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  • Kinetic modeling of the direct synthesis of dimethyl ether over a CuO‑ZnO‑MnO/SAPO‑18 catalyst and assessment of the CO2 conversion
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-10-04
    Ainara Ateka, Javier Ereña, Javier Bilbao, Andrés T. Aguayo

    A kinetic model has been established for the direct synthesis of dimethyl ether (DME) from syngas and CO2 feeds. The kinetic parameters have been determined fitting the experimental results obtained using a CuO‑ZnO‑MnO/SAPO‑18 (CZMn/S) bifunctional catalyst in a fixed‑bed isothermal reactor, under a wide range of operating conditions: 250–350 °C; 10–40 bar; CO2/CO molar ratio in the feed, between 0 and 1; H2/COX molar ratio in the feed, 3/1 and 4/1; space time, from 1.25 gcath(molC)−1, up to 20 gcath(molC)−1; time on stream, up to 30 h. The model considers the kinetic equations of the individual reactions of methanol synthesis from CO and CO2, the dehydration of methanol to DME, the water gas shift reaction (WGS) and the formation of paraffins, along with the deactivation kinetics. The attenuation of the reaction rates of methanol and paraffins synthesis has been considered by the competitive adsorption of CO2 and H2O in the metallic sites with respect to the adsorption of CO (more reactive than CO2 in the synthesis of methanol). The deactivation by coke has been quantified by a kinetic equation dependent on the concentrations of methanol and DME, and the attenuation of the deactivation by the competitive adsorption of CO2 and H2O has also been considered in this equation. The kinetic model allows predicting satisfactorily the evolution with time on stream of the concentration of the components in the reaction medium (methanol, DME, unreacted CO and CO2, and paraffins formed as by‑products). In addition, the model has been used to simulate the reactor, determining the effect of the reaction conditions on the conversion of CO2. This conversion, in contrast to the yield of DME, increases with increasing CO2 concentration in the reactor feed.

    更新日期:2018-10-06
  • Production and utilization of fuel pellets from biomass: A review
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-10-04
    Priyabrata Pradhan, Sanjay M. Mahajani, Amit Arora
    更新日期:2018-10-06
  • Effects of HZSM-5 on volatile products obtained from the fast pyrolysis of lignin and model compounds
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-10-04
    Huamei Yang, Koyo Norinaga, Ji Li, Wenyou Zhu, Haijun Wang

    This study aimed to experimentally investigate the effect of HZSM-5 on the distribution of volatile products, especially carbon monoxide (CO), C1–C5 hydrocarbons and aromatic hydrocarbons (AHs) during catalytic pyrolysis of lignin and lignin model compounds. Catechol was pyrolyzed using a two-stage tubular reactor (TS-TR) connected to a gas chromatography system over HZSM-5 at 550–950 °C. Forty-three products, including four inorganic gases, twenty C1–C5 hydrocarbons, and nine AHs were quantified using three GC-columns. Results indicated that HZSM-5 accelerated the catechol conversion with a large amount of CO and AHs produced. C1–C5 hydrocarbons were formed during non-catalytic pyrolysis of model compounds, and consumed quickly during HZSM-5 catalytic pyrolysis of catechol. Catalytic pyrolysis of phenol, guaiacol and syringol was carried out at 650 °C in the TS-TR over HZSM-5. HZSM-5 obviously promoted the conversion of lignin model compounds, and largely increased the yield of volatile products especially CO and AHs. Three lignin samples were also catalytically pyrolyzed over HZSM-5 in the TS-TR at 650 °C. HZSM-5 increased the yield of C2-C3 hydrocarbons and AHs, and reduced the yield of oxygenated compounds. HZSM-5 could promote the formation of AHs (lower than 10 wt%) during lignin pyrolysis, but not as obviously as during model compounds pyrolysis (higher than 19 wt%). High yields of char and tar would account for the low catalytic efficiency of HZSM-5 during lignin pyrolysis.

    更新日期:2018-10-04
  • Direct conversion of biomass-derived carbohydrates to 5-hydroxymethylfurfural using an efficient and inexpensive manganese phosphate catalyst
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-10-03
    Siquan Xu, Donghui Pan, Wenqi Li, Pengxin Shen, Yuanfeng Wu, Xianghai Song, Yanli Zhu, Ningning Xu, Lijing Gao, Guomin Xiao

    Achieving high yields of 5-hydroxymethylfurfural (HMF) from carbohydrates remains a challenge today. With the aim of developing an efficient and inexpensive catalyst for the production of HMF, manganese phosphate (MnPO4) was used as the sole catalyst for the catalytic conversion of biomass-derived carbohydrates into HMF in the H2O/tetrahydrofuran (THF) biphasic reaction system. The effects of various factors, including reaction temperature, reaction time, system, and catalyst dosage on the conversion of carbohydrates to HMF were explored. An impressing HMF yield of 59% was achieved with glucose as a feedstock at 160 °C for 90 min. Meanwhile, up to 44% of HMF was also obtained with microcrystalline cellulose as a feedstock at 170 °C for 120 min. In addition, MnPO4 catalyst also displayed outstanding catalytic activities for the conversion of other biomass-derived carbohydrates including monosaccharides and disaccharides. Combined with the dissolution characteristics of the MnPO4, a possible catalytic mechanism for the conversion of carbohydrates into HMF catalyzed by MnPO4 was proposed. The catalytic approach proposed in this paper exhibited a promising potential for HMF production via optimizing the catalytic process.

    更新日期:2018-10-04
  • Methane conversion using carbon dioxide as an oxidizing agent: A review
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-10-03
    Tomohiro Yabe, Yasushi Sekine
    更新日期:2018-10-04
  • Waste materials as potential catalysts for biodiesel production: Current state and future scope
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-10-03
    Akshey Marwaha, Pali Rosha, Saroj Kumar Mohapatra, Sunil Kumar Mahla, Amit Dhir

    Recent studies on the exploration of eco-friendly approach by utilizing large-scale waste materials as potential catalyst in biodiesel production have attracted much attention. The development of heterogeneous catalysts especially from calcium has gained much awareness due to the large availability of calcium-rich waste materials and their corresponding high catalytic activity in the transesterification of oil. Most of the waste materials employed as heterogeneous catalysts have an abundance of natural Ca content and they have high catalyst activity and selectivity despite being environment-friendly and cost-effective. Heterogeneous catalysts with high activity can be produced from Ca based waste materials when calcined at high temperatures. This review gives a brief overview of the developments of various Ca based catalysts derived from waste materials as an efficient catalyst for biodiesel production with significant yield. Industrial wastes (red mud, slag, ash) and biological catalysts (chicken eggshells, mollusk shells, animal bones) possess enormous potential towards developing an economical catalyst and subsequently, low-cost biodiesel generation. However, future challenges await a better utilization of useless wastes into a useful resource to satisfy human needs.

