International Journal of Modern Research in Engineering and Technology (IJMRET) www.ijmret.org Volume 7 Issue 4 ǁ April 2022. www.ijmret.org ISSN: 2456-5628 Page 1 Mathematical Model Development for Design Improvement of a Gas-Fired Pyrolysis Reactor Akinbomi, Julius Gbenga 1, * and Ogunwumi, Olawale Theophilus 2 1,2 Department of Chemical Engineering, Faculty of Engineering, Lagos State University, Epe, Lagos, Nigeria Abstract: Conversion of wastes into valuable resources may not be effective with defective equipment. The aim of the study was to develop a mathematical model using data generated from the laboratory study of thermal efficiencies and air pollution impacts of locally fabricated liquefied petroleum gas (LPG) burners. This was in order to obtain optimum number of burner holes and air-to-fuel (LPG) ratio for design improvement of air-fuel intake port of a gas-fired pyrolysis reactor. The data were modeled for the effects of burner hole type, fuel flow rate and air-fuel ratio; on the thermal efficiencies and emission characteristics of the LPG gas burners. Regression model for thermal efficiencies gave a good fitness to experimental data and is significant for predicting thermal efficiency response variable with high correlation coefficient of 99.97%. Predicted data for thermal efficiency gave highest value of 69% when LPG flowrate and burner hole type were at 1.0 litre/min and 144 respectively. Analysis of characteristic emissions from the gas burners including CO, NOx and TSP emissions showed that environmental effect of combustion using the gas burners is minimal when operating at highest gas flowrate and burner hole type. From the results of the data modeling, optimum thermal efficiency, air-to-fuel ratio and lowest emissions were predicted when burner hole type and gas flowrate were optimal at 144 and 1.0 litre/min. Keywords: Mathematical modeling, pyrolysis, gas burners, air-fuel ratio, emissions, thermal efficiency I. Introduction The ineffective management of disposal of non- biodegradable polymeric wastes, including rubber tyres, plastic bottles, diapers, nylon wastes, among others; is a major challenge in increased rate of consumption of the polymeric materials in recent times. Disposal of the non-biodegradable polymeric wastes through land filling, open burning or ocean dumping is associated with damaging environmental and health implications. For example, burning of tyres outdoor, leads to the release of large amount of dangerous, toxic and carcinogenic inorganic substances into the atmosphere while tyres buried underground decompose under natural conditions for more than 100 years [1] . The contact of these decomposing tyres with rainwater and groundwater leads to the formation of organic toxins and carcinogenic chemical compounds. To minimize the negative effects of improper disposal of non- biodegradable polymeric wastes, different environmentally-friendly techniques, including pyrolysis, have been developed to manage the disposal of the polymeric wastes. Pyrolysis is the thermal or catalytic decomposition of materials at elevated temperatures in an inert atmosphere or in the absence of oxygen. It is a technique that is being used as an environmental friendly tool for waste valourization [2-6]. Pyrolysis is an effective process for the control of environmental pollution caused by solid waste materials especially non-biodegradable polymeric wastes. Besides the environmental benefits, valuable products such as activated carbon, diesel oil, fuel gases, bitumen, among others can be obtained from the pyrolysis technique [6-11] . Meanwhile, developing and designing a pyrolysis process to meet its specification and requirement entails provision and analyses of mathematical models which will describe its kinetics, mechanism and optimization [12]. Pyrolysis models are gaining importance not only because it is studied as an independent process but because it is an initial step in gasification or combustion process[12]. Several researchers have carried out different studies on