827 research outputs found
Interactions of CO, HCl, and Sox in Pulverised Coal Flames
No full textThe effect of HCl and SO_2 on CO oxidation in pulverised coal flames was investigated experimentally and kinetically in an entrained flow combustion reactor. Two bituminous coals (German 'Goettelborn' and a Polish coal) were used as fuels with a feeding rate of 1 or 1.5 kg/h. HCl or SO_2 is introduced into the reactor premixed with the primary air. Experimental results indicate that HCl addition may inhibit CO oxidation in coal flames and increases CO emission. Reducing temperature in the reactor will enhance the inhibitory effect of HCl on CO oxidation. The measured CO profiles along the reactor height clearly show that the addition of HCl may inhibit CO oxidation. In the experimental range of SO_2 addition. The inhibiting effect of SO_2 on CO oxidation is less significant than HCl. A detailed kinetic mechanism is used to model the reactions. And the controlling reactions are analysed
Experimental investigation and numerical simulation of CO oxidation with HCl addition
No full textChlorine is rich in biomass and some coals and significantly released as HCl(g) during combustion process, and this promotes the recombination of free radicals OH, H, O, and HO2 and further influences CO oxidation. In this paper, the inhibition effect of HCl on CO oxidation is investigated by experiment and numerical simulation. The experiment is operated under different reaction zone temperatures and equivalence ratios in an entrained flow reactor. And the numerical simulation is conducted by CFD software coupled with reduced reaction mechanism. The results indicate that HCl addition obviously inhibits CO oxidation under oxygen-rich condition, and the inhibition enhances as HCl concentration rises, but weakens as temperature increases. Under chemical equivalent and oxygen-lean conditions, the inhibition effect is limited. (C) 2016 Elsevier Ltd. All rights reserved
Effect of H<sub>2</sub>S and HCl contaminants on nickel and ceria pattern anode solid oxide fuel cells
No full textIn this study, with the motivation of elucidating the effect of H2S and HCl on solid oxide fuel cell anodes, nickel and ceria pattern anodes are prepared on yttrium-stabilized zirconia electrolyte, and the effect of H2S and HCl on their performance is tested using electrochemical impedance spectroscopy. However, it has been found that while H2S adversely impacts both nickel and ceria, the poisoning caused is reversible for nickel and only partially reversible for ceria. Poisoning kinetics are similar and fast for both materials, while recovery kinetics are slower for ceria than nickel. High sulfur coverage is the rate-limiting factor inferred from the elementary kinetic modeling. Unlike H2S, the presence of HCl appeared to be favorable for electrochemical oxidation as the polarization resistance of both pattern electrode cells decreased upon feeding HCl contaminated hydrogen gas. Similar behavior has not been reported previously, and the conclusion regarding underlying mechanisms requires further investigation.Green Open Access added to TU Delft Institutional Repository 'You share, we take care!' - Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Energy TechnologyChemE/Materials for Energy Conversion and Storag
Effect of HCl on NO Formation during CO/NH3 Combustion in an Entrained Flow Reactor at 1023-1223 K
No full textBiomass and coal that contain high amounts of chlorine release HCl during combustion. There is no universal agreement regarding the effect of HCl on NO formation. To investigate the effect of HCl on NO formation CO/NH3 combustion experiments and simulations were conducted in an entrained flow combustion reactor at 1023-1223 K. The experimental results show that the HCl addition tends to inhibit NO formation at low temperatures and exhibits promotion effects when the temperature is increasing and a temperature enhancement tends to inhibit NO formation. The simulation results provide evidence that the HCl addition inhibits NO formation by reducing the concentrations of the H O and OH radicals
ROTATIONAL SPECTRA OF THE ACETYLENE-HCl AND ETHYLENE-HCl DIMERS
No full textAuthor Institution:The microwave spectra of the acetylene-HCl and ethylene-HCl dimer obtained by using a pulsed. Fourier-transform spectrometer with gas being pulsed into a Fabry-Perot cavity is described. The J =2 and J 2 R branches for three isotopes of both dimers are analyzed. All rotational transitions show hyperfine structure originating from the nuclear quadrupole coupling of the Cl nucleus () with the rotational angular momentum. Nuclear quadrupole coupling constants are obtained for the Cl nucleus in all three isotopes of both dimers and is obtained for deuterium in the ethylene DCl dimers. The equilibrium structure of both dimers has symmetry with the HCl on the symmetry axis and the hydrogen pointing towards the double and triple bonds. The equilibrium structure of the ethylene-HCl dimers is non-planer
