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  • An index of fluidity-temperature area for evaluating cohesiveness of coking coal by Gieseler fluidity characterization
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-11
    Guangzhi Yang, Ting Shi, Qifeng Zhang, Yinping Cao, Weiji Zhang, Xinci Wu, Jing Li, Junhe Yang

    Gieseler fluidity characterization is an important method to evaluate the fluidity of coal which highly influences the cohesive properties of coke formation. A concept of fluidity-temperature area SlgF instead of maximum fluidity lgMF was put forward to be used as the index of Gieseler fluidity characterization. Thirty-five coal samples were tested by Gieseler characterization and the sensitivity for identifying coal cohesiveness by SlgF and lgMF were compared. It was found that SlgF has a more sensitive resolution of coal fluidity than lgMF and it could give a correct result for judging coal cohesiveness in accordance with the comprehensive cohesiveness in most cases, especially for coals having almost same lgMF values.

    更新日期:2018-04-17
  • 更新日期:2018-04-17
  • Understanding the unusual fluidity characteristics of high ash Indian bituminous coals
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-10
    Bidyut Das, A. Suresh, Pratik Swarup Dash, Sanjay Chandra, Miguel Castro Díaz, Lee A. Stevens, Colin E. Snape

    High-temperature rheometry and 1H nuclear magnetic resonance (NMR) are two complementary techniques that have been used to investigate fluidity development quantitatively in the <53 μm and 53–212 μm size fractions of high ash Indian non-coking coals and imported non-coking, medium coking and good coking coals. It was found for the 53–212 μm size fraction of the Indian bituminous coal with higher ash content (30 wt%) that, despite its high complex viscosity (>105 Pa·s), the maximum concentration of fluid H was quite similar to that of the good coking coal (40%). This Indian non-coking coal developed fluid H with the highest mobility (T2L > 150 μs) in the coal series, regardless of the particle size fraction studied. The probable explanation for this abnormal behavior is that the mineral matter prevents bulk movement in the sample but the local mobility of the fluid phase is still high on the nanometer scale. Blending the two Indian non-coking coals with the highly fluid medium coking coal gave higher viscosities (i.e. lower fluidity) than predicted by the polymer blend rule, probably again due to the high mineral matter restricting bulk flow. This negative effect was less pronounced with the higher ash coal suggesting that the high mobility of the fluid entities in this coal might prevent the destruction of fluid entities evolving from the medium coking coal. Partial demineralization of the high ash Indian non-coking coal to 17 wt% through a sink-float method did not decrease the complex viscosity of this coal but reduced the maximum mobility of the fluid H to levels observed with the lower ash content (20 wt%) Indian coal. Therefore, this reduction in mobility could be directly related to the mineral matter in the Indian non-coking coal.

    更新日期:2018-04-11
  • Adsorption and dispersion performance of oxidized sulfomethylated kraft lignin in coal water slurry
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-10
    Mohan K.R. Konduri, Pedram Fatehi

    In this study, oxidized and sulfomethylated lignin (OSL) with the charge density of −4.4 meq/g was used as a dispersant for coal water slurry (CWS). The impact of the OSL on CWS having different particle sizes was fundamentally investigated. The size of particles greatly influenced the adsorption of OSL on coal particles and the rheology and stability of the CWS. The maximum adsorption of OSL was found to be 0.96 mg/g on coal A having the particle size of 22 μm (coal particles with smallest size). OSL improved the wettability of coal by 5–28%. The interfacial tension between coal particle and OSL was reduced from 17 mN/m to 13 mN/m, and the zeta potential of the suspension dropped from −30 mV to −47 mV when 0.96 mg/g of OSL was adsorbed on coal A. The addition of 64 mg/L of OSL to coal A suspension (50 wt%) reduced its viscosity from 1350 to 520 mPa·s. The stability of coal particles was also improved as the destabilization index of CWS was reduced from 4 to 0.2. These results confirmed that the OSL was an effective dispersant for the coal water slurry.

    更新日期:2018-04-11
  • Confinement of microporous MOF-74(Ni) within mesoporous γ-Al2O3 beads for excellent ultra-deep and selective adsorptive desulfurization performance ☆
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-11
    Zipeng Zhao, Zareen Zuhra, Libo Qin, Yunshan Zhou, Lijuan Zhang, Fang Tang, Cuncun Mu
    更新日期:2018-04-11
  • Catalytic upgrading of coal pyrolysis products over bio-char
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-07
    Da-qing Fu, Xiao-hong Li, Wen-ying Li, Jie Feng

    Several reactions parallel happened during co-pyrolysis of coal and biomass, such as primary volatiles of coal and biomass will contact and react with the nascent char from coal or biomass themselves' pyrolyzed. To clarify the function of bio-char and investigate if bio-char has the catalytic effect on pyrolysis products of Hulunbuir lignite, a two-stage reactor is designed and used in this study. The effects of bio-char preparing temperature, char-making method and usage amount of bio-char were discussed. In comparison with the alone coal pyrolysis at 650 °C, the portion of light tar (n-hexane soluble) from pyrolysis of coal with bio-char (20 wt% of coal), increased by 30.31%, gas volume yield increased by 9.05% and the volume yield of hydrogen and methane increased by 6.36% and 5.64%, respectively. For the most efficient RSCR-700 against the test with quartz, the H/C molar ratio in RSCR-700's produced tar increased by 22.06%, while the contents of N and S elements decreased by 27.88% and 25.0% accordingly. The role of bio-char in the coal tar upgrading process was further explored through the instruments characterization. Besides the thermal cracking, the bio-char also can provide catalytic active sites to crack heavy fraction of coal tar.

    更新日期:2018-04-10
  • Regioselective hydrogenolysis of alga-derived squalane over silica-supported ruthenium‑vanadium catalyst
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-09
    Yosuke Nakaji, Yoshinao Nakagawa, Masazumi Tamura, Keiichi Tomishige

    Addition effect of 2nd metal to Ru catalysts in hydrogenolysis of squalane was investigated. Addition of V gave lower methane selectivity and higher C14-C16 selectivity and the effect was the most remarkable over SiO2 support. However, addition of V decreased the catalyst activity and increased the deposited amount of carbonaceous species. From hydrogenolysis of n-hexadecane, addition of V suppressed the formation of methane via terminal C single bond C bond dissociation, but the formation via fragmentation was not suppressed. Ru and V valences in Ru-VOx/SiO2 (V/Ru = 0.25) after reduction were 0 and +III, respectively. The size of Ru particles was about 4 nm from XRD even in changing V/Ru ratio. H2 chemisorption showed that V covered the Ru particles and reduced the size of Ru ensemble. In reuse test, it was difficult to retain the catalyst performance for hydrogenolysis of squalane even with various treatments of the recovered catalyst such as washing with n-hexane, heating in N2 flow or calcination in air. From XAS analysis, the contact of Ru particles with air caused the aggregation of Ru metal especially when calcined in air.

    更新日期:2018-04-10
  • Efficient production of furfural from xylose and wheat straw by bifunctional chromium phosphate catalyst in biphasic systems
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-07
    Siquan Xu, Donghui Pan, Yuanfeng Wu, Xianghai Song, Lijing Gao, Wenqi Li, Lalitendu Das, Guomin Xiao

    We present here a study of the production of furfural from xylose and wheat straw using the chromium phosphate (CrPO4) with Lewis and Brønsted acidity as a highly efficient catalyst in the water/tetrahydrofuran (THF) biphasic system. The effects of various reaction parameters including reaction temperature, reaction time, system, and catalyst dosage were explored to evaluate the product yield. Under CrPO4 catalysis, an excellent furfural yield could reach 88% from the xylose at 160 °C for 60 min. Meanwhile, 67% furfural and 32% 5‑hydroxymethylfurfura (HMF) were simultaneously achieved from wheat straw at 180 °C for 90 min. Mechanistic studies suggested that the perfect catalytic activity of CrPO4 was due to its inherent bifunctional catalysis activity. It was found that the CrPO4 was easily to be recovered and a great catalytic activity was available after four cycles, which not only contributed to a sustainably reduced energy consumption on catalyst recovery, but also reduced the concerns associated with toxic chromium element.