    更新日期:2018-10-04
  • Near-azeotropic volatility behavior of hydrous and anhydrous ethanol gasoline mixtures and impact on droplet evaporation dynamics
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-10-02
    Bahareh Abdollahipoor, Saeid Aghahossein Shirazi, Kenneth F. Reardon, Bret C. Windom

    After fermentation, the concentration of bioethanol is only 8–12 wt%. To produce anhydrous ethanol fuel, a significant amount of energy is required for separation and dehydration. Once the azeotrope composition is reached, distillation can no longer be exploited for purification and more expensive methods must be used. Replacing anhydrous ethanol fuel with hydrous ethanol (at the azeotrope composition) can result in significant energy and cost savings during production. The goal of this study was to characterize the volatility behavior and the droplet evaporation dynamics of hydrous and anhydrous ethanol gasoline blends. Three hydrous ethanol-gasoline blends (10, 15, and 30 vol%) in which the hydrous ethanol was composed of the azeotropic proportions of ethanol and water, and three anhydrous ethanol gasoline blends (10, 15, and 30 vol%) were prepared and analyzed with the advanced distillation curve method. Distillation curves were obtained for all test fuels and distillate samples were taken during the distillation process. A droplet evaporation model validated with the distillation data was exploited to understand how the non-ideal volatility behavior of these blends, the high heat of vaporization of water, and altered fluid properties can affect the transient droplet evaporation phenomena and thus the fuel's potential to effectively mix with air in direct injection internal combustion engines. Minor differences in the distillation curves and vapor-liquid equilibrium between the hydrous and anhydrous fuels were measured. Droplet modeling results showed that the higher heat of vaporization and viscosity of water relative to ethanol can lead to significant differences in the net droplet evaporation time between the two types of blends, especially at the higher blending ratios evaluated. These results suggest that the presence of water in ethanol-gasoline blends may extend droplet lifetimes and increase the susceptibility of the fuel to form particulate matter emissions. This is the first study to use distillation methods to gain a better understanding of evaporation behavior and the role of water's non-linear vapor-liquid equilibrium on droplet evaporation dynamics.

    更新日期:2018-10-02
  • Co-processing of crude and hydrotreated pyrolysis liquids and VGO in a pilot scale FCC riser setup
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-29
    Chenxi Wang, Robbie Venderbosch, Yunming Fang
    更新日期:2018-10-01
  • Relationship of thermal degradation behavior and chemical structure of lignin isolated from palm kernel shell under different process severities
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-28
    Zhongqing Ma, Junhao Wang, Hanzhi Zhou, Yu Zhang, Youyou Yang, Xiaohuan Liu, Jiewang Ye, Dengyu Chen, Shurong Wang
    更新日期:2018-09-29
  • Investigation of fluctuation behavior in viscosity of coal slags used in entrained-flow gasifiers
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-27
    Yashi Ma, Guixuan Wu, Qinghua Guo, Xia Liu, Yan Gong, Guangsuo Yu

    Entrained-flow gasification has attracted extensive attention because of its clean and efficient utilization of coal as well as flexible application in industry for power generation and chemical production. Numerous theoretical and experimental investigations on slag flow in entrained-flow gasifiers have been performed to ensure a smooth operation, but an unscheduled shutdown due to slag tap blockage remains an ongoing challenge. A fluctuation phenomenon of slag viscosity gives a rise in the risk of slag tap blockage. In this work, three Chinese coal slags with low silicon content and high iron content were used to investigate the viscosity fluctuation phenomenon. It was found that the crystalline phases and suspended bubbles can cause the fluctuation phenomenon. The fluctuation degree is related to the volume fraction of crystalline phases and the crystallization rate. In the search for the mechanism of the viscosity fluctuation, an in-situ observation using a high temperature stage microscope system (HTSM) in combination with XRD and SEM analyses was carried out. In addition, the viscosity of investigated slags with the suppression of solid phases as well as the phase distribution at high temperatures was calculated. Based on a comprehensive analysis of the results, a possible mechanism has been proposed that the viscosity fluctuation is attributed to an instant local change in the macrostructure such as the deformation of suspended bubbles, the change of the orientation of acicular crystals and the interaction of the acicular crystals and suspended bubbles.

    更新日期:2018-09-28
  • Advancement in technologies for the depolymerization of lignin
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-25
    Ashutosh Agarwal, Masud Rana, Jeong-Hun Park

    Lignin is one of the largest sources of naturally occurring aromatic building blocks that possess immense potential to be employed as starting material for the production of value-added chemicals involving biofuels. Despite various challenges associated with lignin valorization, several strategies have emerged that could deliver value-added products in good yields. The present contribution aims to critically review recent advancements in biological, thermochemical and electrochemical strategies for lignin depolymerization mainly focusing on enzymatic, acid/base/metal-catalyzed, and microwave-assisted degradation approaches. All lignin degradation strategies result in the production of an arsenal of several monomeric, oligomeric and polymeric compounds, with no single molecule being produced in significant amount. For large-scale production of biofuels and other value-added chemicals via lignin depolymerization, the combination of two or more technologies with low cost and recyclable catalysts operating at mild reaction conditions needs to be explored.

    更新日期:2018-09-26
  • A comprehensive review on laminar spherically premixed flame propagation of syngas
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-25
    Yongliang Xie, Xujiang Wang, Haiquan Bi, Yanping Yuan, Jinhua Wang, Zuohua Huang, Bo Lei

    Integrated Gasification Combined Cycle is a technology which has been studied widely as a future clean energy system. As one important portion of it, syngas premixed combustion is crucial due to its immediate impact on the efficiency and emission. However, its control is challenging since turbulent combustion in the chamber is extremely complex due to the composition variability and structural complexity of the combustion devices. Deep study on the laminar premixed combustion of syngas is of great importance for revealing the real complex turbulent combustion process. In the present paper, recent progress in fundamental research on laminar spherically premixed flame propagations of syngas, including laminar flame speed, Markstein length, flame stretch, cellular flame structure and self-acceleration are presented. Detailed summaries and discussions for different stages of the flame propagation are given. In particular, laminar flame speed and wrinkled flame front due to intrinsic flame instability are emphasized. Furthermore, future prospects on laminar spherically premixed flame propagation of syngas mixtures are discussed.

    更新日期:2018-09-25
  • Pore structure evaluation of cementing composites blended with coal by-products: Calcined coal gangue and coal fly ash
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-24
    Jin Yang, Ying Su, Xingyang He, Hongbo Tan, Youzhi Jiang, Linghao Zeng, Bohumír Strnadel

    Coal gangue (CG) and coal fly ash (FA) are the main coal by-product wastes. This paper focuses on the pore structure evaluation of CG and FA blended cementing composites with various replacement levels from 3 days up to 180 days. Results indicate that negative effect of coal by-products on the compressive strength and average pore size can be reduced to a negligible level at late ages. Similar average pore size (~10 nm) and critical width (10–20 nm) are found for CG and FA composites after 90 days. Moreover, the blended composites have significantly higher gel pore fraction, and the higher the dosage the larger the gel pore fraction. Multi-fractal feature is observed with the fact that scale of micro-fractal region is found always broader than the macro-fractal region and the micro-Ds is found always larger than the macro-Ds. Both the micro- and macro-Ds of blended composites are systematically larger than the plain pastes.

