Étude de la combustion des boues de barattage dans l’industrie de karité en Afrique de l’Ouest

Details

Supervisors

Jeanmart, Hervé

Faculty

Ecole polytechnique de Louvain

Degree label

Master [120] : ingénieur civil mécanicien, à finalité spécialisée

Abstract

enThe aim of this thesis is to study the combustion of churning sludge in the West African shea industry, in order to provide dimensional and operational recommendations for the design of an on-site burner. As part of the Biostar project for energy transition in Africa, the burner is designed to meet the specific needs of small and medium-sized enterprises in the shea industry. The aim is to replace the wood used in the shea kernel roasting and cooking process with churning sludge, a by-product of shea butter production. The theoretical concepts involved in developing this burner relate to biomass composition (moisture, calorific value, chemical composition) and the various stages of complete combustion (drying, pyrolysis, primary and secondary combustion). To master these concepts, it is necessary to analyze the influence of specific factors such as fuel power, excess air, carbon monoxide emissions, natural draft, primary and total airflows, and the associated typical values. In order to gain a better understanding of the combustion process, an asymmetrical burner with a theoretical output of 10 kW was designed for the experiment. For this, it is necessary to characterize the biomass used, make assumptions about its sizing and plan the experiments strategically. The measurements and observations made during experimentation on the prototype will enable us to make recommendations for the design of a similar burner on a larger scale. In this work, the qualitative part is more preponderant than the quantitative. Given the large number of factors involved, it was difficult to establish clear correlations between the various parameters measured. However, this diversity in the factors tested enabled us to determine their positive, negative or neutral impact on combustion. During stable phases, carbon monoxide emissions were well below 4000 ppm, but power levels were too high (up to 15 kW fuel power). The experimental prototype designed in this work therefore enables adequate biomass combustion, but an optimum has not yet been achieved. In the discussion section, we'll be taking a closer look at the issue of biomass flow and the management of air-tightness problems in the tank.