    更新日期:2018-04-10
  • Evolution of heavy components during sewage sludge pyrolysis: A study using an electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-07
    Song Hu, Hengda Han, Syed Shatir A. Syed-Hassan, Yani Zhang, Yi Wang, Liangping Zhang, Limo He, Sheng Su, Long Jiang, Junfeng Cheng, Jun Xiang

    Heavy components affect conversion behaviors of sludge-derived pyrolytic liquids during their utilization and contribute significantly to the formation of the notorious tar and soot during sludge gasification and combustion. Understanding the evolution of heavy components during pyrolysis is vital for developing a reliable sewage sludge utilization technology. This study investigates the compositions of oils from the pyrolysis of sewage sludge using an electrospray ionization Fourier transform ion cyclotron resonance mass spectrometry (ESI FT ICR-MS). Hundreds of compounds with molecular mass higher than 400 Da were detected from the pyrolytic oil obtained at 450 and 650 °C. Higher pyrolysis temperatures promoted decomposition and polycondensation of large molecules and increased the amount of nitrogen-containing compounds in the liquid. Aromatic structured molecules consisting of carbon, hydrogen and nitrogen were the predominant compounds at 850 °C. From the results of this study, the evolution routes of heavy components in the pyrolytic liquid are proposed.

    更新日期:2018-04-10
  • Combustion characteristics of syngas on scaled gas turbine combustor in pressurized condition: Pressure, H2/CO ratio, and N2 dilution of fuel
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-09
    Seik Park, GyungMin Choi, Mamoru Tanahashi

    To facilitate fuel interchangeability for industrial gas turbines, various kinds of fossil fuels including syngas from coal gasification and steel mill gases including Blast Furnace Gas (BFG) have been investigated by previous researchers to determine their viability as alternative fuels for power generation. In the present study, various syngas components produced from coal gasification were combined to produce a simulated mixed gas, which was fed into a pressurized gas turbine combustion test rig to determine the combustion characteristics. A scaled model of the 7EA combustor from GE was used to conduct a basic comparative study on the emission trend (NOx), exhaust gas temperature distribution according to the combustor pressure, syngas composition and dilution ratio at the fuel side. The major findings were that modification of the empirical formula for pressure affects NOx emission and nitrogen dilution ratio affects the temperature profile uniformity on the fuel side.

    更新日期:2018-04-10
  • Experimental study on thermo-responsive inhibitors inhibiting coal spontaneous combustion
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-09
    Chuanbo Cui, Shuguang Jiang, Hao Shao, Weiqing Zhang, Kai Wang, Zhengyan Wu

    Due to its strong fluidity and easy evaporation characteristic, high water-cut physical inhibitors (HWPIs) cause the decrease in moisture content of coal, so that its inhibitory effect on coal spontaneous combustion weakens or even fails. Aiming at solving the problem, this paper proposes to inhibit coal spontaneous combustion using thermo-responsive inhibitors (TRIs). These inhibitors are sensitive to specific temperatures and can retain their effects as long as the temperatures have not been reached. Besides, when the temperatures are reached, they are able to absorb heat and undergo physical and chemical changes to release H2O and inert gases (defined as gases that are not involved into the coal oxidation reaction in this paper) such as NH3 and CO2, so as to inhibit the low-temperature oxidation of coal. Based on the temperature-programmed experiment of coal spontaneous combustion, this paper analyzed the effects of types and amounts of TRIs on coal spontaneous combustion by using differential scanning calorimetry (DSC), scanning electron microscope (SEM), thermogravimetry-derivative thermogravimetric analysis-differential scanning calorimetry (TG-DTG-DSC) and nitrogen adsorption test methods. The results show that CaCl2•6H2O achieves the most stable inhibitory effect, as its inhibiting rate rises steadily in the heating process to reach a maximum value of 79.9% at 200 °C.

    更新日期:2018-04-10
  • Modeling pyrolytic behavior of pre-oxidized lignin using four representative β-ether-type lignin-like model polymers
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-06
    Weikun Jiang, Jiangyong Chu, Shubin Wu, Lucian A. Lucia

    A better understanding of the pyrolytic characteristics of pre-oxidized lignin in which CαH–OH was oxidized to Cα<img border="0" alt="double bond; length as m-dash" src="https://cdn.els-cdn.com/sd/entities/dbnd">O group was obtained through four selected β-ether-type lignin-like model polymers containing the H- and G-type subunits. These models were depolymerized in closed ampoule reactor system and interrogated using in-situ FTIR. The results show that their degradation products differ significantly in species and yield due to CαH–OH, Cα<img border="0" alt="double bond; length as m-dash" src="https://cdn.els-cdn.com/sd/entities/dbnd">O, and aryl–OCH3. The yield of phenolic monomers from oxidized G-type polymer rose to 27.87 wt%, almost twice that of initial G-type polymer. Nevertheless, as for H-type polymer, oxidation of the CαH–OH to Cα<img border="0" alt="double bond; length as m-dash" src="https://cdn.els-cdn.com/sd/entities/dbnd">O group lead to decreases in phenolic monomers yield by ~half. The in-situ FTIR indicates that oxidation of the CαH–OH to Cα<img border="0" alt="double bond; length as m-dash" src="https://cdn.els-cdn.com/sd/entities/dbnd">O accelerates cleavage of interunit linkages and simplifies depolymerization pathways resulting in better selectivity of phenolic monomers, especially at low pyrolysis temperatures (<500 °C). Several important transformation pathways are proposed that clearly explain the pyrolytic behavior of pre-oxidized polymers.

    更新日期:2018-04-08
  • A comparison of partially burnt coal chars and the implications of their properties on the blast furnace process
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-06
    J.M. Steer, R. Marsh, D. Sexton, M. Greenslade

    Blast furnace coal injection is a vital part of modern ironmaking, reducing the amount of coke reductant required in the process and increasing its efficiency. However the injection of different coals or their blends, into the raceway formed by the hot blast, has technical issues due to the very short particle residence times and the limited availability of oxygen in this region. This makes complete burnout difficult and limits the range of coals suitable for this application, leading to partially burnt chars being carried out of the raceway into the blast furnace shaft and potentially into the off-gas system.This paper explores the fate of these chars, from a range of different coals, looking at how this influences the selection for injection and the implication of these on the blast furnace. In particular, we have looked beyond the limitations of selecting coals based on proximate analysis alone by examining in more detail other physical and chemical properties and their potential effect on the process. A drop tube furnace (DTF) has been used to synthesise chars in a high heating rate environment, and although burnout and volatile loss values suggest suitability of some coals for blast furnace injection, additional problematic effects have been identified and measured such as char swelling and agglomeration which may impact the gas permeability of the furnace. A TGA/DSC has been used to measure the gasification of chars by the Boudouard reaction and compare the thermal impact of more reactive samples.While other studies have concentrated on the combustion of injection coals to determine their suitability, this one focuses on the implications of the partially burnt chars formed by incomplete reaction in the raceway.

    更新日期:2018-04-08
  • Rapid beneficiation of fine coal tailings using a novel agglomeration technology
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-04
    K. van Netten, K.P. Galvin

    Froth flotation has been used successfully over the last century for the beneficiation of coal and mineral particles. However, the process has been affected by certain restrictions relating to the rate at which the bubble/particle concentrate segregates from the aqueous tailings and to the recovery of ultrafine particles. An alternative separation technique, which appears to have the potential to remove these limitations, is selective agglomeration using a high internal phase emulsion binder. Presented in this paper are the findings from an investigation into the continuous steady state processing of fine coal tailings using the emulsion binder. This coal was sourced from a hydrocyclone overflow and had an ash% of 42%. The results from the experiments are compared to the results obtained from a batch system. It was found that both systems achieved a high combustible recovery of 70–80% and low product ash of 15–17%, however, the continuous process needed at least 15% less organic liquid to achieve agglomeration. Moreover, filtration of the agglomerated product material subjected to further high shear demonstrated low moistures of approximately 16 wt%. Therefore, it appears that agglomeration using the emulsion binder offers a method for producing valuable products from fine coal tailings.

