http://ir.mu.ac.ke:8080/jspui/handle/123456789/7 2026-07-14T15:48:57Z http://ir.mu.ac.ke:8080/jspui/handle/123456789/10333 Title: Combustion characteristics of briquettes of different feed stock of Agricultural wastes a review Authors: Ondari, Brian Overmars; Kimutai, Stephen; Mukubwa, Emmanuel Abstract: Biomass utilization through briquette technology has been used extensively with a number of agricultural feedstocks. Despite having energy policies and implementation framework in some countries like Nigeria regarding biomass waste utilization, some agricultural wastes still remain unexploited nor characterized. This review paper embraced journals mainly from Google scholar published between 2006 and 2025, to establish properties and characteristics of various agricultural wastes and emerging trends. For the agricultural wastes characterized in this paper, the proximate analysis results showed, the average moisture content as 8.48 %, volatile matter 56.91 %, ash content 8.94 % and fixed carbon 24.42 %. These quantities were well within the recommended ranges, showing opportunities for utilization in briquette making. Limited amount of nitrogen and Sulphur content, that is below 1 % and 0.3 % respectively and absence of the same in some feedstocks was observed too. This encourages their utilization since nitrogen and Sulphur are the agents of pollution and being low, provides best substitutes for fossil fuels which have been main donors of the same to the environment. Carbon and hydrogen content averages for these feedstocks were 43.19 % and 5.94 % respectively. This having an influence on fuel combustion, the quantities portrayed, gives an assent for utilization of such feedstock for briquettes making. Average calorific value for briquettes from covered feedstocks was 18796.95 kJ/kg. Thermogravimetric analysis revealed high burning rates at high temperatures with increase in heating rate. Increase in amount of binder, negatively affect calorific values. Highly compacted briquettes result to low combustion rate, but good briquettes in terms of storage and transportation. More research needs to be carried out on other agricultural wastes to add to the available feedstock for briquettes. Further, there’s need to adopt modelling and artificial intelligence which is underutilized in characterization and study of properties of this agricultural biomass. 2025-07-01T00:00:00Z http://ir.mu.ac.ke:8080/jspui/handle/123456789/10331 Title: Modelling energy sector-related greenhouse gas emissions: Trends and insights from Burundi’s overall final energy consumption Authors: Egide, Manirambona; Niyongere, Abraham; Ndayizeye, Martin; Dusabe, Bonaventure; Amiss, Bob K.; Talai, Stephen M.; Kimutai, Stephen K Abstract: Growing concerns over climate change have underscored the need for rapid actions to mitigate its impacts. In that regard, this study sought to assess greenhouse gas (GHG) emissions linked to total final energy consumption in Burundi. By using the Low Emissions Analysis Platform, GHG emissions linked to final energy consumption and their trends were analyzed. The emissions were simulated at the point of emissions and determined in CO2 equivalent at 100-Year GWP “Global Warming Potential”. Results showed that the country’s total final energy demand is anticipated with a rising trend and households are expected to stay the leading overall final energy consumer. Consequently, this increase is expected to drive a rise in GHG emissions. In residential sector, 1753.9 Thousand Metric Tonnes (tmt) CO2 equivalent were emitted in 2015 and about 2095.7 tmt and 2358.7 tmt of CO2 equivalent would be emitted by 2030 and 2040, respectively in that sector. Despite its predicted decline in GHG emissions share, firewood contributed to 87.8 % of the emissions in 2015 in residential sector and is expected to remain the highest contributor of GHG emissions by 2040 with a share of 59.6 %. The GHG emitted by wood fuels represented a large share—73.9 % in 2015—of the total energy demand. However, reference-scenario simulations showed that the situation was expected to shift from 2019 onward, with the share of oil rising to 45.4 % against 41.8 % for firewood. Through implementation of improved cookstoves policy, 903.4 tmt CO2 equivalent would be avoided as compared to the reference-scenario while the adoption of low-emissions power technologies would keep the GHG emissions within the range of 1.0–2.3 tmt CO2 equivalent. The Burundi GHG emissions records presented in this study would support the country in fulfilling both its Nationally Determined Contributions targets and SDG–7 objectives. 2025-11-01T00:00:00Z http://ir.mu.ac.ke:8080/jspui/handle/123456789/10330 Title: Biomass-derived activated carbon from empty fruit bunches for supercapacitor electrodes: Crystallinity and electrochemical analysis Authors: Egbe, Terence Awoh; Mecha, Achisa C.; Kiplagat, Joseph; Kimutai, Stephen K. Abstract: Palm processing industries leave behind huge amounts of biomass annually which are not usually being disposed of sustainably. This study utilizes fast and feasible means of converting empty palm bunch biomass into supercapacitor electrodes. The two-step carbonization-activation method was used to synthesize the highly porous activated carbon, which was used in the electrodes. The resulting materials exhibited patterns similar to that of reduced graphene oxides (rGO) and a maximum specific surface area of 1375 m2/g. The supercapacitor designed from the porous activated carbon exhibits the greatest specific capacitance of 251 F/g at a scan rate of 1 mV/s, under 6 M KOH electrolyte. The corresponding GCD analysis at 100 mA/g current density was 346 F/g, and about 82.9 % of the original capacitance value was retained even after 5000 GCD cycles. The energy density and power density were 17.16 Wh/kg and 180.1 W/kg, respectively. This work does not only provide a feasible route for the management of palm agro-industrial waste, but also produces carbon materials whose electrochemical performance are competitive to state-of-the-art biomass-derived carbon, offering a sustainable pathway for electrochemical energy storage. 2026-04-01T00:00:00Z http://ir.mu.ac.ke:8080/jspui/handle/123456789/10328 Title: Mathematical modeling of combustion characteristics of agricultural waste briquettes Authors: Ondari, Brian; Kimutai, Stephen Kibet; Mukubwa, Emmanuel Wanyama Abstract: Rapid population increase coupled with industrialization has led to rise in global energy demand leading to skyrocketing of energy prices. Diversification in energy resources is essential to reduce overdependence on certain resources. Agricultural wastes remain a promising energy resource to be exploited. Laboratory experimental analysis is time consuming and costly. This fueled the adoption of modelling as an alternative to laboratory analysis. Different models such as computational fluid dynamics (CFD), artificial neural network (ANN), and ANFIS fuzzy logic have been used by various researchers. Buckingham pie theorem together with MATLAB was used in this research to evaluate the properties and combustion characteristics of assorted agricultural wastes. The properties modelled were; porosity, density, shatter resistance, higher heating values, burnout time, burning rate, ignition time and efficiency. The factors that affect each of the properties negatively and positively were determined from the models. The significance of each property and characteristics were articulated. The limitations and assumptions of the models were also highlighted. It is recommended that further research incorporating artificial intelligence in the models needs to be exploited aid in reduction of experimental analysis costs and time. Other agricultural wastes which have not been characterized for need to exploited. This will further reduce overdependence on conventional resources such as fossil fuels which are not only getting depleted at an alarming rate but also led to environmental degradation. 2026-02-01T00:00:00Z