of Kinetic Parameters for Pyrolysis of Coal/Corn Stover Blends Using Thermogravimetric Analysis Wed, 19 Mar 2014 13:29:49 +0000 The thermal evolution profiles and kinetic parameters for the pyrolysis of two Montana coals (DECS-38 subbituminous coal and DECS-25 lignite coal), one biomass sample (corn stover), and their blends (10%, 20%, and 30% by weight of corn stover) have been investigated at a heating rate of 5°C/min in an inert nitrogen atmosphere, using thermogravimetric analysis. The thermal evolution profiles of subbituminous coal and lignite coal display only one major peak over a wide temperature distribution, ~152–814°C and ~175–818°C, respectively, whereas the thermal decomposition profile for corn stover falls in a much narrower band than that of the coals, ~226–608°C. The nonlinearity in the evolution of volatile matter with increasing percentage of corn stover in the blends verifies the possibility of synergistic behavior in the blends with subbituminous coal where deviations from the predicted yield ranging between 2% and 7% were observed whereas very little deviations (1%–3%) from predicted yield were observed in blends with lignite indicating no significant interactions with corn stover. In addition, a single first-order reaction model using the Coats-Redfern approximation was utilized to predict the kinetic parameters of the pyrolysis reaction. The kinetic analysis indicated that each thermal evolution profile may be represented as a single first-order reaction. Three temperature regimes were identified for each of the coals while corn stover and the blends were analyzed using two and four temperature regimes, respectively. Abhijit Bhagavatula, Gerald Huffman, Naresh Shah, and Rick Honaker Copyright © 2014 Abhijit Bhagavatula et al. All rights reserved. Separate Determination of Borohydride, Borate, Hydroxide, and Carbonate in the Borohydride Fuel Cell by Acid-Base and Iodometric Potentiometric Titration Wed, 29 Jan 2014 09:11:15 +0000 A methodology for quantitative chemical analysis of the complex “borohydride-borate-hydroxide-carbonate-water” mixtures used as fuel in the borohydride fuel cell was developed and optimized. The methodology includes the combined usage of the acid-base and iodometric titration methods. The acid-base titration method, which simultaneously uses the technique of differentiation and computer simulation of titration curves, allows one to determine the contents of hydroxide (alkali), carbonate, and total “borate + borohydride” content. The iodometric titration method allows one to selectively determine borohydride, so the content of each of , , , and anions in the fuel becomes estimated. The average determination error depends on the number and ratio of compounds in a mixture. Specific details of the analysis of various fuel mixtures are discussed. A. V. Churikov, S. L. Shmakov, V. O. Romanova, K. V. Zapsis, A. V. Ushakov, A. V. Ivanishchev, and M. A. Churikov Copyright © 2014 A. V. Churikov et al. All rights reserved. Compatibility Studies on Elastomers and Polymers with Ethanol Blended Gasoline Wed, 29 Jan 2014 00:00:00 +0000 This paper reports the compatibility studies of 10% ethanol blended gasoline (E10) with four types of elastomer materials, namely, Neoprene rubber, Nitrile rubber, hydrogenated Nitrile butadiene rubber (HNBR), and Polyvinyl chloride/Nitrile butadiene rubber blend (PVC/NBR), and two types of plastic materials, namely, Nylon-66 and Polyoxymethylene (Delrin). These materials have applications in automotives as engine seals, gaskets, fuel system seals and hoses, and so forth. Two types of the ethanol blended gasoline mixtures were used: (a) gasoline containing 5% ethanol (E5), which is commercial form of gasoline available in India, and (b) gasoline containing 10% ethanol (E10). The above materials were immersed in E5 and E10 for 500 hrs at 55°C. A set of eight different properties in E5 and E10 (visual inspection, weight change, volume change, tensile strength, percent elongation, flexural strength, impact strength, and hardness) were measured after completion of 500 hrs and compared with reference specimens (specimens at 55°C without fuel and specimens at ambient conditions). Variation observed in different materials with respect to the above eight properties has been used to draw inference about the compatibility of these elastomeric/polymer materials with E10 fuel vis-à-vis E5 fuels. The data presented