    更新日期:2018-09-25
  • 更新日期:2018-09-25
  • Power-to-Gas through thermal integration of high-temperature steam electrolysis and carbon dioxide methanation - Experimental results
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-22
    Manuel Gruber, Petra Weinbrecht, Linus Biffar, Stefan Harth, Dimosthenis Trimis, Jörg Brabandt, Oliver Posdziech, Robert Blumentritt

    This article presents the experimental results of a novel Power-to-Gas (PtG) concept combining a pressurized high-temperature steam electrolysis (SOEC) and a CO2-methanation module in stand-alone and thermally integrated operation. For the electrolyser, steam conversion and energy demands at pressures up to 15 bar were examined. In terms of the methanation module, cooling performance, steam production and product gas quality were of main interest. Additionally, temperature profiles inside the fixed beds were gathered by a multipoint thermocouple at pressures up to 30 bar and load modulations from 20 to 100%. With less than 2 vol% H2 and over 97 vol% CH4 in the finally produced synthetic natural gas (SNG), it can be directly injected into the existing German natural gas grid without further gas cleaning and without capacity limitations. The achieved overall PtG efficiency of 76% is significantly higher than state of the art plants and has the potential to reach 80% in industrial scale.

    更新日期:2018-09-25
  • Impacts of amount of chemical agent and addition of steam for activation of petroleum coke with KOH or NaOH
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-22
    Jingfeng Wu, Vicente Montes, Luis D. Virla, Josephine M. Hill
    更新日期:2018-09-25
  • Influence of mesostructured alumina on the morphology of the active phase in NiWS/Al2O3 catalysts and their activity in hydrotreating of SRGO and VGO
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-21
    Pavel Minaev, Maria Nikulshina, Alexander Mozhaev, Konstantin Maslakov, Roman Boldushevskii, Pavel Nikulshin
    更新日期:2018-09-21
  • Excellent low temperature NH3-SCR activity over MnaCe0.3TiOx (a = 0.1–0.3) oxides: Influence of Mn addition
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-20
    Xuesong Leng, Zhiping Zhang, Yushi Li, Tianrui Zhang, Shibo Ma, Fulong Yuan, Xiaoyu Niu, Yujun Zhu
    更新日期:2018-09-20
  • Effect of CaO/Fe2O3 on fusion behaviors of coal ash at high temperatures
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-19
    Wen-Ju Shi, Ling-Xue Kong, Jin Bai, Jiang Xu, Wei-Cheng Li, Zong-Qing Bai, Wen Li

    The ash fusibility, usually investigated and evaluated by the ash chemical composition, is widely used for guiding the coal utilization in boiler and gasifier. The ratio of basic and acidic oxides (B/A) in coal ash is the most important parameter for ash fusibility evaluation. While the coal ash has the identical B/A ratio, SiO2/Al2O3 and CaO/Fe2O3 ratio also show significant influence on the ash fusibility. However, the researches on CaO/Fe2O3 on ash fusibility are rare. In order to quantify the influence of CaO/Fe2O3 on the ash fusibility, thermal mechanical analyzer (TMA) is applied to investigate the ash fusion behavior of coal ash with various CaO/Fe2O3 ratios. XRD, FactSage and DSC are combined to explore the ash fusion characteristics and mechanisms. The results showed that AFTs increased with the increasing of CaO/Fe2O3 ratio, which was attributed to variation of Fe2O3 content and iron valence. However, the ash with low CaO/Fe2O3 ratio trended to form mullite, increasing AFTs. Hence, the optimal CaO/Fe2O3 ratio for fluxing effect existed to balance the mineral component and iron valence. The different shrinkage curves were attributed to the different fusion events and different mechanism. The fusion process of ash (CaO/Fe2O3 = 0.25) exhibited as the behavior of a pure substance, which has the narrow fusion range. And the fusion range was dominated by the low temperature eutectics including spinel, quartz, corundum, and anorthite, which were beneficial for preventing ash sintering. Meanwhile, the fusion process of ash sample (CaO/Fe2O3 = 4) occurred step by step, and it had a wide fusion range. The low-melting point minerals such as wollastonite, clinopyroxene, calcium silicate induced and manipulated the fusion process. These ash samples with the wide fusion range were favored for slagging process. Besides, the shrinkage rate of ash was mainly determined by the slag formation rate when viscosity was low, but it was dependent on slag formation rate as well as viscosity for the high viscosity slag. Two correlated relations between shrinkage rate and ratio of liquid phase formation rate and viscosity for ash with CaO/Fe2O3 < 1 and CaO/Fe2O3 ≥ 1 were established to prevent ash sintering at high temperatures.

    更新日期:2018-09-20
  • Kinetic compensation effects in the chemical reaction-controlled regime and mass transfer-controlled regime during the gasification of biochar in O2
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-20
    Muhammad Asif Akhtar, Shu Zhang, Xin Shao, Huu Dang, Yurong Liu, Tingting Li, Lei Zhang, Chun-Zhu Li

    This study aims to investigate the kinetic compensation effects during the char-O2 reaction in a fluidised-bed reactor for two particle sizes of 0.80–1.0 mm and 2.0–3.35 mm. The rate of char-O2 reaction was determined by analysing the gasification product gas composition in a quadrupole mass spectrometer. The char-O2 reaction exhibited different kinetic compensation effects between apparent activation energy and apparent pre-exponential factor in the kinetics-controlled, diffusion-controlled and mixed regimes for both particle sizes. The same reaction mechanism is followed during the char-O2 reaction in the kinetic regime at same or at different pyrolysis temperatures as revealed by the kinetic compensation effects. In the mixed regime, higher diffusion limitations increased the m and c values in the kinetic compensation effect lnAapp = mEapp + c for any given particle size. Due to higher rates of reaction at higher char conversions, the char-O2 reaction switched from kinetics-controlled to mixed regimes, resulting in higher slopes ‘m’ and y-intercepts ‘c’ in the kinetic compensation effects. The absence of isokinetic temperature at higher conversions indicates that char properties changed significantly at higher conversions compared with those at lower conversions.

    更新日期:2018-09-20
  • Influence of oxidizer injection angle on the entrained flow gasification of torrefied wood powder
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-18
    Yngve Ögren, Marcus Gullberg, Jonas Wennebro, Alexey Sepman, Pál Tóth, Henrik Wiinikka

    In the present work, 5 different axisymmetric burners with different directions of the oxidizer inlets were experimentally tested during oxygen blown gasification of torrefied wood powder. The burners were evaluated under two different O2/fuel ratios at a thermal power of 135 kWth, based on the heating value of torrefied wood powder. The evaluation was based on both conventional methods such as gas chromatography measurements and thermocouples and in-situ measurements using Tunable Diode Laser Absorption Spectroscopy. It was shown that changes in the near burner region influence the process efficiency significantly. Changing the injection angle of the oxidizer stream to form a converging oxidizer jet increased process efficiency by 20%. Besides increased process efficiency, it was shown that improvements in burner design also influence carbon conversion and hydrocarbon production. The burner with the best performance also produced less CH4 and achieved the highest carbon conversion. The effect of generating swirl via rotating the oxidizer jet axes was also investigated. Swirl broadened or removed the impingement area between the fuel and oxidizer jets, however resulting in differences in performance within the measurement uncertainty.