    更新日期:2018-04-06
  • Biomass pellet combustion: Cavities and ash formation characterized by synchrotron X-ray micro-tomography
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-05
    Anna Strandberg, Mikael Thyrel, Nils Skoglund, Torbjörn A. Lestander, Markus Broström, Rainer Backman
    更新日期:2018-04-06
  • Further exploring on aqueous chemistry of micron-sized lignite particles in lignite–water slurry: Effects of humics adsorption
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-03
    Wencui Chai, Wenjuan Wang, Yanfang Huang, Guihong Han, Yijun Cao, Jiongtian Liu
    更新日期:2018-04-04
  • Using two-zone fluidized bed reactor in propane aromatization over Zn/HZSM-5 catalyst
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-04
    Abbas Roshanaei, Seyed Mehdi Alavi

    Propane conversion to aromatics was carried out in a two-zone fluidized bed reactor (TZFBR) over Zn/HZSM-5 catalyst. At the steady state condition the coke formation in the TZFBR was counteracted with continuous catalyst regeneration by oxygen. In the lower part of the reactor, the oxidation and combustion of deposited coke on the catalyst surface were achieved with a necessary amount of oxygen. The aromatization reaction takes place in the upper part. In order to ensure the stability of the TZFBR performance, the propane aromatization was carried out in the conventional fluidized and fixed bed reactors in the absence of oxidant. Because of the catalyst regeneration, the high propane conversion and selectivity to aromatics were obtained in the TZFBR. The effects of the main operating variables such as: O2 mole percentage, height of the propane feed entry point, bed temperature and relative velocity were studied and the optimum experimental conditions were considered.

    更新日期:2018-04-04
  • Combustion characteristics and kinetic analysis of heavy tar from continuous pyrolysis of camellia shell
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-03
    Mingfeng Wang, Zhiwen Chen, Juan Lv, Yongzhi Ren, Yang Jiang, Enchen Jiang, Donghai Wang

    The objective of this research was to study the combustion kinetics of heavy tar from continuous pyrolysis of camellia shell. TG-DSC was used for combustion study with heating rates of 10, 20, and 30 °C/min, temperatures from 26 to 800 °C, and air flowrate of 100 mL/min. Results showed that the combustion process, with three stages, includes low-boiling components volatilization, light components decomposition and combustion, and heavy components and char combustion. The correlation among heating rate, maximum mass loss rate and mass loss ratio and the combustion behaviors at each stage with different heating rates were analyzed. The activation energy and frequency factor of each stage were obtained by Friedman and Ozawa methods. The reaction mechanisms are the random nucleation and growth, and the kinetic parameters were obtained by fitting experiment data with theoretical models. The mechanisms and kinetic parameters obtained could be used to describe the heavy tar combustion.

    更新日期:2018-04-03
  • New insight into the chemical structures of Huadian kerogen with supercritical ethanolysis: Cleavage of weak bonds to small molecular compounds
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-03
    Qing Liu, Yucui Hou, Weize Wu, Qian Wang, Shuhang Ren, Qingya Liu

    Oil shale is a potential alternative fossil energy source. The chemical structure of oil shale kerogen is the basis of its application, presently for retorting to yield shale oil and gas. Supercritical ethanolysis is a kind of chemical extraction which can effectively depolymerize organic matter like coal and lignin through breaking some weak bonds. In this work, new insights into weak bonds (including O-containing, N-containing and S-containing functional groups) of the chemical structures of Huadian kerogen (HDK) were obtained with supercritical ethanolysis, and the resulted products, small molecular compounds (SMCs), were identified. It was found that, after ethanolysis at 375 °C, 87.4% of HDK was converted by breaking the weak bonds to SMCs, including aliphatic acid esters, aliphatic acids, alkanes, alcohols, aromatics, N-containing organic compounds (NCOs), and S-containing organic compounds (SCOs). In the SMCs, there are 52.0% aliphatic acid esters and aliphatic acids with carbon numbers from 4 to 26, 11.4% alkanes with carbon numbers from 14 to 22, 19.1% aromatic compounds with single-ring and double-ring aromatic clusters, 5.4% alcohols, 5.0% NOCs, 1.9% SCOs, and 5.4% biomarkers. FTIR and 13C NMR were used to characterize the changes of HDK and its residues, which further demonstrate that the SMCs are present and connected with weak bonds to solid aromatic clusters insoluble in ethanol. During the pyrolysis of oil shale, these weak bonds are first broken and the above SMCs are produced in molecular or radical states, which are the most compounds from the primary reactions and readily undergo the second reactions to yield oil and gas.

    更新日期:2018-04-03
  • Xylan/DBU as an efficient and green catalyst for chemical fixation of CO2
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-03
    Qiu-sheng Zhou, Xin-wen Peng, Lin-Xin Zhong, Xue-hui Li, Wei-tian Chua, Run-cang Sun
    更新日期:2018-04-03
  • Design of active and stable bimodal nickel catalysts for methane reforming with CO2
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-03
    Baitao Li, Xiaorong Lin, Yao Luo, Xiaoqing Yuan, Xiujun Wang
    更新日期:2018-04-03
  • Study on the thermal liquefaction of Xilinguole lignite in solvent at high temperature
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-03
    Zhicai Wang, Lei Li, Runan Hu, Xiaoling Wang, Chunxiu Pan, Shigang Kang, Shibiao Ren, Zhiping Lei, Hengfu Shui

    In this paper, thermal liquefaction (TL) of Xilinguole lignite (XL) in the range of 400–540 °C have been carried out in toluene, tetralin (THN) and their mixed solvent, respectively. Results indicated that the conversion of XL primarily depends on the hydrogen donor ability of solvent. The highest conversions of XL in toluene and THN were obtained at 480 °C, which are 25.8% and 98.6%, respectively. The condensation of pyrolytic free radicals dominates the TL in toluene solvent but there is hardly obvious coking occurred in THN at below 510 °C. In toluene and THN mixed solvent, the conversion of XL increases with the THN content. The products of TL in toluene mainly consist of oil and gas (O + G) fraction, but the asphaltene (AS) and preasphaltene (PA) factions prevail in the products of TL in THN. Hydrogen donor solvent has obvious improvement on the deoxygenation in the TL process. Therefore, TL in hydrogen donor solvent is a potential conversion technology of XL due to low reaction pressure and without H2 and catalyst used.

    更新日期:2018-04-03
  • Kinetic analysis on the microwave drying of different forms of water in lignite
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-03
    Chao Li, Jun-Jie Liao, Yang Yin, Qiong Mo, Li-Ping Chang, Wei-Ren Bao

    A Chinese raw lignite with total water (RC) and molecular water (MWC) were prepared. Those samples were dewatered by a microwave drying equipment using constant power selected from 450–600 W. The first order reaction kinetic equation and ten thin-layer drying models were used to analyze the dewatering processes of MWC and RC respectively. Moreover, the effective diffusion coefficient of water, the activation energy of the water removal and the drying rate constant (k) were calculated. The first order reaction kinetic equation and the Two-term exponential model provided a better fit for the drying processes of MWC and RC respectively. The effective diffusion coefficient of water obtained by Fick's second law varies from 0.3708 × 10−8 to 1.6715 × 10−8 m2·min−1 for MWC and from 0.5099 × 10−8 to 3.3169 × 10−8 m2·min−1 for RC. The activation energy for the removal of the molecular water is 28.59 kJ·mol−1, and that for the total water is 24.25 kJ·mol−1. The k of MWC and RC are in the range of 0.0894–0.4364 min−1 and 0.2737–1.4740 min−1 respectively. From the energy consumption aspects, it is suggested the microwave power higher than 550 W should be used to remove the free water and capillary water, and 525 W used to remove the molecular water.

