Energy and Power Engineering, 2012, 4, 28-33 http://dx.doi.org/10.4236/epe.2012.41004 Published Online January 2012 (http://www.SciRP.org/journal/epe) Reduced Detailed Mechanism for Methane Combustion Abdelouahad Ait Msaad 1 , Abdeltif Belcadi 1 , Mustapha Mahdaoui 1 , Elhoussin Aaffad 2 , M’hamed Mouqallid 1 1 Laboratory of Mechanics, Energetics and Processes, Ecole Nationale Supérieure d’Arts et Métiers, Moulay Ismail University, Meknes, Morocco 2 Laboratory of Heat and Mass Transfer, FST of Mohammedia, Hassan II University, Casablanca, Morocco Email: msaadabdelouahad@yahoo.fr Received December 2, 2011; revised December 28, 2011; accepted January 10, 2012 ABSTRACT Simulated results from a detailed elementary reaction mechanism for methane-containing species in flames consisting of nitrogen (NO x ), C 1 or C 2 fuels are presented, and compared with reduced mechanism; this mechanism have been constructed with the analysis of the rate sensitivity matrix f (PCAF method), and the computational singular perturba- tion (CSP). The analysis was performed on solutions of unstrained adiabatic premixed flames with detailed chemical kinetics described by GRI 3.0 for methane including NO x formation. A 9-step reduced mechanism for methane has been constructed which reproduces accurately laminar burning velocities, flame temperatures and mass fraction distributions of major species for the whole flammability range. Many steady-state species are also predicted satisfactorily. This mechanism is especially for lean flames. This mechanism is accurate for a wide range of the equivalence ratio (1, 0.9, 0.8, and 0.7) and for pressures as high as 40 atm to 60 atm. For both fuels, the CSP algorithm automatically pointed to the same steady-state species as those identified by laborious analysis or intuition in the literature and the global reac- tions were similar to well established previous methane-reduced mechanisms. This implies that the method is very well suited for the study of complex mechanisms for heavy hydrocarbon combustion. Keywords: Detailed Mechanism; Reduced Mechanism; PCAF Method; CSP Algorithm 1. Introduction The primary aim of most recent research in applied and industrial chemistry is to contribute to the protection of the environment. Environmental friendly design and control of chemical processes means that fewer pollut- ants are produced and fewer by-products are formed. To achieve it, very detailed knowledge of chemical proc- esses is needed. The ultimate level of information is when the process is described by a detailed reaction mechanism. Such reaction mechanisms are available for many important processes and the parameterized tem- perature and pressure dependence of all rate coefficients. This mechanism is usually utilized in the following three steps. First, the detailed reaction mechanism is created and validated using all available experimental informa- tion [1]. The next step should be the analysis of the mechanism and a characterization of the limits of its ap- plication. Simulation of a large reaction mechanism might consume too much computer time, when applied for real-time process control or in a computational fluid dynamics (CFD) code that simulates a complex flow field. Therefore, the final step can be the reduction of the reaction mechanism to an almost equivalent smaller com- putation model [2]. This paper does not deal with the creation of a detailed reaction mechanism, but discusses possible ways for the analysis and reduction of such mechanisms. The chemical process represented in the reduced me- chanism related to the slowest chemical. Inspection of the additional chemical process introduced by increasing the steps in the reduced mechanism will reveal additional features of the flames dynamics. In this work, we reduced the detailed mechanism of the methane combustion in air by using the PCAF method combined with the CSP algorithm at high pres- sure 40 atm to 60 atm [3,4]. We consisted to determine and analyses the global reduced mechanism of the meth- ane/air combustion (GRI-3.0) [5]. 2. Construction of Global Reduced Mechanisms Detailed chemistry calculations have been carried out Copyright © 2012 SciRes. EPE