Renewable and Sustainable Energy Engineering Technologies, Adaptation and Evaluation of Small Scale Portable Wood Powered Bread Baking Oven

Bread is a staple food that is closely connected to people's daily lives, and the process of making bread is a significant part of food production. Baking is the last and most critical stage in bread-making, where dough typically made from flour, water, and leavening agents is transformed into a food item with unique taste and texture through the application of heat in an oven. In Ethiopia, most bakers are located in towns and use either traditional wood-fired ovens made from mud bricks or imported modern ovens. These ovens are often criticized for their high wood usage and high cost, making them unsuitable for small-scale or household use. To address this, this study aimed to adapt and assess a small-scale, portable, wood-powered bread-baking oven (WPBBO). The oven, which has two baking compartments with one baking chamber and two combustion chambers, was evaluated based on its baking capacity, efficiency, and the weight loss of the bread produced. When fully loaded, it can bake 160, 32, and 8 loaves of bread in each batch across the two compartments, with a baking efficiency of 86.9% and a baking capacity of 96.6%, along with an average weight loss of 12.6%. The oven's performance in terms of baking time was tested for 100 g, 500 g, and 2000 g loaves of bread, showing an average baking time between 15 - 25 minutes. A single feeding of 5 kg of biomass fuel into each fire chamber was sufficient for a 25-minute baking cycle. The study concluded that the oven performs well within a 15-20 minute range for a standard bread loaf. Based on this evaluation, the wood-powered oven is recommended for use in domestic settings and small-scale businesses, as it is suitable for rural areas where electricity is not available, as well as in pre-urban and urban communities.