    更新日期:2018-04-03
  • Effect of thermophysical properties of heat carriers on performance of a laboratory-scale auger pyrolyzer
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-04-03
    Tannon J. Daugaard, Dustin L. Dalluge, Robert C. Brown, Mark Mba Wright

    This study evaluated the effect of thermophysical properties of heat carriers on the performance of a laboratory-scale auger reactor. Heat carriers tested included stainless steel shot, fine sand, coarse sand and silicon carbide. The results showed similar organic yield and composition of bio-oil among the heat carriers when pyrolyzing red oak. Significant differences in yields of reaction water, char and non-condensable gases were observed. It was also found that residual carbon contributed to as high as 20 wt% of total char yield and attrition of heat carrier as high as 7% on a mass basis were present after as little as 2 h of operation. Tradeoffs between physical performance, material cost, and product yields may exist when selecting heat carrier materials for pyrolysis of biomass in an auger reactor.

    更新日期:2018-04-03
  • 更新日期:2018-03-30
  • Assessment of the improvement of chemical looping combustion of coal by using a manganese ore as oxygen carrier
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-30
    Alberto Abad, Pilar Gayán, Teresa Mendiara, José A. Bueno, Francisco García-Labiano, Luis F. de Diego, Juan Adánez

    Finding suitable low-cost materials to be used as oxygen carrier in Chemical Looping Combustion (CLC) of coal is a key issue to achieve the CO2 capture at low economic cost. Recently, a Mn-ore from Gabon has been identified as an alternative to the state of the art of oxygen carriers based on minerals or wastes with high iron content. This Mn-ore showed a high reactivity and a long particle lifetime during batch characterization to be considered as a suitable oxygen carrier. To evaluate the potential of this material in CLC, this work analyses the behaviour of the Mn-ore during continuous combustion of a bituminous coal in a 0.5 kWth CLC unit. The CLC process was evaluated and the effect of the main operating variables - such as fluidizing medium, oxygen carrier circulation rate, temperature, and solids inventory in the fuel reactor - on the combustion efficiency and CO2 capture was investigated. A direct relation between the char conversion rate and the CO2 capture is given, being mainly affected by the mean residence time of solids and temperature in the fuel reactor. The use of a carbon separation system with separation efficiency above 90% would be required to achieve CO2 capture rates higher than 95%. Total oxygen demand values as low as 4.5% were found when optimal operating conditions were selected, mainly being related to oxygen carrier to fuel ration higher than ϕ > 3. At these conditions, the Mn-ore material showed similar combustion efficiencies than other Fe-based low-cost materials previously tested, but with higher CO2 capture rates.

    更新日期:2018-03-30
  • Tandem mass spectrometric evaluation of core structures of aromatic compounds after catalytic deoxygenation
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-30
    Xing Fan, Guo-Sheng Li, Xueming Dong, Jing Jiang, Xian-Yong Wei, Hilkka I. Kenttämaa

    Catalytic deoxygenation of coal enhances the stability and combustion performance of coal-derived liquid fuels. However, determination of the selectivity of removal of oxygen atoms incorporated in or residing outside of aromatic rings is challenging. This limits the ability to evaluate the success of catalytic deoxygenation processes. A mass spectrometric method, in-source collision-activated dissociation (ISCAD), combined with high resolution product ion detection, is demonstrated to allow the determination of whether the oxygen atoms are in aromatic compounds reside outside of aromatic rings or part of the aromatic system, because alkyl chains can be removed from aromatic cores via ISCAD. Application of this method for the analysis of a subbituminous coal treated using a supported catalyst revealed that the catalytic treatment reduced the number of oxygen-containing heteroaromatic rings but not the number of oxygen atoms residing outside the aromatic rings.

    更新日期:2018-03-30
  • NH3 inhibits mercury oxidation over low-temperature MnOx/TiO2 SCR catalyst
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-30
    Hailong Li, Jiexia Zhao, Weilin Zhang, Jianping Yang, Jun Wang, Mingguang Zhang, Zequn Yang, Liqing Li, Kaimin Shih
    更新日期:2018-03-30
  • The effect of water addition on the surface energy, bulk and flow properties of lignite
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-27
    Yong Jin, Hai-Feng Lu, Xiao-Lei Guo, Xin Gong
    更新日期:2018-03-28
  • Effect of Ca(NO3)2 addition in coal on properties of activated carbon for methane decomposition to hydrogen
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-26
    Jiaofei Wang, Lijun Jin, Yang Zhou, Yang Li, Haoquan Hu

    Activated carbon (AC) was prepared from a subbituminous coal with addition of Ca(NO3)2 by KOH activation, and used for catalytic methane decomposition to produce hydrogen. The effects of calcium addition amount on the structure and catalytic performance of the resultant ACs were investigated. As the addition of Ca(NO3)2, the surface area and pore volume of ACs increase significantly compared with that of AC without addition, especially the mesoporous surface area improved from 480 m2/g to 1119 m2/g. Almost hyaline structure of carbons are obtained when a high amount of calcium is added into the coal. The addition of calcium in coal leads to the significant increase of methane conversion over the resultant carbon catalysts, and when the calcium addition amount is 15 wt%, the prepared AC has the highest mesoporous surface area and the best stability. No direct relationship was found between specific surface area and the activity of carbons, but the mesopores benefit the stability of ACs in methane decomposition. Carbon fiber was produced on AC from the coal with addition of calcium compared with the aggregated carbon on that from coal without addition of calcium.

    更新日期:2018-03-27
  • Effect of stannous chloride on low-temperature oxidation reaction of coal
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-23
    Botao Qin, Guolan Dou, Xiaoxing Zhong

    Stannous chloride (SnCl2) was firstly used as an inhibitor to prevent coal oxidation. Thermal analysis was used to study the influence of SnCl2. Weight increase due to oxygen chemisorption, the ignition temperature, the burnout temperature and heat released during the whole process were evaluated as main parameters. The results indicated that the addition of SnCl2 leads to significant reduction in the percentage of mass increase. The presence of SnCl2 caused increase in the ignition temperature and decrease in the heat released. However, there is probably no effect of SnCl2 on the burnout temperature. The mechanism of the SnCl2 suggested that the addition of SnCl2 to the coal oxidation mainly influence the oxygen chemisorption by consuming more oxygen. Thus, SnCl2 can be recommended as effective inhibitor to coal oxidation.

    更新日期:2018-03-24
  • Prediction of ash fusion behavior from coal ash composition for entrained-flow gasification
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-23
    Thulasi Sasi, Moein Mighani, Evrim Örs, Ruchika Tawani, Martin Gräbner

    In entrained-flow gasification, solid fuel is brought in contact with oxygen and steam, yielding slagging conditions at temperatures of 1250–1800 °C. The process temperature cannot be chosen freely but is determined by the melting behavior of the coal ash. By blending different coals and fluxing agents, the ash fusion temperature can be lowered allowing operation at a lower reactor temperature and savings in oxygen. Since ash fusion behavior is not measurable online, it can be beneficial to use a quickly measured coal ash composition and estimate the ash fusion behavior instantly. In this work, >300 different coal samples from all over the world were investigated. This includes ash compositions determined from X-ray fluorescence (XRF) analysis and standard ash fusion behavior under reducing and oxidizing conditions. In a systematic approach, the ash components were limited to the most significant ones to optimize calculation time. The software ChemApp was used to calculate thermodynamic equilibrium based on FToxid and FactPS databases. The obtained results involve the temperatures at which 10 to 100% of the ash melt are liquid slag calculated in 10%-pts steps. According to the applied atmosphere, the obtained results have been statistically correlated to the experimentally determined fusion temperatures. In parallel, a neural network approach was tested to accomplish the same task. It was found that the hemispherical temperature correlates best to a liquid slag fraction of 85.0 wt% under reducing and 80.1 wt% under oxidizing conditions. The thermodynamic model is able to predict the hemispherical temperature under reducing conditions for 32% of the data while exclusion criteria defining the validity range have been formulated. The neural network model shows in average a higher accuracy of predicting ash fusion behavior from ash composition covering also temperatures of initial deformation and fluidity and appears as a suitable alternative to the thermodynamic calculation if sufficient data are available (i.e. covering the coal ash composition range of interest).