in this study is comparative in nature between the results of E10 and E5. J. S. Dhaliwal, M. S. Negi, G. S. Kapur, and Shashi Kant Copyright © 2014 J. S. Dhaliwal et al. All rights reserved. Effect of Selected Metal Contaminants on the Stability of Castor Oil Methyl Ester Tue, 28 Jan 2014 07:28:48 +0000 This study investigates the effect of iron (Fe) and aluminium (Al) contaminants on the stability of castor oil methyl ester (COME). COME was synthesized via transesterification reaction and the peroxide value of the COME was used to monitor its stability. Varied amounts of Fe and Al (0.2 g, 0.4 g, 0.6 g, 0.8 g, and 1.0 g) in powdered form were added to 100 mL of COME and their effect on the peroxide value was monitored for a day, for the first phase of the experiment, while for the second phase, 0.3 g and 0.8 g of these metals were added to 100 mL COME, and their effect was monitored for 9 days. At the end of the study, it was observed that as the amount of the metals added to the COME increases from 0.2 to 1.0 g/100 mL COME, the peroxide values of the COME decrease from 1.6 to 0.3 meq/kg and 1.2 to 0.3–0.2 meq/kg for Al and Fe contaminated COME after 24 h. Also in the second phase of the experiment, the peroxide value of the 0.3 g Fe metal contaminated COME increased from 1.4 to 11.6 meq/kg while that of 0.8 g Fe contaminated COME increased from 1.4 to 3.0 meq/kg after the nine-day period of investigation. Christopher E. Akhabue, John C. Iworah, and Felix A. Aisien Copyright © 2014 Christopher E. Akhabue et al. All rights reserved. Density, Viscosity and Water Phase Stability of 1-Butanol-Gasoline Blends Mon, 27 Jan 2014 07:45:23 +0000 The aim of this work was to describe the density and viscosity and water tolerance of 1-butanol-gasoline blends. Density and viscosity of 1-butanol are higher than that for gasoline and they can affect these parameters in the final gasoline blend. Density increases linearly and viscosity exponentially with the content of 1-butanol. Water solubility in 1-butanol-gasoline blend was determined as the temperature of a phase separation. The water was separated in the solid form at negative temperature and the phase separation point was determined as the temperature of crystallization. Influence of ethanol and ethers used for gasoline blending on water phase stability of 1-butanol-gasoline blend was studied. Ethers are slightly miscible with water and they improve the phase stability. While ethanol is completely miscible water and increases the water solubility in the blends. Finally, water extractions of both alcohols from gasoline were done. In contrast to the ethanol-gasoline blends, 1-butanol remained in the hydrocarbon phase. Zlata Mužíková, Pavel Šimáček, Milan Pospíšil, and Gustav Šebor Copyright © 2014 Zlata Mužíková et al. All rights reserved. Propane Fuel Cells: Selectivity for Partial or Complete Reaction Mon, 20 Jan 2014 12:35:58 +0000 The use of propane fuel in high temperature (120°C) polymer electrolyte membrane (PEM) fuel cells that do not require a platinum group metal catalyst is being investigated in our laboratory. Density functional theory (DFT) was used to determine propane adsorption energies, desorption energies, and transition state energies for both dehydrogenation and hydroxylation reactions on a Ni(100) anode catalyst surface. The Boltzmann factor for the hydroxylation of a propyl species to form propanol and its subsequent desorption was compared to that for the dehydrogenation of a propyl species. The large ratio of the respective Boltzmann factors indicated that the formation of a completely reacted product (carbon dioxide) is much more likely than the formation of partially reacted products (alcohols, aldehydes, carboxylic acids, and carbon monoxide). That finding is evidence for the major proportion of the chemical energy of the propane fuel being converted to either electrical or thermal energy in the fuel cell rather than remaining unused when partially reacted species are formed. Shadi Vafaeyan, Alain St-Amant, and Marten Ternan Copyright © 2014 Shadi Vafaeyan et al. All rights reserved. Statistical Optimization of Fermentation Process Parameters by Taguchi Orthogonal Array Design for Improved Bioethanol Production Tue, 14 Jan 2014 09:42:27 +0000 The statistical optimization of different fermentation process parameters in SSF of mixed MAA and organosolv pretreated 1% (w v−1) wild grass, namely, recombinant