    更新日期:2018-09-19
  • MOFs-derived N-doped carbon matrix superacid-catalyzed hydrocracking of a residue from thermal dissolution of Hefeng subbituminous coal
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-17
    Zheng Yang, Xian-Yong Wei, Zhi-Xin Li, Min Zhang, Zhi-Min Zong, Zhe-Hao Wei, Yan Li
    更新日期:2018-09-19
  • Co-pyrolysis of lignin and low rank coal for the production of aromatic oils
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-11
    Enkhsaruul Byambajav, Hooman Paysepar, Laleh Nazari, Chunbao (Charles) Xu

    The co-pyrolysis of hydrolysis lignin and low rank coal was studied in a drop-tube fixed bed reactor. Baganuur (BN) coal blending into hydrolysis lignin with mass ratio of 50:50 decreased the yields of oil and gas significantly, and then increased the yield of char compared to their predicted values after the co-pyrolysis at 450 °C. This toxic effect was explained by the easier coupling reaction of BN coal derived poly-aromatic radicals with hydrolysis lignin (HL)-derived aromatic compounds to form solid product - char. However, when the amount of BN coal in the blend decreased from 50% to 30%, the toxic effect decreased, and experimental yields of char, oil and gas approached to their predicted values. In case of HL-AC (50:50) blend, a synergistic effect was observed during the co-pyrolysis of hydrolysis lignin and Aduunchuluun (AC) coal. The oil yield slightly increased, and the yields of gas and char decreased compared to their predicted values after the co-pyrolysis at 450 °C. Amount of aromatic hydrocarbons in acetone soluble of the oil was close to its predicted value, and several kinds of aliphatic alcohols, aldehydes and ketones were detected in toluene soluble of the oil product, even though there were no such compounds existed in the toluene soluble from the pyrolysis of single feed-AC coal. It was supposed that additional hydrogen was produced by the secondary water-gas shift reaction of CO gas evolved from AC coal with large amount of inherent alkali and alkali earth metals during the HL-AC co-pyrolysis. It was also supported by the larger H/C ratios of oil and char compared to their predicted values after the co-pyrolysis of HL-AC blend.

    更新日期:2018-09-12
  • Carbon clusters decorated hard carbon nanofibers as high-rate anode material for lithium-ion batteries
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-11
    Chang Liu, Nan Xiao, Yuwei Wang, Hongqiang Li, Gang Wang, Qiang Dong, Jinpeng Bai, Jian Xiao, Jieshan Qiu
    更新日期:2018-09-12
  • Hydroconversion of methyl laurate over silica-supported Ni–Mo catalysts with different Ni sizes
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-10
    Hiroyuki Imai, Miku Abe, Kazusa Terasaka, Takuya Suzuki, Xiaohong Li, Toshiyuki Yokoi
    更新日期:2018-09-11
  • Breakthrough studies of Co3O4 supported activated carbon monolith for simultaneous SO2/NOx removal from flue gas
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-09-10
    Kiman Silas, Wan Azlina Wan Ab Karim Ghani, Thomas Shean Yaw Choong, Umer Rashid
    更新日期:2018-09-11
  • Comparative investigation of a co-firing scheme in a lignite-fired boiler at very low thermal-load operation using either pre-dried lignite or biomass as supporting fuel
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-08-29
    Panagiotis Drosatos, Nikolaos Nikolopoulos, Emmanuil Karampinis, Panagiotis Grammelis, Emmanuil Kakaras

    This work presents an investigation of an indirect firing scheme using biomass (cardoon) as supporting fuel for a pulverized-lignite boiler during its operation at a thermal load of 35%, lower than the current minimum one. Results are compared with an alternative indirect firing scheme which employs pre-dried lignite (PDL) as supporting fuel. The numerical investigation of the boiler has been conducted using the commercial software ANSYS Fluent® v15.0, supported by in-house built functions for the combustion rate of the fuels and the drag force exerted on biomass particles. The simulation and the comparison of the combustion of two different fuel blends in a co-firing strategy is important in order to evaluate technically the available possibilities and select among them the optimal firing concept (number and position of the operating injection ports) and the ideal fuel blend for the operation of the unit at lower than technical minimum thermal loads, in order to attain reduction of emissions and improvement of the boiler flexibility. Due to the implementation of a two-stage over-fire air (OFA) system and the consideration of sub-stoichiometric conditions exhibited at the nominal load, this work also takes into consideration the modeling of the boiler convective section, following the porous media analysis provided by the available Macro Heat Exchanger Model, ANSYS Fluent®. The validation of the applied models has been performed in previous works of the same group of authors, while the combustion results regarding crucial combustion parameters have been compared against corresponding values derived by a suitably-developed thermodynamic model. The agreement between these two models is good, since the maximum percentage deviation is calculated to be in the range of approximately 10%. Based on the numerical results, it can be concluded, that the utilization of both types of supporting fuel can ensure the stable operation of the boiler at thermal loads, lower than the technical minimum of the unit, promoting its flexibility. Between the two different supporting fuels, it is observed, that biomass ensures higher combustion efficiency compared to pre-dried lignite. However, it is also indicated, that the reduction of NOx emissions and the intensity of the induced thermal loading on the membrane walls with the utilization of biomass is more dependent on the firing strategy compared to lignite, proving the key role that this parameter plays to the operation of a boiler using this specific fuel blend.

    更新日期:2018-08-29
  • Biomass ash induced agglomeration in fluidized bed. Part 2: Effect of potassium salts in different gas composition
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-08-24
    Teng Ma, Chuigang Fan, Lifang Hao, Songgeng Li, Peter Arendt Jensen, Wenli Song, Weigang Lin, Kim Dam-Johansen

    Agglomeration is one of the main challenges for combustion and gasification of biomass in fluidized beds. Bed agglomeration is related to K species present in biomass. Understanding the role of different types of K species on formation of agglomerates at different conditions can reveal the mechanisms of biomass ash induced agglomeration. Extensive experiments are conducted in a laboratory scale fluidized bed reactor, using mixtures of quartz sand and K species, including KCl, K2SO4 and K2CO3, to study the agglomeration mechanisms. The effects of gas composition, including air, H2– and H2O– containing gas are investigated. The morphology and elemental analyses of the agglomerate samples are examined by SEM/EDS analysis. Thermodynamic equilibrium calculations are performed for verifying the proposed mechanisms. The results show that the role of various forms of potassium salts on agglomeration in fluidized beds is different. Gas composition also has strong impact on the agglomeration tendency. In the air and H2-containing gas, defluidization of KCl in a sand bed is caused by the melt of KCl. However, KCl reacts with SiO2 to form K-silicates in the H2O-containing gas, which results in a lower defluidization temperature. No defluidization is observed for K2SO4 in the presence of oxygen or water. However, K2SO4 decomposes and reacts with SiO2 to form K-silicates, causing defluidization at 850 °C in the H2-containing gas. In the air, H2– or H2O-containing gas, K2CO3 would react with SiO2 to form potassium silicates and KOH may be additionally formed in the H2– and H2O-containing gas. The possible mechanisms of agglomeration of various potassium salts at different conditions are discussed.