    更新日期:2018-03-24
  • Production of activated carbon from peat by with natural soda ash and effect of nitrogen addition on the development of surface area
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-23
    Naoto Tsubouchi, Megumi Nishio, Yuji Shinohara, Javzandolgor Bud, Yuuki Mochizuki

    The optimum conditions for the production of high-surface-area activated carbon from peat were examined in a fixed-bed quartz reactor by using natural soda ash (>99 mass% Na2CO3) as the activation agent and urea (CH4N2O) as the nitrogen source. In the heating of the peat/urea/Na2CO3 mixture, the surface area of activated carbon significantly increased when the temperature was higher than 700 °C, and it reached 940 and 1100 m2/g at 800 and 900 °C, respectively. When the mixture was also held at 700 and 800 °C for 1 h, the surface area drastically increased from 100 m2/g without holding treatment to 730 m2/g at 700 °C, and it became 1050 m2/g at 800 °C. The effect of the peat/urea/Na2CO3 mixing ratio on the increase in surface area was investigated. The ratio of urea to Na2CO3 was fixed at 1/2 and the proportion of peat was varied in the range of 0.5–2; the surface area was maximum when peat = 1. In another case, the ratio of peat to urea was fixed at 1/1 and the proportion of Na2CO3 was varied in the range of 1–4. In this case, the surface area was maximum (940 m2/g) when Na2CO3 = 2 but decreased when Na2CO3 = 4. On the other hand, when the ratio of peat to Na2CO3 was fixed at 1/2 and the proportion of urea was varied in the range of 0.5–3, the surface area markedly increased up to urea = 1; however, a significant increase did not take place thereafter, even when the proportion of urea was increased. According to these results, the optimum mixing ratio of peat/urea/Na2CO3 and heat treatment conditions to produce high-surface-area activated carbon from peat may be 1/1–3/2 and holding at 800–900 °C for 0–1 h, respectively.

    更新日期:2018-03-24
  • Simultaneous extraction of oil and tea saponin from Camellia oleifera Abel. seeds under subcritical water conditions
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-20
    Hong Wu, Changzhu Li, Zhenmei Li, Rukuan Liu, Aihua Zhang, Zhihong Xiao, Li Ma, Jilie Li, Shuguang Deng
    更新日期:2018-03-22
  • Effect of HCl and CO on sulfur trioxide formation mechanisms during oxy-fuel combustion
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-20
    Junzhe Guo, Xiaowei Liu, Hao Wang, Penghui Zhang, Yishu Xu, Zhenguo Chen, Minghou Xu

    The concentration of SOX, HCl, CO, NOX etc. in the flue gas during oxy-fuel combustion is all relatively higher compared with air combustion. Higher SO3 concentration increases the risk of low-temperature corrosion. The higher concentration of HCl and CO can also cause corrosion, and they may play roles on SO3 formation. Thus homogeneous experiment and pulverized coal experiment were done on different furnace system to clarify the effects of HCl and CO on SO3 formation during oxy-fuel combustion. Different inlet concentration of HCl, CO, SO2, H2O, O2 and CO2 were used to simulate the flue gas of the combustion. The results indicated that HCl inhibited SO3 formation but CO promoted SO3 formation at the experimental temperature. HCl richens the radical pool and might generate HO2 radical which was negative to SO3 formation. CO could react with O2 to generate more O radical which was vital to SO3 formation and consume HO2 radical when steam existed. The pulverized coal experiment presented a different SO3 concentration at the same input sulfur and steam level, meaning the fly ash and other gas phase components in the flue gas could also influence SO3 formation.

    更新日期:2018-03-22
  • Wood washing: Influence on gaseous and particulate emissions during wood combustion in a domestic pellet stove
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-20
    Guillaume Schmidt, Gwenaëlle Trouvé, Gontrand Leyssens, Cornelius Schönnenbeck, Paul Genevray, Fabrice Cazier, Dorothée Dewaele, Coralie Vandenbilcke, Elodie Faivre, Yann Denance, Céline Le Dreff-Lorimier

    Nowadays, the use of biomass increasingly replaces the fossil fuels for the domestic heating production. In order to reduce pollutant emissions from biomass combustion, wood was washed at room temperature in order to represent natural rain leaching before burning in a recent pellet stove (2010s) of nominal output of 6.3 kW. Raw and washed woods were combusted for three different types of wood (oak, beech and fir) and the study focused on their particulate and gaseous emissions (Total Suspended Particles (TSP), Particulate Matter with diameter below 2.5 μm (PM2.5), carbon monoxide (CO), nitrogen oxides (NOx) and Total Volatile Organic Compounds (TVOC)). Polycyclic Aromatic Hydrocarbons (PAH), aldehydes and wood tracers as phenols compounds were also measured. In addition, considering the toxic equivalent factor, the human health impact of adsorbed and gaseous PAH is considerably reduced (96%) in the case of washed fir combustion. Emission factors of CO and TSP for washed wood combustion also show a decrease up to 50% depending on the type of wood used. Furthermore, phenolic compounds, Benzene, Toluene, Ethylbenzene, Xylenes and Trimethylbenzene (BTEXT) emissions can also be reduced by the washing of biomass. Washed oak combustion leads to a clear decrease by 60% of the total of BTEXT. In the case of phenols emissions, phenol shows a significant decrease by 91% during the combustion of washed fir wood.

    更新日期:2018-03-22
  • Extension of Kelvin equation to CO2 adsorption in activated carbon
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-20
    Guojun Yin, Qingya Liu, Zhenyu Liu, Weize Wu
    更新日期:2018-03-22
  • Investigation on solubility of multicomponents from semi-anthracite coal and its effect on coal structure by Fourier transform infrared spectroscopy and X-ray diffraction
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-20
    Xiaodong Zhang, Shuo Zhang, Pengpeng Li, Zhe Ding, Zongchao Hao

    As a sedimentary rock composed of organic carbonaceous matters with different molecular sizes and inorganic minerals, coal can be extracted by organic solvents and dissolved by acids to make chemical compositions and structures changed, thus influencing on the occurrence and migration of coalbed methane (CBM). For the purpose of investigating the impacts of different solvents on coal structure, semi-anthracite coal samples from Huoerxinhe coalmine in the central part of Qinshui Basin were treated by four single solvents (tetrahydrofuran (THF), carbon disulfide (CS2), hydrochloric acid (HCl) and chlorine dioxide (ClO2)), and by combined solvents (an organic solvent and an inorganic solvent with different treatment orders). Then the solubility behaviors of the organic compounds or inorganic matters from coal were investigated and the changes of the functional groups and the microcrystalline structure in coal were addressed using Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD). The results show the extraction yields of organic solvents are significantly greater than the dissolution yields of inorganic solvents, and the solubility of HCl is relatively higher than that of ClO2. Specifically, main functional groups in coal, including aliphatic, aromatic and oxygen-containing functional groups, have a decline tendency to different degrees under the treatment of organic solvents. Further, main microcrystalline structure parameters increase in vertical direction but reduce in parallel direction of the aromatic carbon network layer with the swelling effect, regardless of an organic solvent or inorganic solvent treatment. Only by the organic solvent treatment, do the d002 values of the basic structure unit of coal appear dramatically enlarged characteristics. Whereas, main functional groups and microcrystalline structure in coal show relatively complex features within the combined solvents treatment because of the phenomenon of pore-blockade, pore-expansion or slight solvent retention. Based on the change characteristics and mechanisms, the chemical structure model of semi-anthracite coal is put forward for providing a reference for the further study of coal structure.

    更新日期:2018-03-22
  • The function of poly aromatic nuclei structure for adsorption of vanadyl/nickel etioporphyrin on asphaltene/graphene
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-20
    Feifei Chen, Qiushi Zhu, Shuofan Li, Zhiming Xu, Xuewen Sun, Suoqi Zhao

    Adsorption behaviors of metal porphyrins on graphene were studied by investigating adsorption kinetics, thermodynamics and density functional theoretical calculation. The interactions between poly aromatic nuclei structure of graphene and metal porphyrins were confirmed by XPS, TEM analysis and adsorption results, which account for adsorption of metal porphyrins. As the poly aromatic nuclei structure is the main structure of asphaltene, it also acted as active sites for adsorption of metal porphyrins. The differences of adsorption results between graphene and asphaltene indicated that the aliphatic side chains and other structures of asphaltene also have influence on adsorption process. Furthermore, chemical and physical adsorptions were also confirmed during the adsorption process of porphyrins on graphene.

