www.astesj.com 252 Combustion Flame Temperature Considering Fuel and Air Species and Optimization Process Prosper Ndizihiwe 1,* , Burnet Mkandawire 2 , Kayibanda Venant 3 1 University of Rwanda, Renewable Energy, Kigali, 4285, Rwanda 2 Malawi University of Business and Applied Sciences, Mechanical Engineering, Blantyre, Private Bag 303, Malawi 3 University of Rwanda, Electrical Engineering, Kigali, 4285, Rwanda A R T I C L E I N F O A B S T R A C T Article history: Received: 05 May, 2021 Accepted: 24 June, 2021 Online: 03 August, 2021 Estimation of optimal Air or oxygen is important for the combustion process to be efficient and produce more energy. This is to be based on each component of the fuel and the air, considering their respective pressure and density. At first, this research investigates the role of 2 , 2 , 2 present in combination with 4 , and the air on the flame temperature; using simulation with Cantera 2.4. Results have been compared and calibrated with field data from KivuWatt company. It then demonstrates the way to achieve optimum Air Fuel Ratio (AFR) for the various species of the fuel. The results estimated the flame temperature by means of the percentages of all species of the fuel and the air, as well as various conditions of pressure and temperature. Finally, it combines all to show different values of optimum AFR at various species percentages; and uses a python program to create an AFR calculator available online through the link provided. Keywords: Air and fuel Equivalence ratio Carbon dioxide Stoichiometry Species of fuel Nomenclature: : Air-Fuel Ratio , : balancing constants : Actual quantity of oxygen ɸ: Equivalence ratio : Mass : Enthalpy υ: The number of moles : The atomic weight : Reference temperature : Heat capacity : Density : Pressure : The temperature : Oxygen : Hydrogen : Carbon : Sulphur : Perfect gas constant 1 to 6 , coefficients of the thermodynamic system Subscript , , , , , : fuel, any species, inlet, oxygen total, and formation respectively 1. Introduction The combustion within the boiler burns fuel to create heat energy. The burning of fuel is the reaction of fuel with oxygen present in the air. The amount of fuel that can be burnt is limited by the oxygen present [1]. When all the fuel is not burnt, a part of it stays in the boiler and the other quantity goes to the atmosphere. This is the loss that reduces efficiency, and tends to pollute our environment [2]. Most of the fuels used in the boiler are hydrocarbons which release hydrogen and carbon as residuals, along with heat and pressure when burnt [3]. The quantity of these residuals and their temperatures impact the performance of the plant including the [4]. The quantity of the exhaust depends both on the composition of the fuel, the composition of the air, and the effectiveness of the combustion [5]. In general, the global reaction of combustion is like + 2 → (1) Let us see the combustion by taking into account the residuals within the fuel and the air. 1.1. Consideration of fuel and its impurities of the field and application The general fuel formula is given by its composition of carbon, hydrogen, sulfur, oxygen, and nitrogen. So it is [6] Combustion equation is ASTESJ ISSN: 2415-6698 * Corresponding Author: Prosper NDIZIHIWE, Kigali, +25 0783058498 & ndizihiweprosper@gmail.com Advances in Science, Technology and Engineering Systems Journal Vol. 6, No. 4, 252-258 (2021) www.astesj.com https://dx.doi.org/10.25046/aj060429