    更新日期:2018-08-26
  • A simple model for comparative evaluation of different oxygen carriers and solid fuels in iG-CLC processes
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-08-13
    A. Abad, T. Mendiara, L.F. de Diego, F. García-Labiano, P. Gayán, J. Adánez

    A simple model based on oxygen carrier kinetics has been developed for the in situ Gasification Chemical Looping Combustion (iG-CLC) process. Once the kinetic parameters for different oxygen carriers and solid fuels are known, the model allows easy and fast comparison of different oxygen carrier-solid fuel pairs, which is the main purpose of the model here presented. The comparison is based on the estimation of the CO2 capture efficiency value (ηCC) and the total oxygen demand (ΩT) as evaluating parameters. To show the proposed procedure for the comparison, two Fe-based oxygen carriers (ilmenite and Tierga ore), and five different types of solid fuels: anthracite (Yangquan), sub-bituminous (Tremedal), two bituminous coals (Cerrejón and Taldinsky) and one biomass (olive tree pruning) have been considered. The comparison of the calculated CO2 capture efficiency and total oxygen demand must be done including the effect of operating conditions such as temperature and solids circulation rate. A set of optimized operating conditions are given as a reference for future evaluations of different oxygen carrier-solid fuel pairs. This method is thought as a useful tool for a preliminary evaluation of new oxygen carriers for iG-CLC with different solid fuels.

    更新日期:2018-08-26
  • Cellulose-lignin interactions during catalytic pyrolysis with different zeolite catalysts
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-08-08
    Yan Wu, Shiliang Wu, Huiyan Zhang, Rui Xiao

    Interactions between cellulose and lignin under catalytic pyrolysis condition were investigated to identify the impact of zeolite catalysts on products distributions. Thermogravimetric Analysis (TGA) and Pyrolysis-Gas Chromatography/Mass Spectroscopy (Py–GC/MS) were used to investigate cellulose-lignin interactions. The mixing ratio of cellulose and lignin was 1:1 and the pyrolysis temperature was 600 °C. The results showed that interactions did exist under both non-catalytic and catalytic pyrolysis condition. Decomposition of cellulose during catalytic co-pyrolysis was inhibited. For some research-focused products from cellulose, the interactions between cellulose and lignin under catalytic process all inhibited the formation of levoglucosan, but interactions under H-beta catalyst promoted the formation of furfural. Meanwhile, for lignin-derived products, the catalytic interactions all inhibited the formation of phenol and guaiacol with all the tested catalysts. This is opposite to the results from non-catalytic condition, where the cellulose-lignin interactions promoted the formation of phenol and guaiacol. A statistic method-correlation coefficient R was introduced to evaluate the interaction strength under different catalysts pyrolysis; strongest catalytic interaction was found when H-beta was used, followed by HZSM-5 and SAPO-34.

    更新日期:2018-08-26
  • Catalytic hydrogenation of soybean oil-derived fatty acid methyl esters over Pd supported on Zr-SBA-15 with various Zr loading levels for enhanced oxidative stability
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-08-07
    Chachchaya Thunyaratchatanon, Apanee Luengnaruemitchai, Nuwong Chollacoop, Shih-Yuan Chen, Yuji Yoshimura
    更新日期:2018-08-26
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  • Catalyst deactivation in the direct synthesis of dimethyl ether from syngas over CuO/ZnO/Al2O3 and γ-Al2O3 mechanical mixtures
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-29
    Raquel Peláez, Ewan Bryce, Pablo Marín, Salvador Ordóñez

    Direct synthesis of dimethyl ether from syngas over mixed catalysts constitutes a novel route aimed to replace the traditional two-step process. Many previous studies about this one-step process showed that catalyst deactivation is unavoidable. The present study wants to characterize the deactivation of CuO/ZnO/Al2O3 and γ-Al2O3 mechanical mixtures, and develop a deactivation model for predicting catalyst performance in presence of deactivation. It was demonstrated that water adsorbs over the γ-Al2O3 surface, blocking its active sites and causing a sharp conversion drop (mainly observed during the first hours on stream). This effect was reversible and could be avoided by increasing temperature (270 °C or above). The other deactivation mechanism was the deposition of carbonaceous species over the catalyst surface. A deactivation model was proposed and fitted to the experimental data.

    更新日期:2018-08-26
  • Gas and soot formed in the dimethoxymethane pyrolysis. Soot characterization
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-29
    Katiuska Alexandrino, Ángela Millera, Rafael Bilbao, María U. Alzueta

    The many simultaneous processes occurring within in a diesel engine make difficult a thorough understanding of the mechanisms responsible for reduction of soot and/or NOX when an oxygenated compound is added to diesel fuel. Thus, in order to explore the use of oxygenated compounds as biofuels/additives, it is interesting to study their conversion under well-controlled laboratory conditions, together with kinetic studies that help to interpret and understand the reaction schemes that occur during such processes. The aim of this work has been to contribute to the knowledge of the dimethoxymethane (DMM) pyrolysis, one of the oxygenated compounds proposed in literature as alternative fuel. In this way, the influence of pyrolysis temperature (1075–1475 K) and inlet fuel concentration (33,333 and 50,000 ppm DMM) on the sooting propensity of DMM, soot reactivity and its properties is analyzed. Therefore, this work includes pyrolysis experiments under different experimental conditions, focusing on the gas-phase analysis and the soot formation, together with a gas-phase model. Additionally, the interaction of soot with O2 and with NO has been studied, and since soot properties are important on the oxidation rate, selected soot samples have been characterized by different instrumental techniques (elemental analysis, physical adsorption with N2, Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), and Raman spectroscopy).

    更新日期:2018-08-26
  • Investigation of the deposition characteristics of ammonium bisulfate and fly ash blend using an on-line digital image technique: Effect of deposition surface temperature
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-27
    Hao Zhou, Jiakai Zhang, Kun Zhang

    The problem of ammonium bisulfate (ABS) deposition blocking and corroding air preheaters and economizers in boilers became severe, as the selective catalyst reduction (SCR) system was widely used in the coal-fired boilers to meet the stringent nitrogen oxide (NOX) discharge standard. In this study, an online digital image technique was applied to investigate the growth of the deposition of fly ash and ABS blend in a drop tube furnace (DTF). The deposition was measured on a temperature controlled deposition probe. The results of the image technique showed that the surface temperature of the deposition probe had a negative effect on stable thicknesses of the blend depositions and the stable thicknesses for cases 1 (553 K), 2 (513 K), and 3 (473 K) are 4.78, 5.26, and 7.64 mm, respectively. Meanwhile, the relative variation of the heat flux QR for Cases 1, 2, and 3 are 17.8%, 33.8%, and 40.2%. The deposition in the lower deposition surface temperature has a greater effect on the heat transfer efficiency. In order to understand the deposition formation of fly ash and ABS blend, the X-ray diffraction (XRD), X-ray fluorescence (XRF), and the scanning electron microscopy (SEM) analysis were undertaken of the blend deposition. The results indicated that the content of ABS in the bottom part deposition increased as the probe surface temperature decreases, and this would result in more agglomerates in the deposition according to the observations of the SEM and the growth behavior of the deposition was influenced. Meanwhile, the results show that the deposition characteristics of ABS and fly ash blend is strongly influenced by the distribution and the condensation behavior of ABS. This work makes a contribution to a deeper understanding of deposition characteristics of ammonium bisulfate and fly ash blend, which is important for boilers to control the blend deposition in air preheaters and economizers.