LASER-EXCITED VIBRATIONAL FLUORESCENCE OF HCl AND THE LASER
No full textWork supported by the National Science Foundation. J.R. Airey, J. Quantum Electronics 3, 208, (1967).Author Institution: Department of Chemistry, University of CaliforniaThe light produced by a pulsed Hel laser has been used to excite the molecular vibration of HCl. The vibrational energy transfer rates in , HCl-HI and other gaseous mixtures were measured. Since the vibrational energy is transferred rapidly from HCl to , laser action of is obtained by mixing into the pulsed HCl laser system. By using laser quanta as an indicator, we have effectively titrated the number of HCl vibrational quanta produced in the chemical reaction
Electrochemical Characterization of Ti5Si3/TiC Nanocomposite Coating in HCl Solution
No full textA novel Ti5Si3/TiC nanocomposite coating was successfully engineered onto Ti-6Al-4V alloy substrate by double glow discharge plasma technique. The microstructure of the newly developed nanocomposite coating was characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The results showed that the nanocomposite coating exhibits cauliflower-like structure composed of Ti5Si3 grains with an average grain size of ~15 nm and irregular TiC nanoparticles located at the boundaries of cauliflower-like architecture. The electrochemical behavior of the nanocomposite coating and the reference materials (i.e., monolithic Ti5Si3 coating and uncoated Ti-6Al-4V alloy) was evaluated in 5 wt.% HCl solution by a variety of electrochemical techniques, including open circuit potential measurement, potentiodynamic polarization, electrochemical impedance spectroscopy and Mott-Schottky analysis. The results revealed that the corrosion resistance of the Ti5Si3/TiC nanocomposite coating is slightly lower than that of the monolithic Ti5Si3 nanocrystalline coating, but obviously higher than that of uncoated Ti-6Al-4V in 5 wt.% HCl solution
MICROWAVE AND INFRARED ELECTRIC-RESONANCE OPTOTHERMAL SPECTROSCOPY OF HF-HCl AND HCl-HF
No full textAuthor Institution: Molecular Spectroscopy Division, National Institute of Standards and TechnologyMicrowave and infrared spectra of HF-HCl and HCl-HF have been obtained using a molecular-beam electric-resonance optothermal spectrometer, which operates by quadrupole-field focusing of polar molecules onto a bolometer detector. The HF-HCl microwave measurements extend to the previous results of Janda. Steed, Novick, and Klemperer, allowing the determination of the dependence and asymmetry of the Cl quadrupole coupling constant. For the metastable HCl-HF isomer no previous spectroscopic measurements have been reported. Here, microwave spectra are observed for the and 1 states and interpreted in terms of an L-shaped hydrogen-bonded structure for the complex, with a 3.235 A center-of-mass separation between the HF and HCl subunits. The Dj distortion constants indicates that the harmonic stretching force constant for HCl-HF is -35\% larger than that of HF-HCl. Infrared spectra of the -0 and 1-0 subbands of the H-F stretching band for HF-HCl and of the subband of the H-F stretch for HCl-HF are also reported. The vibrational predissociation linewidths depend on vibration, state, isotopic species, and isomer excited
C6H5NH2 effect on the corrosion inhibition of aluminium in 0.5 M HCl
No full textIn this paper, C6H6NH2 (aniline) effect on the corrosion of aluminium in 0.5 M (i.e. mol/L) HCl medium was studied using gravimetric method by weight loss measurements and electrochemical technique of corrosion potential and potentiodynamic polarization by cyclic voltamery (CV) instrumentation. By these techniques, corrosion rate obtained from aluminium specimens, in 0.5 HCl test-solution having different concentrations of the hydrogen-containing C6H6NH2 chemical, were requisitely analysed. Results showed that the potentiodynamic corrosion rate excellently correlated (R = 98.94%, Nash-Sutcliffe efficiency = 97.89% and ANOVA p-value = 0.0314) with function of the gravimetric corrosion rate and C6H5NH2 concentration. Both experimental and correlated prediction models identified 0.043 mol/L C6H5NH2 with optimal inhibition efficiency performance η = 84.11% by the experimental or η = 81.15% by the predicted models. Fittings of experimental and correlated data showed the data models followed the Langmuir adsorption isotherm from which favourable adsorption and prevalent physisorption were indicated as the C6H5NH2 corrosion-protection on aluminium metal in the 0.5 M HCl medium
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