Clostridium thermocellum hydrolytic enzymes’ volume (GH5 cellulase, GH43 hemicellulase), fermentative microbes’ inoculum volume (Saccharomyces cerevisiae, Candida shehatae), pH, and temperature, was accomplished by Taguchi orthogonal array design. The optimized parameters in 100 mL of fermentation medium were (%, v v−1) as follows: 1.0, recombinant GH5 cellulase (5.7 mg−1, 0.45 mg mL−1); 2.0, recombinant GH43 hemicellulase (3.7 U mg−1, 0.32 mg mL−1); 1.5, S. cerevisiae (3.9 × 108 cells mL−1); 0.25, C. shehatae (2.7 × 107 cells mL−1); pH, 4.3; and temperature, 35∘C. pH with p-value 0.001 was found to be the most significant factor affecting SSF. The ethanol titre obtained in Taguchi optimized shake flask SSF was 2.0 g L−1 implying a 1.3-fold increase as compared to ethanol titre of 1.5 g L−1 in unoptimized shake flask SSF. A 1.5-fold gain in ethanol titre (3.1 g L−1) was obtained with the same substrate concentration in lab scale bioreactor on scaling up the shake flask SSF with Taguchi optimized process parameters. Saprativ P. Das, Debasish Das, and Arun Goyal Copyright © 2014 Saprativ P. Das et al. All rights reserved. Facile Route to Generate Fuel Oil via Catalytic Pyrolysis of Waste Polypropylene Bags: Towards Waste Management of >20  Plastic Bags Thu, 02 Jan 2014 09:39:53 +0000 A novel strategy of waste recycling of polypropylene plastics (PP) bags for generation of commercially viable byproducts using nanoforms of nickel as catalyst is presented in this work. After pyrolysis of waste PP bags (>20 μm) under continuous argon flow, 90% conversion efficiency to high petroleum oil was observed at 550°C. To assess the physicochemical attributes of formed oil, flash point, pour point, viscosity, specific gravity, heating value, and density were also measured and found to be very close to ideal values of commercial fuel oil. Moreover, GC-MS was used to resolve the range of trace mass hydrocarbon present in the liquefied hydrocarbon. Our robust recycling system can be exploited as economical technique to solve the nuisance of waste plastic hazardous to ecosystem. Neeraj Mishra, Sunil Pandey, Bhushan Patil, Mukeshchand Thukur, Ashmi Mewada, Madhuri Sharon, and Maheshwar Sharon Copyright © 2014 Neeraj Mishra et al. All rights reserved. Potential of NMR Spectroscopy in the Characterization of Nonconventional Oils Thu, 02 Jan 2014 09:23:44 +0000 NMR spectroscopy was applied for the characterization of two biomass based pyrolysis oil samples. The samples were extracted in various solvents and the extracts were investigated by both 1H and 13C NMR spectroscopy. Subsequent evaluation of the integrated analytical data revealed chemical information regarding semiquantitative estimation of various functional groups. This information could not have been obtained readily from the individual spectroscopic techniques. Semiquantitative estimation of the various functional groups allowed a comparison of the extraction efficiency of these groups in various solvents. The method is based on the premise that although the number of individual molecular species in pyrolysis oil liquid is large, most of these species are composed of a limited number of functional groups. The methodology provided information on the concentration of chemical functionalities that are potentially useful for synthetic modifications and may help to guide the use of pyrolysis oil as a chemical feedstock. The approach described is expected to be generally applicable to complex mixture of hydrocarbon oils such as bio-oils, oil sands bitumen, and coal pyrolysis oils. Abdul Majid and Indu Pihillagawa Copyright © 2014 Abdul Majid and Indu Pihillagawa. All rights reserved. Effect of Coexistent Hydrogen on the Selective Production of Ethane by Dehydrogenative Methane Coupling through Dielectric-Barrier Discharge under Ordinary Pressure at an Ambient Temperature Wed, 01 Jan 2014 21:07:45 +0000 The effect of coexistence of hydrogen on the product selectivity to ethane from methane by dielectric-barrier discharge (DBD) reactor was examined experimentally under ordinary pressure without use of catalyst and external heating. By the dilution of methane with hydrogen, both the increase of methane conversion and the decrease of alkene production were observed, improving the selectivities to ethane by ca. 70%. Katsuya Konno, Kaoru Onoe, Yasuyuki Takiguchi, and Tatsuaki Yamaguchi Copyright © 2014 Katsuya Konno et al. All rights reserved.