    更新日期:2018-08-26
  • Antioxidants as additives in wood pellets as a mean to reduce off-gassing and risk for self-heating during storage
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-27
    Mehrdad Arshadi, Tobias Tengel, Calle Nilsson

    Spontaneous self-heating and off-gassing of wood pellets during storage is well-recognized problem. The reason for the phenomena is be autoxidation of fatty/resin acids in the pellets material. Two antioxidants, TBHQ (tert-Butylhydroquinone) and PG (propyl gallate), have been used as additives during pellets production in order to investigate how effective these antioxidants are in blocking autoxidation. Off-gassing of volatile aldehydes, CO and CO2 from wood-pellets and depletion of O2 during storage at room temperature in two different scales of closed storage systems were investigated and antioxidant fortified pellet batches and a reference batch without additive were compared. The results show that TBHQ is an efficient antioxidant at a low concentration (0.5%) in blocking autoxidation of fatty/resin acids in wood pellets. The CO emissions are reduced between 72 and 90% depending on the pellets temperature. Some of the fatty acids are almost intact in the samples with TBHQ compared to reference sample; showing that TBHQ blocking degradation by autoxidation of those fatty acids. For PG, autoxidation has not been blocked. The total amount of emitted aldehydes are 77% less than in pellets made with antioxidants as compared to the reference pellets, showing that TBHQ is acting as inhibitor in the autoxidation processes.

    更新日期:2018-08-26
  • 更新日期:2018-08-26
  • 更新日期:2018-08-26
  • Solvent-free catalytic deoxygenation of oleic acid via nano-Ni/HZSM-5: Effect of reaction medium and coke characterization
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-24
    Shiyou Xing, Pengmei Lv, Che Zhao, Ming Li, Lingmei Yang, Zhongming Wang, Yong Chen, Shijun Liu

    Non-H2 and solvent-free catalytic conversion of waste lipids to liquid hydrocarbons is of great interest because of the associated low-cost, full-safety, and easy-operability. In this work, a solvent-free catalytic process for deoxygenating oleic acid was performed in H2 and non-H2 (N2, CH4, and CO2) media over nano-Ni/HZSM-5. 8-Heptadecene, a primary product obtained at 320 °C in four media, was derived from the straightforward decarboxylation of oleic acid. In non-H2 medium at 360 °C, the formation of C8–C15 alkanes was enhanced, with yields of ca. 65.05 mol%, 70.71 mol%, and 73.09 mol% for N2, CH4, and CO2, respectively. A low yield of 49.67 mol% C8–C15 alkanes in H2 medium suggested that the H2 medium reduced catalytic cracking. This was due to the preferential formation of stable heptadecane from 8-heptadecene in the presence of abundant H2. The absence of H2 favored the cracking of 8-heptadecene. These cracked products were further converted to C8–C15 alkanes, for which a mass supply of hydrogen was mandatory. Gas-phase reactions including methanation, Fisher-Tropsch (F-T) synthesis, and water-gas shift (WGS) reactions between deoxygenated gas products and reaction media provided significant pathways for the hydrogen required for the formation of alkanes. The CH4 medium also acted as a hydrogen source due to its decomposition, catalyzed by nano-Ni/HZSM-5. Coke was substantially formed in all the four media. It was highlighted that the medium of H2 favored the formation of aliphatic cokes, whereas the non-H2 media, particularly the CO2 medium, facilitated aromatic coke species on account of its weak oxidizability. Additionally, there was a severe loss of loaded Ni nanoparticles under H2 medium but a slight Ni loss in CO2 medium, which was proposed to the reason of aromatic cokes formation at the catalyst surface, acting as a trap for the loaded Ni nanoparticles.

    更新日期:2018-08-26
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  • 更新日期:2018-08-26
  • The interaction between Fischer–Tropsch wastewater and humic acid: A NMR study of butanol isomers
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-23
    Hui Ma, Yan Qiao, Christian Marcus Pedersen, Pengfei Wang, Mengjie Wu, Pengfei Liu, Xianglin Hou, Tuoping Hu, Yingxiong Wang
    更新日期:2018-08-26
  • The effect of carbon dioxide on flame propagation speed of wood combustion in a fixed bed under oxy-fuel conditions
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-20
    J.K. Tanui, P.N. Kioni, T. Mirre, M. Nowitzki

    This paper presents an investigation of wood combustion in a laboratory-scale fixed bed with an aim of establishing the effect of CO2 environment on flame propagation speed and flame structures. Different oxy-fuel combustion atmospheres in which the composition of O2 in CO2 was varied from 21% to 50% by volume were tested and compared to air-fuel condition. Euler-Lagrange (Computational Fluid Dynamics - Discrete Element Method, CFD-DEM) approach which captures information of individual particle processes is used to model wood conversion in a packed bed. Results show that flame front propagation speed in oxy-fuel atmosphere reduced to 78% of that of the air-fuel condition with similar O2 concentration. For oxy-fuel conditions, propagation speed increased with increase in O2 concentration. The CFD-DEM model agrees very well with experimental values for mass loss, propagation speed and flame front positions. However, peak temperatures are poorly predicted at lower oxygen concentrations. The accuracy of temperature prediction improves at higher oxygen concentrations. During initial and devolatilization stage, mass fraction of tar predicted in CO2 environment are smaller than in N2 environment, while the amount of CO predicted is almost equal in both environments. However, during char combustion stage a high amount of CO is observed in oxy-fuel conditions.

    更新日期:2018-08-26
  • Impact of multi-hole-wall air coupling with air-staged technology on H2S evolution during pulverized coal combustion
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-19
    Honghe Ma, Lu Zhou, Suxia Ma, Shiliang Yang, Ya Zhao, Wei Zhang, Jia Wei Chew

    The multi-hole-wall air coupling with air-staged technology (MH&AS) was developed for pulverized coal combustion to affect a simultaneous realization of multiple benefits, including prevention of high-temperature corrosion, highly efficient burning of pulverized coal, and low NOx emissions. In this work, the impact of MH&AS on H2S evolution under different conditions was investigated by applying a laboratory-scale MH&AS furnace to test its feasibility for preventing high-temperature corrosion. Some important inclusions were obtained: (i) the lack of multi-hole-wall air for Daheng (DH) coal combustion resulted in H2S concentration exceeding the critical value (namely, 100 ppm) causing high-temperature corrosion, but H2S near the wall could be completely eliminated with a multi-hole-wall air ratio (αm) of 0.1; (ii) the higher the pyrite content of the coal sample was or the smaller the particle size, the larger the H2S concentration near the wall; (iii) the four reactions leading to H2S formation were validated by Gibbs free energy and chemical equilibrium constant calculations. This study affirms the efficiency of MH&AS in mitigating the high-temperature associated with air-staged combustion.

