General Information
    • ISSN: 1793-821X
    • Frequency: Quarterly (2013-2014); Bimonthly (Since 2015)
    • DOI: 10.18178/JOCET
    • Editor-in-Chief: Prof. Haider F. Abdul Amir
    • Executive Editor: Ms. Julia S. Ma
    • Abstracting/ Indexing: EI (INSPEC, IET), Electronic Journals Library, Chemical Abstracts Services (CAS), Ulrich's Periodicals Directory, Google Scholar, ProQuest and DOAJ.
    • E-mail: jocet@ejournal.net
  • Jul 03, 2017 News! JOCET Vol.4, No.5 has been indexed by EI(Inspec)!   [Click]
  • Jul 25, 2017 News! JOCET Vol. 6, No. 1 is available online now. 16 papers which cover 5 specific areas are published in this issue.   [Click]
Editor-in-chief
School of Science and Technology Universiti Malaysia Sabah, Malaysia.
I would like to express my appreciation to all authors, reviewers and edtors.
JOCET 2018 Vol.6(1): 56-66 ISSN: 1793-821X
DOI: 10.18178/JOCET.2018.6.1.436

Numerical Study of Nitrogen Oxides (NOx) Formation in Homogenous System of Methane, Methanol and Methyl Formate at High Pressures

J. M. Ngugi, P. N. Kioni, and J. K. Tanui
Abstract—The main aim of this study is to determine the effect of equivalence ratio and pressure on the formation of nitrogen oxides (NOx) in homogenous ignition of methane/air, methanol/air and methyl formate/air. A constant volume reactor of 200 cm3, at initial temperature of 1300 K and at pressure, P, ranging between 1-50 atmospheres has been considered. The equivalence ratios of the test mixtures have been varied from 0.7 to 1.3. This represents the lean-to-rich region which is most relevant to the conditions in an internal combustion engine. CH4, CH3OH and CH3OCHO flames have been modelled with different detailed reactions mechanisms, which have been modified and extended to incorporate high pressure oxidation reactions. Flame structures, minor species and NOx time histories have been plotted for the three fuels under different conditions. The results obtained show that the formation of NOx vary with pressure and equivalence ratios. NO mole fraction profiles and other radicals; N2, N, O, OH, CH, HCN, and N2O that are dominant in formation of NO have been compared. It is established that in homogenous system, NO formation is high in CH4 at lean and stoichiometric conditions while CH3OCHO has high NO at rich conditions for all pressures. At fuel lean and stoichiometric conditions, as pressure increase from 1 to 50 atm peak NO formed in all the three fuels increases. At fuel rich condition, as pressure increase from 1 to 50 atm peak NO formed in all the three fuels decrease. High concentration of N2, O, OH and high temperatures observed in all flames indicate that Zel’dovich mechanism is the main NO formation route in a homogenous reactor.

Index Terms—Methane, methanol, methyl formate, nitric oxide, homogenous system.

J. M. Ngugi, P. N. Kioni and J.K. Tanui are with Department of Mechanical Engineering, Dedan Kimathi University of Technology P.O. Box 657-10100, Nyeri, Kenya (e-mail: ndirangukioni@dkut.ac.ke).

[PDF]

Cite:J. M. Ngugi, P. N. Kioni, and J. K. Tanui, "Numerical Study of Nitrogen Oxides (NOx) Formation in Homogenous System of Methane, Methanol and Methyl Formate at High Pressures," Journal of Clean Energy Technologies vol. 6, no. 1, pp. 56-66, 2018.

Copyright © 2008-2016. Journal of Clean Energy Technologies. All rights reserved.
E-mail: jocet@ejournal.net