In sub-Saharan Africa, dependence on wood fuel has caused significant depletion of vegetative resources. Whereas there exist hundreds of improved cooking stoves, many have not reached their maximum potential because their designs are predominantly focused on either fuel efficiency or reduced smoke. This research designed and fabricated an improved charcoal stove using high density rocks and heat retaining techniques. The aim was to retain heat and minimise heat losses in cooking devices with a sole purpose of reducing the amount of fuel used during cooking. The stove design herein incorporates the interaction of physical and thermal properties of granite rocks with heat loss theories to give a thermal efficient unit. The stove was estimated to cost US$ 36 which compared favourably with most of the improved charcoal stoves on international market (US$ 3–50 US$). This study revealed that, by introducing the new stove design and insulation, the granite rocks depicted high thermal storage properties with potential for reducing fuel use by over 78% with reference to the open fire stove. The designed granite rock stove therefore paves way for the use of high density rocks in improved cook stoves to achieve high performance energy efficient systems that can sustainably put to use vegetative resources.

Abstract-

Fuelwood scarcity is evident in south western Uganda, where households are using sorghum and maize stalks for cooking as alternatives to the traditional fuelwood. The aim of the study was to assess the implications of fuelwood scarcity on livelihoods of rural communities in Nyarubuye sub-county in Kisoro district in south western Uganda. Systematic random sampling techniques were used to select participating households for the study. Data were collected using direct observation and interviews, using a structured questionnaire that was administered to 80 households in Busengo and Karambi parishes. Face to face interviews were held with key informants, using a checklist. The study showed that the main drivers of fuelwood scarcity in Nyarubuye Sub-county include: land shortage, rapid increase in population, change of land use from communal forested land to crop growing only, lack of integration of trees on farm, inefficient methods of cooking and brick burning. The study also showed that the implications of fuelwood scarcity on livelihoods in the study area were adverse and greatly affected women, as compared to men. They included sickening of eyes, breathing difficulties, snake bites and body dislocations, increased domestic violence (wife beating) and sexual abuse (rape), school attendance inconsistencies for school going children, loss of tree cover and low crop yields. Suggested strategies to reduce fuelwood scarcity in area include: promotion of on farm tree planting activities (agroforestry) and energy saving technologies, availing alternative energy sources such as electricity, enhancing family planning methods, skilling of communities on income generation enterprises especially girls. A byelaw on school children with emphasis on girls to collect firewood during weekends only should be formulated and enforced.

Jatropha curcas Linn has been identified worldwide as one of the sources of biodiesel. Biodiesel has energy properties close to fossil diesel and can be a potential energy alternative. However, these properties may vary based on soils, plant genetics and agro-climatic conditions in a given geographical location. Several studies on biodiesel production under such conditions have been done elsewhere, but few have been done on J. curcas oil in Uganda. This study analysed the physicochemical properties of J. curcas L. oil for biodiesel production in Nebbi and Mukono districts using American Standards and Testing Methods (ASTM D6751) and European Standards (EN 14214). J. curcas seed kernel contained 51% w/w and 48% w/w of oil with high levels of Free Fatty Acids (1.52% and 1.93%) and acid values (35 and 36 mg KOH/g) for Nebbi and Mukono, respectively; the difference was significant (p ≤ 0.05). Generally, the quality and quantity of the oil from Nebbi were better than those of Mukono, based on the biodiesel standard values. Nevertheless, kinematic viscosity, acidity, potassium and phosphorus content values were found abnormally high (31.46 -33.23 mm 2 /s, 35.23 -36.66 mg KOH/g, 16.50 -20.52 mg/100g and 16.13 -26.02 mg/kg, respectively) for both regions as compared to the standard values (3.5 -5.0 mm 2 /s, 2 mg KOH/g, <5 mg/100g and <10 mg/kg, respectively) of biodiesel for diesel engine. Such properties are very important for engine fuels and if not considered well, may affect engine performance negatively. Therefore adequate treatment of the oil by degumming, etherification and transesterification before use in a diesel engine could avert this difficulty.

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