    更新日期:2018-08-26
  • Liquid hydrocarbon production via ethylene oligomerization over Ni-Hβ
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-19
    Oliver Jan, Fernando L.P. Resende
    更新日期:2018-08-26
  • Direct synthesis of dimethyl ether from CO and CO2 over a core-shell structured CuO-ZnO-ZrO2@SAPO-11 catalyst
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-19
    M. Sánchez-Contador, A. Ateka, A.T. Aguayo, J. Bilbao
    更新日期:2018-08-26
  • A kinetic study on char oxidation in mixtures of O2, CO2 and H2O
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-19
    Zehua Li, Liangkui Jiang, Juncheng Ouyang, Liang Cao, Guangqian Luo, Hong Yao

    Flue gas is usually recycled to a boiler during oxy-fuel combustion. Elevated levels of CO2 and steam in the recycled flue gas may affect coal combustion. To investigate the effect of H2O and CO2 on char oxidation, two kinds of Chinese coals, including YQ anthracite and SH lignite, were combusted in the mixtures of O2, CO2 and H2O atmosphere. The char conversion rates in different atmospheres were measured at the temperature of 1273 K. Further, H218O isotopic tracing method was adopted to clarify the reaction path of H2O. The results show that the shrinking core model is applicable to predict both combustion and gasification reactions in TGA. For both YQ and SH chars, char-O2 reaction is independent but char overall oxidation rate is promoted by the increase of H2O partial pressure. The active sites for char-O2 and char-H2O reactions are partly independent and partly at the same active sites for YQ anthracite, but they share common active sites for SH lignite. Char-H2O reaction is inhibited by char-O2 reaction but the 18O in H2O is still transferred to CO2 even in oxygen-rich atmosphere. The possible reaction may be C + H218O + 16O2 = C16O18O + H216O. However, CO2 has little influence on YQ char oxidation, but it has a slight promotion on SH char oxidation in low oxygen atmosphere at 1273 K. Also, the active sites for char-O2 and char-CO2 reactions are partly independent and partly at the same active sites for SH lignite, though the active site for char-CO2 reactions is few. Finally, a reaction kinetic model is purposed to predict char consumption rate in the mixtures of O2, CO2 and H2O.

    更新日期:2018-08-26
  • Prediction of wall impingement in a direct injection spark ignition engine by analyzing spray images for high-pressure injection up to 50 MPa
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-18
    Junkyu Park, Taehoon Kim, Donghwan Kim, Sungwook Park

    This study was performed to analyze the wall impingement and fuel film formation in a DISI engine with injection strategies using image-based analysis and CFD. The direct injection engine uses a high-pressure injection strategy to improve the homogeneity of the air-fuel mixture, so the spray behavior was analyzed by spray visualization for various injection pressures, and the wall impingement was predicted for various engine operating conditions based on the acquired images. The mass distribution of the injected fuel was calculated using the injection profiles and the spray image, and the amount of fuel that impinges on the piston and wall (i.e., the geometric boundaries of the cylinder) was calculated using data from the spray behavior for various engine operation conditions such as load and engine speed. The image-based analysis was limited to understanding the influence of the injection strategy on the droplet behavior after wall impingement of the fuel spray. Therefore, CFD using KIVA 3 V code was additionally conducted to analyze the effects of the injection strategies on wall film formation and droplet rebounding reflecting in-cylinder conditions. In the early- and late-injection conditions, the initial piston position is high, and most of the injected fuel impinges on the piston. As the injection pressure increases, the injection timing at which wall impingement occurs is advanced because of the rapid spray development. The results of the 3D analysis for the temperature and the intake flow in the engine cylinder showed that both the wall impingement and the fuel film were reduced as the injection pressure increased because the fuel evaporation increased due to improved atomization.

    更新日期:2018-08-26
  • Mechanical strength and combustion properties of biomass pellets prepared with coal tar residue as a binder
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-18
    Jun Cheng, Fan Zhou, Tingting Si, Junhu Zhou, Kefa Cen

    To reutilise the hazardous waste material coal tar residue (CTR) to bring environmental and economic benefits, CTR was first used as a binder to prepare biomass pellets with enhanced mechanical strength and heating values. CTR, which mainly contained asphaltenes (40.06%), aliphatics, aromatics and non-hydrocarbon components, had a high viscosity (72,276 mPa·s) and heating value (27.46 MJ/kg). When the CTR percentage increased from 0 to 40 wt%, the abrasive resistance of wheat straw, sawdust and moso bamboo pellets significantly increased from 10.62–69.20% to 95.66–98.24%, while their water resistance time increased from 6 s to >30 min and their heating value increased by 20.62–25.96%. The ignition temperature of wheat straw pellets increased from 275.7 to 280.7 °C as the CTR content increased from 0 to 30 wt%, whereas the maximum burning rate decreased from 1.28 to 0.82 mg/min and the burnout temperature increased from 465.33 to 563.33 °C.

    更新日期:2018-08-26
  • Progress on design and development of polymer electrolyte membrane fuel cell systems for vehicle applications: A review
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-17
    Guangjin Wang, Yi Yu, Hai Liu, Chunli Gong, Sheng Wen, Xiaohua Wang, Zhengkai Tu

    Due to its merit of rapid start-up, lower pollution and high energy conversion efficiency, polymer electrolyte membrane fuel cell (PEMFC) system has been considered as one of the most promising propulsion system for electric vehicles. Although the development of PEMFC system has been experienced rapid growth for several decades, many challenges still need to be overcome for promoting commercialize fuel cell technology. In order to understand the design concept of PEMFC system and update the development status of fuel cell system for electric vehicle, as well as help fuel cell system developers or electric vehicle manufacturers to improve the performance and durability of fuel cell electric vehicles, the up-to-date technical targets such as power density, operation temperature, dynamic response and lifetime for PEMFC systems in different countries have been summarized and compared in this review. Furthermore, from the aspects of hydrogen management and air management and major degradation mechanisms under various operation conditions, the design status of the system configuration in fuel cell has also been analyzed in detail. Finally, according to the design and intended operation the mitigation strategies have also been proposed to promote the development of PEMFC system for electric vehicle applications.

    更新日期:2018-08-26
  • Experimental study on combustion, flame and NOX emission of pulverized coal preheated by a preheating burner
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-14
    Ziqu Ouyang, Wen Liu, Chengbo Man, Jianguo Zhu, Jingzhang Liu

    Experimental researches on combustion characteristics of pulverized Ningdong bitumite preheated by a preheating burner were carried out in a 0.2 MW coal preheating combustion test rig, and the effects of preheating temperature, secondary air equivalence ratio and the positions of tertiary air nozzles on combustion, flame and NOX emissions of preheated fuels were studied. The results showed that the 0.2 MW coal preheating combustion test rig can operate stably and the combustion efficiency can be higher than 97% while the NOX emissions are lower than 100 mg/Nm3. With the increase of preheating temperature, NOX emissions increase, and the combustion efficiency does not change obviously. With the increase of secondary air equivalence ratio, the combustion efficiency increases, and NOX emissions increase as well. With the increase of the distance between the tertiary air nozzle and the preheated fuel nozzle, NOX emissions decrease, and the combustion efficiency decreases as well. The flame characteristic is not sensitive to preheating temperature, but closely related to the air distribution of down-fired combustor. With reasonable air supply positions, flameless combustion can be realized.