    更新日期:2018-03-22
  • The catalytic reforming of tar from pyrolysis and gasification of brown coal: Effects of parental carbon materials on the performance of char catalysts
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-20
    Shu Zhang, Zongding Chen, Haiyong Zhang, Yonggang Wang, Xiuqiang Xu, Liang Cheng, Yuming Zhang

    The carbon structure of char as catalysts is very crucial as it greatly governs the catalytic activity of char for tar reforming reactions. More importantly, the char structure also plays an important role in affecting the interactions between the inherent metal species and carbon atoms, thus affecting the catalytic performances. This study aims to investigate the effects of char structure on the reforming of tar derived from the gasification and pyrolysis of Shengli brown coal. Chars prepared from five kinds of acid-washed carbonaceous materials, including biomass, brown coal, bituminous coal, anthracite and graphite, were used as tar reforming catalysts in this work. The different effectiveness of H-form char catalysts from the different ranking carbon materials have clearly shed light on the effects of char structure on tar reforming. Results show that the chars from biomass and low rank coals featured obviously higher catalytic activity than those from high rank fuels. The variation in char structure that was revealed by FT-Raman has greatly exerted impacts on tar yields as well as tar compositions. Interestingly, the supply of steam (in the gasification condition) did not always see the reduction in tar yields, very much depending on the type of char catalysts used in the experiments.

    更新日期:2018-03-22
  • Direct synthesis of dimethyl ether in multi-tubular fixed-bed reactors: 2D multi-scale modelling and optimum design
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-20
    Raquel Peláez, Pablo Marín, Fernando V. Díez, Salvador Ordóñez

    The scope of this work is to explore the viability of the direct synthesis of dimethyl ether (DME) over bifunctional catalysts, such as mixtures of CuO/ZnO/Al2O3 and γ-Al2O3 at industrial scale. To accomplish this purpose, the process is simulated using a phenomenological mathematical model considering momentum, mass and energy balances, applied to both the catalyst particles and reactor bed, which is solved in 2D axisymmetric coordinates. This constitutes a step beyond most of the available studies for the modelling of the DME synthesis reaction, based on simple 1D isothermal models. The use of this detailed model revealed the importance of intraparticle mass and heat transfer, with effectiveness factors within the range 0.5–1.1. At the reactor scale, radial phenomena were found to be relevant. A design-sensitivity analysis of mass flux, catalyst fraction, pressure, feed temperature, cooling potential and tube diameter on the reactor performance was carried out. An optimized reactor design that provides 80% CO conversion operating at inlet temperature and pressure 245 °C and 40 bar, corresponds to 0.02 m diameter, 8.50 m length and 3600 h−1 gas-hourly space velocity with a yield of dimethyl ether of 0.53.

    更新日期:2018-03-22
  • Experimental study on NO emissions from pulverized char under MILD combustion in an O2/CO2 atmosphere preheated by a circulating fluidized bed
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-19
    Qing-Gang Lyu, Shu-Jun Zhu, Jian-Guo Zhu, Hui-Xing Wu, Yan-Qi Fan

    This study examined the combustion of pulverized char under an O2/CO2 atmosphere to (1) attempt to achieve a moderate or intense low-oxygen dilution (MILD) combustion process and (2) investigate the effects of gas distribution modes on NO emissions. First, fuel was preheated in a circulating fluidized bed (CFB) and then high-temperature preheated fuel from the CFB was burned in a down-fired combustor (DFC). The study was conducted with two secondary gas nozzle positions, three tertiary gas position arrangements, and four secondary oxygen ratios in the DFC. During the test process, the combustion temperature was uniform in the CFB and the CO2 concentration in the flue gas reached approximately 90%. MILD combustion was achieved when the secondary gas nozzle position was center and the char combustion reaction dispersed into the upper low-oxygen space in the DFC. The obvious flame front disappeared and the temperature profile in the DFC was more uniform which is also one of the important features of MILD combustion. This reduced NO emissions by around half while maintaining high combustion efficiency. NO emissions were further reduced by a particular arrangement of tertiary gas positions, but at the cost of reducing combustion efficiency.

    更新日期:2018-03-20
  • Prediction of hydrocarbon yield from wet Botryococcus braunii: The influences of colony surface charge and diameter on the amount of extractable hydrocarbon
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-19
    Shun Tsutsumi, Yasuhiro Saito, Yohsuke Matsushita, Hideyuki Aoki

    A colonial microalga, Botryococcus braunii synthesizes extracellular polysaccharides (EPS) forming a sheath around its colonies, which limits the extraction of hydrocarbons from this microalga. As thermal or mechanical pretreatment of B. braunii improves the hydrocarbon yield, the EPS removal and degree of algal colony disruption before and after pretreatment were evaluated using zeta potential and particle size distribution (PSD) to predict hydrocarbon yield from the alga. Since zeta potential can evaluate the ionizable state of particles, the zeta potential of B. braunii would be able to evaluate the removal degree of EPS and this feature had the potential to determine hydrocarbon yield quickly. The zeta potential of algal samples without pretreatment was −30.5 mV at pH 9, whereas that with pretreatment ranged from −29.7 to −18.8 mV. The elevation of zeta potential and EPS removal had a linear relationship (R-squared value = 0.96). The hydrocarbon yields exponentially increased in proportion to the degree of colony disruption after mechanical treatments (R-squared value = 0.81). These findings suggest that the zeta potential and PSD of B. braunii may be used as indicators for EPS removal and hydrocarbon yield.

    更新日期:2018-03-20
  • Condensational growth assisted Venturi scrubber for soot particles emissions control
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-19
    Francesco Di Natale, Francesco La Motta, Claudia Carotenuto, Marco Tammaro, Amedeo Lancia

    This paper aims to evaluate how condensational growth may be used to improve the performances of a Venturi scrubber in removing soot particles, which are among the most relevant air pollutants emitted in industrial and power plants exhaust gases. Former studies on this system, called Condensational Growth assisted Venturi scrubbers (CGVS), suggested that the most relevant step to address their efficiency is the assessment of the amount of water that condense on the soot particles, which determines the actual aerosol size distribution entering the Venturi. Unfortunately, a definite physical mathematical model to predict the actual condensational growth of an ensemble of non-spherical particles is not yet available and experimental investigation is better suited to assess this point. This study reports experimental data on the size distribution achieved by exposing model soot particles to a water supersaturated gas for different residence times. The obtained size distributions are used to estimate the efficiency of a Venturi scrubber in removing the water-soot aerosols, allowing a comparison with the removal of parent soot particles. The experiments were carried out at lab scale by using a laminar-flow growth tube, a simple device to perform a controlled condensational growth. The experiments indicated that, even for a hydrophobic material as soot, condensational growth is effective even at supersaturation levels as low as 1.02. Liquid-solid aerosols from nearly 2 to >3 times larger than the parent particles are produced with a supersaturation level lower than 1.15. Finally, the analysis of experimental data indicated that the fraction of particles subjected to condensational growth is relevant. Indeed, calling as ψ the fraction of particles that become larger than the 98% percentile of the original particle size distribution, we found that ψ can be as high as 78%. The analysis of data indicated that an appreciable linear correlation exits among ψ and the 95th percentile of the supersaturation level, S95, while not being dependent on the exposure time. The experimental evidences suggest that the adsorption of water molecules over the soot surface overcome the effects of hydrophobicity and of line tension effects, favouring condensation of water over the soot surface and leading to a higher nucleation rate even at low supersaturation. Application of the Venturi scrubber model to the water-soot aerosol leaving the growth tube indicate that the CGVS may remove particles with an efficiency far higher than that achieved by the stand alone Venturi. For a given Venturi's throat length and velocity and a given liquid-to-gas ratio, the CGVS efficiency depends almost linearly on ψ and, in turns on S95. Experimental and model results suggested that the CGVS can be a valuable and effective device to capture soot particles and that condensational growth can be used as a retrofit method for existing units.

