A study of energy recovery from municipal solid waste was undertaken. The energy content of the solid waste is 12MJ/kg. The elemental composition shows that the municipal solid waste contains 50% and 5% of carbon and hydrogen respectively. The energy flow (exothermic and endothermic) and thermal degradation analysis were carried out using differential scanning calorimetry and thermo-gravimetric analyser respectively. Experiments were performed at heating rate of 10 K/min, 20 K/min, 30 K/min and 40 K/min in the nitrogen atmosphere at temperature between room temperature and 1273 K. The thermal degradation kinetic parameters values of activation energy (E a ) ranged from 205.9 to 260.6kJ/mol. It has been observed that municipal solid waste is less reactive to combustion as compared to coal and biomass, but its reactivity can be improved through pre-treating process so as to reduce noncombustible materials such as oxygen and ash content. Also pyrolysis and gasification can be used to convert MSW to liquid or gaseous fuel.

In this study, a Computational Fluid Dynamics (CFD) technique was used to develop a model for the simulation and flow conditions of the incinerator. The CFD technique are based on subdividing the volume of interest, i.e., the combustion chamber (or other parts of the plant) into a grid of elementary volumes. The relevant equations of conservation (mass, momentum, energy) are then applied to each of those elements, after defining all inputs, outputs and boundary conditions. The resulting system is then integrated from start to finish, after introducing momentum, mass and heat transfer. The objective of the study was to evaluate and optimize the performance of locally available incinerators in Tanzania. The small scale municipal solid waste incinerator modelling was done by using a fluent solver. The case study of the existing incinerator at a Bagamoyo hospital in Tanzania was used as a model and the obtained values were compared with simulated results and other publications for validation. The design optimization using CFD techniques to predict the performance of incinerator showed the deviation of input air by 14%, the mass flow rate by 26.5%,

Waste resulting from economic activities has been an integral part of every human society. Effective waste management is considered to be consistent with improved quality of life through removal of potential hazards of uncontrolled disposal. Recent years has witnessed a number of sustainable energy recovery technologies developed to divert solid waste destined for landfills. Waste management is a global problem and therefore development of energy recovery technologies and at the same time serving dual purpose in its reduction has become a priority in recent years. The present study reports kinetics properties and thermal behavior of pine sawdust and municipal solid waste (MSW) using thermogravimetric analysis (TGA) and thus providing theoretical basis for development of energy recovery technologies. Results of this study have shown that the activation energy of both MSW and pine sawdust varies with temperature. The analysis of pine sawdust shows that it has activation energy (Ea) values of 26.19 kJ/mol., 87.46 kJ/mol. and 54.46 kJ/mol. At respective temperature ranges between 350 – 400K, 550 – 650K and 700 800K.  MSW has activation energy between 72.91 kJ/mol. and 139.1 kJ/mol. at temperature ranges between 700 – 900 K and 500 – 600 K respectively. The estimated value of pre-exponential factor for pine sawdust was determined to have the values of 2.46 x 104, 1.6 x 1010 and 5.32 x 1016 (s-1) with temperature ranges between 350 – 400 K, 550 – 650 K and 700 800 K respectively. Municipal solid waste has the values of 3.01 x 1012 and 7.31 x 103 (s-1) with a temperature range of 500 – 600 K and 700 – 900 K respectively. From these findings, it has been determined that MSW and pine sawdust available in Arusha and Kilimanjaro possess energy recovery potentials.

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A grid connected microgrid connects to the grid at a point of common coupling. Due to the great inertia of the grid which accelerates and decelerates the generator when its frequency tends to deviate, the grid connected microgrid operates at a frequency of the infinity bus. Frequency instability is one of the major challenges facing the grid connected microgrid during islanding. The power demand variation causes the variation in rotor speed, resulting to frequency deviation. Frequency can be brought back to standard by varying the power generation to match with the varying load. The performance of the frequency stability control system at Mwenga hydroelectric microgrid has been studied. Through site visitation, the power demand and generation status data were collected and analysed for model preparation. The results of the study indicate that, during islanding, the Mwenga rural electrification project is observed to be subjected to power imbalance which leads to frequency instability. Although the frequency control system tries to keep the system at a nominal frequency by maintaining the continuous balance between generation and varying load demand, however the system still operates with large magnitude of overshoot, undershoot and longer settling time.