    更新日期:2018-08-26
  • Theoretical study of non-adiabatic counter-flow diffusion flames propagating through a volatile biomass fuel taking into account drying and vaporization processes
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-13
    Mehdi Bidabadi, Saman Hosseinzadeh, Mostafa Setareh, Pedram Panahifar, Sadegh Sadeghi

    Due to important advantageous of non-premixed flames such as controllability and safety, a proper investigation can be highly beneficial for application of these flames in medical and power generation industries. The current paper attempts to provide a promising analytical model for non-adiabatic counter-flow diffusion flames propagating through volatile biomass particles using an asymptotic method. In order to offer a reliable model for analysis of the flames, a multi-zone flame structure including preheat, drying, vaporization, reaction and oxidizer zones, is considered. In this work, lycopodium particles and air are taken as biofuel and oxidizer, respectively. For following the influences of effective dimensionless numbers, such as fuel and oxidizer Lewis numbers on the flame structure, dimensionalized and non-dimensionalized forms of mass and energy conservation equations are derived for each zone. In order to observe the heat loss effects, a linear term is added to the energy conservation equation. The conservation equations are solved by Mathematica and Matlab software applying accurate boundary and jump conditions. Finally, variations of flame temperature, flame front position, gaseous fuel and oxidizer mass fractions with fuel and oxidizer Lewis numbers, mass particle concentration, particle size, equivalence ratio and heat loss effect are elaborately elucidated.

    更新日期:2018-08-26
  • Oxidative removal of dibenzothiophene and related sulfur compounds from fuel oils under pressurized oxygen at room temperature with hydrogen peroxide and a phosphorus-free catalyst: sodium decatungstate
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-13
    Hisao Hori, Keisuke Ogi, Yuya Fujita, Yuta Yasuda, Eri Nagashima, Yusuke Matsuki, Kenji Nomiya

    We investigated the removal of dibenzothiophene (DBT) and related compounds, 4-methyldibenzothiophene (4-MeDBT), 4,6-dimethyldibenzothiophene (4,6-DMeDBT), 2,8-dimethyldibenzothiophene (2,8-DMeDBT), and 1-benzothiophene (1-BT) from several oil media at room temperature under pressurized O2 (0.6 MPa) by means of a three-phase reaction system consisting of the oil phase, an aqueous phase containing the phosphorus-free polyoxotungstate catalyst Na4W10O32·8H2O, H2O2, and tetraoctylammonium bromide, and the gas phase. Under conditions in which the initial DBT concentration in octane was 10.1 mM, the desulfurization ratio reached 87% after reaction for 6.5 h. The sulfur atoms in the initial DBT were well accounted for by the sulfur atoms in the residual DBT, the dibenzothiophene sulfone and dibenzothiophene 5-oxide in the octane phase, and the dibenzothiophene sulfone that precipitated. Prolonged reaction time to 18 h resulted in 92% desulfurization. The desulfurization of octane decreased in the order 2,8-DMeDBT ~ DBT > 4-MeDBT >1-BT ~ 4,6-DMeDBT. Light oil and kerosene could also be desulfurized efficiently: after reaction for 6.5 h, the desulfurization ratios reached 77 and 78% for light oil and kerosene, respectively.

    更新日期:2018-08-26
  • Sequential extraction of oak wood sawdust and oxidative degradation of the extraction residue
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-11
    Xiao-Li Xue, Zhi-Min Zong, Hong-Lei Yan, Quan-Xi Zheng, Ling-Yao Kong, Xian-Yong Wei

    Oak wood sawdust (OWSD) was extracted under supercritical CO2 sequentially with petroleum, carbon disulfide (CDS), methanol, acetone, and isometric CDS/acetone mixture to afford extracts 1–5 (E1–E5), respectively. Then the extraction residue (RE) was subjected to sequential oxidation with aqueous hydrogen peroxide (AHPO)/acetic anhydride (AAH) at 65 °C to afford soluble portions 1–4 (SP1–SP4). In total, ca. 95.8% of organic matter in OWSD became soluble by the sequential extraction and oxidation. No significant difference in the distribution of functional groups was observed in Fourier transform infrared spectra of OWSD and RE, while the distribution of functional groups in the oxidation residue is significantly different from that in either OWSD or RE. In total, 117 and 168 compounds were detected in E1–E5 and SP1–SP4, respectively, with a gas chromatograph/mass spectrometer. E1–E5 are rich in esters, while carboxylic acids are abundant in SP1–SP4 in addition to esters. HO· released from AHPO/AAH played a crucial role in oxidatively degrading RE.

    更新日期:2018-08-26
  • Pyrolysis and gasification studies of model refuse derived fuel (RDF) using thermogravimetric analysis
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-06
    Sireesha Aluri, Akil Syed, Derrick W. Flick, John D. Muzzy, Carsten Sievers, Pradeep K. Agrawal

    Processing Municipal Solid Waste (MSW) into a Refuse Derived Fuel (RDF) reduces experimental variability and improves handling. This study analyzes the pyrolysis of individual components to define the model components that mimic real RDF. Size reduction and effective mixing of nine components of model RDF composition allow for reproducible results in lab scale experiments. Selected individual components as well as the model RDF composite are converted by pyrolysis and gasification at 800 °C with a 20 K/min heating rate. The pyrolysis results show that the decomposition profile, product yields, heat of decomposition, and gas composition of the model RDF can be predicted by adding the corresponding values of the individual components in the required proportions. The inorganic content of the individual component chars is found to have a profound effect on the gasification reactivities. Potassium and calcium have the largest catalytic effect during gasification, while silicon and phosphorous inhibit gasification. Potassium mobility and redistribution from orange peels in the model RDF to the other components is determined to be chiefly responsible for the synergistic gasification profile of the char. Furthermore, synergy is observed at different particle size ranges (<106 μm and 0.6–0.8 mm) tested. However, the extent of synergy varies in the two cases leading to different reaction times for complete conversion.

    更新日期:2018-08-26
  • Biobased chemicals from the catalytic depolymerization of Kraft lignin using supported noble metal-based catalysts
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-04
    I. Hita, P.J. Deuss, G. Bonura, F. Frusteri, H.J. Heeres
    更新日期:2018-08-26
  • Improved catalytic upgrading of simulated bio-oil via mild hydrogenation over bimetallic catalysts
    Fuel Process. Technol. (IF 3.956) Pub Date : 2018-07-03
    Junhao Chen, Shurong Wang, Liang Lu, Xing Zhang, Yixi Liu
    更新日期:2018-08-26
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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