    更新日期:2018-03-20
  • Low energy cost conversion of methane to ethylene in a hybrid plasma-catalytic reactor system
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-17
    Evangelos Delikonstantis, Marco Scapinello, Georgios D. Stefanidis
    更新日期:2018-03-19
  • Investigation of strength and reduction reactivity during heat treatment in simulated-experimental blast furnace of carbon-containing pellet prepared by vapor deposition of tar to cold-bonded pellet with large particle size
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-16
    Yuuki Mochizuki, Naoto Tsubouchi, Tomohiro Akiyama

    Optimum conditions for preparing carbon-containing pellets with a high crushing strength and high reactivity using three kinds of cold-bonded pellets (CPs) prepared by different methods are investigated in this study. The carbon-containing pellets, which have a size fraction suitable for blast furnace are prepared by completely filling the pores in CPs with carbonaceous materials derived from coke oven gas (COG) tar by the vapor deposition (VD) method. A flow-type quartz fixed-bed reactor is used for this method, using a combination of tar pyrolysis at 700 °C and VD at 350 °C. The changing pore size distribution, distribution of the carbonaceous material, and crushing strength of the VD samples are then measured for the prepared composites. The carbonaceous materials derived from COG tar completely fills into the mesopores and macropores of the CPs, which is prepared by using Portland cement (PCB) or Carboxymethyl cellulose (CMC), as the binder, and the aging method in stainless-steel container, with increasing VD treatment time. When PCB is treated by the VD method, the C content and crushing strength tends to increase with increasing VD treatment time, and reached 16 wt%-dry and 45 daN, respectively, until 60 min; these values are comparable to the strength of metallurgical-coke with DI1506 = 87.1. Additionally, carbonaceous materials are uniformly deposited in the particles inside. The changes in the reduction behavior and crushing strength of the prepared VD sample under various heat conditions (simulation-values in experimental-blast furnaces in COURSE50 project). The reduction extent of the VD samples prepared from PCB reaches up to 30–40% at 850 °C. These rates increase above 850 °C and attain a value >95% until 950 °C irrespective of the heating and atmospheric conditions. Fe2O3 and Fe3O4 in the VD samples are reduced to FeO and/or α-Fe until 850 °C under any condition used, while FeO is completely reduced to α-Fe by 950 °C. The cold crushing strength of VD samples is maintained up to 850 °C. Although this value drastically decreases at 900 °C, which is the temperature at which α-Fe formation occurred, there is no decrease in strength for the reduction of Fe2O3 to Fe3O4, which has been observed reduction disintegration occurs in a conventional blast furnace.

    更新日期:2018-03-18
  • From orchids to biodiesel: Coco coir as an effective drywash material for biodiesel fuel
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-13
    Lisa S. Ott, Meghan M. Riddell, Elizabeth L. O'Neill, Genessee S. Carini
    更新日期:2018-03-15
  • Carbon nanotubes formation and its influence on steam reforming of toluene over Ni/Al2O3 catalysts: Roles of catalyst supports
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-13
    Limo He, Song Hu, Long Jiang, Guang Liao, Xiaofang Chen, Hengda Han, Lingfeng Xiao, Qiangqiang Ren, Yi Wang, Sheng Su, Jun Xiang

    The effects of catalyst supports (γ-Al2O3 and α-Al2O3) on hydrogen yield and carbon nanotubes formation were studied during steam reforming of toluene over Ni-based catalysts. Hydrogen yield and CNTs quality over Ni/γ-Al2O3 were better than those over Ni/α-Al2O3 at S/C ratio of 1 due to the high Ni dispersion of Ni/γ-Al2O3. With the increasing of steam addition, CNTs production remarkably increased over Ni/α-Al2O3, while it decreased over Ni/γ-Al2O3. The CNTs on Ni/γ-Al2O3 were corroded at S/C ratio of 3 by excess steam. Toluene conversion and hydrogen yield over Ni/α-Al2O3 were significantly larger than those over Ni/γ-Al2O3, which was attributed to the different effects of CNTs on catalytic activity. The strong interaction between Ni particle and γ-Al2O3 led to the base-growth mechanism of CNTs on Ni/γ-Al2O3 in which Ni particles located at the bottom of CNTs, thus the growth of CNTs covered Ni active sites and decreased catalytic activity of Ni/γ-Al2O3. By contrast, owing to weak interaction, CNTs grown on Ni/α-Al2O3 followed tip-growth mechanism that would increase Ni dispersion and promote reforming reaction.

    更新日期:2018-03-15
  • Fast pyrolysis and combustion characteristic of three different brown coals
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-13
    Jun Han, Li Zhang, Hee Joon Kim, Yuichi Kasadani, Liuyun Li, Tadaaki Shimizu

    In this study, brown coals fast pyrolysis/combustion was carried out in a moving furnace coupled with a balance, and the mass change of sample and emission of hydrocarbon components were online recorded. On the basis of the experimental results, the pyrolysis/combustion kinetic parameters were calculated. In the fast pyrolysis process, the apparent activation energy of Loy Yang brown coal, Wara brown coal and Usibelli brown coal was 36.9, 33.1 and 28.1 kJ/mol respectively, which was far lower than that obtained under the slow pyrolysis process. The main light hydrocarbon gases evolved from brow coal fast pyrolysis were CH4, C2H6 and C3H8. At the same time, it was found that the reaction rate of brown coal fast pyrolysis was strongly influenced by the oxygen content of the raw coal. The high oxygen content of the raw coal was beneficial to pyrolytic reaction. The combustion process of the brown coal could be divided two stages: in the first stage, the evolution and combustion of volatile matter occurred simultaneously. In the secondary stage, only char combustion occurred. The apparent activation energy of char combustion was 2.3–20.8 kJ/mol.

    更新日期:2018-03-15
  • Microwave assisted co-pyrolysis of biomasses with polypropylene and polystyrene for high quality bio-oil production
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-12
    Dadi V. Suriapparao, Bhanupriya Boruah, Dharavath Raja, R. Vinu
    更新日期:2018-03-13
  • Chemical agglomeration properties of fine particles immersed in solutions and the reduction in fine particle emission by adding emulsion polymers
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-08
    Lei Zhou, Shu-ying Yang, Wu Chen, Xiao-bei Wang, Zhu-lin Yuan, Lin-jun Yang, Hao Wu

    To reduce the fine particle concentration in coal-fired flue gas, an emulsion agglomeration agent with excellent atomization performance and low viscosity was applied in a chemical agglomeration experiment. The chemical agglomeration properties of an emulsion polymer and a water-soluble polymer on fine particles were compared and investigated experimentally in this study. In addition, the relationship between the mass concentration and solution viscosity was explored, and the atomization performances of a two-fluid nozzle were also studied. The results showed that when the mass concentration of the agglomeration agent increased, the fly ash particles in the solution became larger; moreover, the final agglomerate diameter and the solution viscosity were related to the polymer molecular weight. According to the phase Doppler anemometry (PDA) experimental results, the median diameter (D50) of the agglomeration solution droplets increased as the mass concentration increased, and the atomization property of the emulsion polymer solution was evidently superior to that of the water-soluble polymer solution. In the experimental facility, chemical agglomeration experiments using four kinds of agglomeration agent were carried out, and they proved that the removal efficiency of fine particles was inversely proportional to the median diameter of the atomized solution droplets. Emulsion polymers can greatly enlarge fine particles and reduce the concentration of the fine particles. The removal efficiency of number concentration was improved by 20–25%.

