Alicia Callejas

@article{Esarte2011a,

title = {Influence of the concentration of ethanol and the interaction of compounds in the pyrolysis of acetylene and ethanol mixtures},

author = {Claudia Esarte and Alicia Callejas and Ángela Millera and Rafael Bilbao and María U Alzueta},

doi = {10.1016/j.fuel.2010.09.051},

issn = {00162361},

year  = {2011},

date = {2011-02-01},

journal = {Fuel},

volume = {90},

number = {2},

pages = {844--849},

publisher = {Elsevier},

abstract = {The pyrolysis of acetylene, ethanol and acetylene-ethanol mixtures in the 975-1475 K temperature range has been studied. The purpose of this work is to analyze the variation of soot and gas products coming from the pyrolysis of acetylene when adding increasing amounts of ethanol. Gas and soot products coming from the pyrolysis of 30,000 ppm of acetylene and different concentrations of ethanol (0-20,000 ppm) have been identified and quantified, and the influence of the amount of ethanol added has been analyzed. Analyses are supported on model calculations run with Chemkin using a detailed gas phase chemical kinetic mechanism, including subsets for acetylene and ethanol reactions and PAH formation and consumption reactions. In addition, the sum of the soot obtained from the individual pyrolysis of acetylene and ethanol is compared with the results coming from the pyrolysis of the corresponding acetylene-ethanol mixtures in order to analyze the interaction when they react jointly. Experimental results highlight the importance of the relative concentration acetylene/ethanol in the mixtures. Moreover, the results show that adding very small concentrations of ethanol, i.e. up to 600 times lower than acetylene concentration, leads to a diminution on the production of soot from the pyrolysis of acetylene. textcopyright 2010 Elsevier Ltd. All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Alzueta2008,

title = {An experimental and modeling study of the oxidation of acetylene in a flow reactor},

author = {María U Alzueta and M Borruey and Alicia Callejas and Ángela Millera and Rafael Bilbao},

doi = {10.1016/j.combustflame.2007.10.011},

issn = {00102180},

year  = {2008},

date = {2008-02-01},

journal = {Combustion and Flame},

volume = {152},

number = {3},

pages = {377--386},

publisher = {Elsevier},

abstract = {Acetylene is a hydrocarbon of significance in a variety of processes. It is an intermediate species during combustion processes and it is recognized as one of the most important soot precursors. Despite the large number of studies carried out in the past decades in relation to acetylene conversion in a variety of reactors (shock tubes, flames, and jet-stirred reactors) and operating conditions (from rich to lean environments, at different temperatures and pressures), the conversion of acetylene is not yet well described. An experimental and theoretical study of the oxidation of acetylene at atmospheric pressure in the temperature range 700-1500 K, and from fuel-rich to significantly fuel-lean conditions, has been performed. The experiments were conducted in an isothermal quartz flow reactor and the influence of the temperature and stoichiometry (by varying the O2 concentration for a given C2H2 initial level) on the concentrations of C2H2, CO, and CO2 has been analyzed. A reaction mechanism based on the model of Glarborg et al. [Combust. Flame 115 (1998) 1-27] for hydrocarbon/NO interactions, updated by Glarborg et al. [Combust. Flame 132 (2003) 629-638], and the model of Skjøth-Rasmussen et al. [Proc. Combust. Inst. 29 (2002) 1329-1336] for benzene formation, using methane as the initial hydrocarbon, has been used for calculations. The results show the oxidation regime of acetylene for different air excess conditions and the model developed allows a fairly good description of the experiments made. The experimental results are analyzed in terms of detailed chemistry and the main issues are discussed. The model here used should be further included in more detailed kinetic schemes and models developed to describe not only hydrocarbon conversion but also soot formation. textcopyright 2007 The Combustion Institute.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ruiz2007a,

title = {Reactivity towards O2 and NO of the soot formed from ethylene pyrolysis at different temperatures},

author = {Pilar M Ruiz and Alicia Callejas and Ángela Millera and María U Alzueta and Rafael Bilbao},

url = {https://www.degruyter.com/view/journals/ijcre/5/1/article-ijcre.2007.5.1.1478.xml.xml},

doi = {10.2202/1542-6580.1478},

issn = {15426580},

year  = {2007},

date = {2007-09-01},

journal = {International Journal of Chemical Reactor Engineering},

volume = {5},

number = {1},

publisher = {Walter de Gruyter GmbH},

abstract = {The influence of temperature on the formation of soot from ethylene pyrolysis has been studied. Pyrolysis experiments were carried out in a quartz reactor in the 1000-1200°C temperature range, for an inlet C 2H4 concentration of 50000 ppmv and a gas residence time of 4552/T(K) seconds. Outlet gases were analyzed by gas chromatography and the amount of soot produced measured. The reactivity of the soot samples obtained towards O2 and NO was also studied. Results show that the higher the formation temperature, the less reactive the soot. The soot samples were further characterized using elemental analysis, scanning electron microscopy and Raman spectroscopy, in order to study their structural properties, and relate them to their reactivity. Additionally, a comparison of the reactivity towards NO between acetylene and ethylene soot samples obtained under similar conditions has been carried out. The soot samples obtained from ethylene pyrolysis present higher reactivity towards NO than the soot samples formed from acetylene. Copyright textcopyright 2007 The Berkeley Electronic Press. All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}

@article{Ruiz2007d,

title = {Soot formation from C2H2 and C2H4 pyrolysis at different temperatures},

author = {Pilar M Ruiz and Alicia Callejas and Ángela Millera and María U Alzueta and Rafael Bilbao},

doi = {10.1016/j.jaap.2006.10.012},

issn = {01652370},

year  = {2007},

date = {2007-05-01},

journal = {Journal of Analytical and Applied Pyrolysis},

volume = {79},

number = {1-2 SPEC. ISS.},

pages = {244--251},

publisher = {Elsevier},

abstract = {A study of the pyrolysis of two hydrocarbons, C2H2 and C2H4, at different temperatures has been carried out in order to compare their behaviour in terms of soot and gas yields and gas composition. Pyrolysis experiments have been performed in the same conditions for both hydrocarbons: an inlet hydrocarbon concentration of 15,000 ppmv and a temperature range of 1000-1200 °C. For C2H2 and C2H4 pyrolysis tests, the results present the same trend when increasing the temperature: an increase in soot yield, a decrease in gas yield and a similar evolution of the outlet gases. Comparatively, it can be observed that acetylene is a more sooting hydrocarbon than ethylene for a given temperature. Additionally, the study of soot reactivity with O2 and NO shows that the soot samples obtained from ethylene show a slightly higher reactivity towards O2 and NO than the soot samples formed from acetylene. textcopyright 2006 Elsevier B.V. All rights reserved.},

keywords = {},

pubstate = {published},

tppubtype = {article}

}