    更新日期:2018-03-11
  • Initial stage of deposit formation process in a coal fired grate-rotary kiln for iron ore pellet production
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-09
    Shuai Wang, Yufeng Guo, Jianjun Fan, Yu He, Tao Jiang, Feng Chen, Fuqiang Zheng, Lingzhi Yang
    更新日期:2018-03-11
  • Wrinkled porous carbon nanosheets from methylnaphthalene oil for high-performance supercapacitors
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-07
    Hanfang Zhang, Xiaojun He, Jing Gu, Yuanyang Xie, Hengfu Shui, Xiaoyong Zhang, Nan Xiao, Jieshan Qiu
    更新日期:2018-03-08
  • Upgrading of bio-oil from catalytic pyrolysis of pretreated rice husk over Fe-modified ZSM-5 zeolite catalyst
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-07
    Shuping Zhang, Houlei Zhang, Xinzhi Liu, Shuguang Zhu, Linlin Hu, Qiong Zhang

    Catalytic pyrolysis of rice husk sample after combined washing-torrefaction pretreatment over Fe-modified ZSM-5 zeolite catalyst for bio-oil upgrading was investigated. This study shows the effects of Fe-modified ZSM-5 zeolite catalyst with different Fe loading and different pretreatment conditions from an integrated process of pretreatment and catalytic pyrolysis to improve the quality of bio-oil. The results indicated that with the increase of Fe loading, the yield of upgraded bio-oil decreased, while the relative content of hydrocarbons was enhanced obviously. The optimum Fe-modified ZSM-5 zeolite catalyst should be 4%Fe/ZSM-5 because excessive loading of Fe could affect the yield of upgraded bio-oil. Furthermore, it was found that during catalytic pyrolysis process with 4%Fe/ZSM-5, combined washing-torrefaction pretreatment had an obvious effect on promoting the production of hydrocarbons and further increasing the selectivity for BTX (benzene, toluene and xylenes), while severe torrefaction condition could significantly decrease the yield of upgraded bio-oil. Generally, combined washing-torrefaction pretreatment at mild torrefaction condition (210 and 240 °C in this study) was more suitable for upgrading of bio-oil from catalytic pyrolysis over Fe-modified ZSM-5 zeolite catalyst.

    更新日期:2018-03-08
  • Preliminary understanding on the ash behavior of algae during co-gasification in an entrained flow reactor
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-07
    Youjian Zhu, Philip J. van Eyk, Christoffer Boman, Markus Broström, Kawnish Kirtania, Patrycja Piotrowska, Dan Bostrom, Rocky de Nys, Sankar Bhattacharya, Francesco G. Gentili, Peter J. Ashman

    Algae are considered as a promising alternative fuel to produce energy due to its advantages such as high production yield, short growth cycle and flexible growing environment. Unfortunately, ash-related issues restrict its thermochemical utilization due to the high ash content and especially the high alkali metal concentration. In this paper, the gasification performance and ash behavior were experimentally analysed for three macro- and micro-algal species. Clear differences in the proximate and ultimate compositions were found between the cultivated algae used in this study and macroalgae (seaweed) harvested from the marine environments. Algal biomass generally contained higher Na and P contents than lignocellulosic biomass. Microalgae also had a relatively high mineral content due to the impurities in the harvesting process which included centrifugal pumping followed by sedimentation. Co-gasification of 20 wt% algae with softwood was investigated using an entrained flow reactor. The addition of both macroalgal species Derbersia tenuissima and Oedogonium to softwood had a limited influence on the gas yields and carbon conversion. On the other hand, the addition of the microalgal species Scenedesmus significantly decreased the main gas yields and carbon conversion. Moreover, the addition of algae clearly changed the residual ash composition of the base fuel. Finally, a preliminary understanding of the ash behavior of the tested algae blends was obtained through the analysis of the fuel ashes and the collected residual ashes. Fouling and corrosion were presumably occurred during the co-gasification of wood/macroalgae blends in view of the high alkali metal content. Microalga Scenedesmus had a high mineral content which could potentially capture the alkali metal in the ash and mitigate fouling when gasified with softwood. The growing environment and harvesting method were found to be significantly affecting the ash behavior implying the need for careful consideration regarding co-gasification process.

    更新日期:2018-03-08
  • Ash and slag properties for co-gasification of sewage sludge and coal: An experimentally validated modeling approach
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-03-06
    Daniel Schwitalla, Markus Reinmöller, Clemens Forman, Christian Wolfersdorf, Matthias Gootz, Jin Bai, Stefan Guhl, Markus Neuroth, Bernd Meyer

    Regulatory changes in the EU and Germany, and environmental aspects direct the attention of the agricultural and energy sector towards sewage sludge as a new resource. The present study evaluates the co-gasification of sewage sludge with brown coal in a slagging gasifier. Currently, a lack of experimental data on phosphorous containing ashes and slags under reducing atmospheres limits our understanding of gasification of this fuel. To address this gap, in this study the ash and slag properties of one brown coal and its mixtures with sewage sludge were experimentally investigated under a reducing atmosphere and predicted with FactSage™. An ASPENplus™ simulation of the co-gasification is conducted to evaluate the impact of the changing feedstock characteristics on major process parameters when different mixtures of sewage sludge and brown coal are fed into a Siemens gasifier. The flow temperature of the coal ash can noticeably be reduced if the sewage sludge ash content is increased up to 50 wt%. Thermochemical calculations using FactSage™ are in good agreement with the experimental ash fusion behavior. This paper describes a method to improve the calculation to better fit the experimental values. The elemental liberation of the main ash components are modeled using FactSage™ and experimentally validated. Except for potassium, no significant release into the gas phase was detected in the experiment. This is in contrast to the predicted evaporation of phosphorous. The addition of sewage sludge results in a lower viscosity of the slags of the mixtures in this study. As a result, the studied entrained-flow gasifier can be operated at lower temperatures while staying at an optimal viscosity for slag tapping. On the other hand, it decreases the temperature working range inside a slagging gasifier, where the slag viscosity lies between 2 and 25 Pa s. The resulting implications on the process parameters of entrained flow gasification have been modeled with ASPENplus™. Even low sewage sludge additions to the brown coal allow for lower gasifier temperatures, decreasing the specific oxygen consumption. Moreover, the cold gas efficiency and the H2/CO ratio are increased.

    更新日期:2018-03-07
  • Some characteristics of the self-heating of the large scale storage of biomass
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-02-22
    J.M. Ashman, J.M. Jones, A. Williams

    Increasingly large quantities of biomass are being transported and stored for use in bioenergy applications. This large storage of biomass is liable to undergo self-heating sometimes leading to ignition and fire. Numerous studies on both the laboratory scale and by using theoretical analyses have been made in order to predict their behaviour but these are made on the basis of a number of simplifying assumptions. It is clear from studies reported here of self-heating in 40 kt storage piles of wood pellets that the process is much more complex than the simpler models suggest since thermal waves are observed.

    更新日期:2018-02-23
  • Improving the removal of fine particulate matter based on heterogeneous condensation in desulfurized flue gas
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-02-22
    Rui Zhang, Hao Wu, Xiaodong Si, Lingling Zhao, Linjun Yang

    To reduce the emission of fine particulate matter (PM) in coal-fired power plants, a new method aimed to improve the removal of fine particulate matter based on heterogeneous vapor condensation was investigated. The ideal supersaturation environment, necessary to the occurrence of heterogeneous vapor condensation, was achieved by reducing the initial temperature of limestone-gypsum desulfurization flue gas with a fluorine plastic heat exchanger. The temperature drop, initial relative humidity and initial temperature of desulfurized flue gas have an important influence on the establishment of ideal supersaturation environment and the reduction efficiency of fine particulate matter. Numerical calculation indicates that a higher temperature drop and initial relative humidity of the desulfurized flue gas is beneficial to the establishment of ideal supersaturation environment, while the influence of initial temperature of desulfurized flue gas is unobvious. It has been also experimentally proved that the increase of temperature drop and initial relative humidity have a positive effect to the improvement of the reduction efficiency. However, it can be also found that the reduction efficiency changes slightly with the variation of the initial temperature of desulfurized flue gas. Therefore, this method is suitable for different initial temperatures of desulfurized flue gas and is more applicable for practical industrial applications. Most commonly, the optimal value of temperature drop of desulfurized flue gas is in the range of 4 to 6 °C and the corresponding number concentration of fine particulate matter emission can be reduced as high as about 43%.

    更新日期:2018-02-23
  • The ignition dynamics of the water-filled fuel compositions
    Fuel Process. Technol. (IF 3.752) Pub Date : 2018-02-22
    Roman I. Egorov, Dmitry V. Antonov, Timur R. Valiullin, Pavel A. Strizhak
    更新日期:2018-02-23
  • 更新日期:2018-02-23
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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