Kenya-Malawi Biomass Energy Project Summary Report

This project is intended to carry out an engineering, social and economic evaluation of food processing in the rural areas of Malawi and Kenya. The aim is to collect the information necessary for designing a clean and low-cost energy system for co-generation of heat and electricity from agricultural waste to support food processing. the objective of this research is to survey the following aspects: Technical: The existing energy-intensive food processing industries in the partner countries. Social: Current and historic social resources: e.g. the designers, operators and beneficiaries of the existing processes; Locally available skills for designing and operating alternative energy solutions. End-user: Current and historical regional usages of the agricultural products; Local views on existing problems and their desired goals

A Study on Agricultural Residues as a Substitute to Fire Wood in Kenya: a Review on Major Crops

For Kenya, the use of fire wood is enormous that the exploitation of other energy resources such as biomass from agricultural residues is little known. Therefore, the main aim of this study is to investigate agricultural residues estimates for use as a substitute to fire wood and charcoal in Kenya. This solution is in line to the urgent needs of finding the alternative for the depleting fossil fuels. The study found that Kenya agricultural residue energy potential is about 187,000 TJ which enough to substitute fire wood in most regions if converted with suitable technologies. If all the available agricultural residues are used as substitution fuel for fire wood, Kenya could reinstate the 10% forest cover as recommended from the current 1.7%

Comparative Study of Composite Made from Ensete False Banana Fibres and Polyethylene with Block Board

This paper is an effort to utilize abundant availability of natural fibres and waste plastics for the development of composite materials based on polymer and particles of natural fibres for conservation of natural resources such as forests. Ensete false banana (EFB) fibres were used as reinforcement to obtain composites with melted waste polyethylene bottled as matrix phase. The composites were prepared by means of compression moulding, and then the effects of fibres loading on mechanical properties such as impact strength, flexural strength, and wear resistance were investigated. Water uptake was also studied. It was observed that the flexural modulus, compressive strength and flexural strength of treated EBF reinforced PE increased linearly with increment of fibres loadings. This trend was similar for impact strength where it exhibited a slight reduction at the initial stage but increased later as the fibres loading increased. It was also observed the water absorption increased with increase in fibres loading. Machining operations such as grinding, milling, drilling and cutting can be performed on the composite. The study has demonstrated that the optimum fibres loading for the best performance of the composite achieved was 30 wt%. The composite produced has a high potential as alternative block board materials. Keywords: Ensete false banana, Block board, fibres, plastics waste, composite

Combustion Characteristics of Mui and Taru Basin Coal in a Fluidized Bed Combustor

Coal reserves at Mui and Taru in Kitui and Kilifi counties in Kenya are estimated to provide over 400 million tons. Being new discoveries, their properties were investigated using the ASTM standards, while the combustion characteristics were studied in a fluidized bed combustor (FBC). Proximate analyses of the Mui1, Mui2, and Taru coal samples were as follows: moisture content 3.75, 5.48, and 3.53%; volatile matter 59.25, 58.05, and 55.10%; ash content 9.25, 11.48, and 24.63%; and fixed carbon 27.80, 25.00, and 16.75%, respectively. Ultimate analysis for Mui1, Mui2, and Taru coal samples is as follows: sulphur wt.% 1.94, 1.89, and 1.07; carbon 65.68, 60.98, and 51.10%; hydrogen 5.97, 5.70, and 5.09%; nitrogen 0.92, 0.94, and 1.00%; and oxygen 11.62, 12.33, and 11.13%, respectively. Temperature–weight loss analysis showed that for Mui and Taru basin coal, devolatilization starts at 200°C and 250°C, and combustion was complete at 750°C and 650°C, respectively. The maximum temperature obtained in FBC was 855°C at 700 mm height, just above the point of fuel feed, while the minimum was 440°C at height of 2230 mm. Maximum pressure drop was 1.02 mbars at 150 mm, while minimum was 0.67 mbars at 700 mm from the base. Gross calorific values were Mui1 coal, 27090 kJ/kg (grade A), Mui2 coal, 25196 kJ/kg (grade B), and the Taru coal, 21016 kJ/kg (grade C). Flue gas analysis for Taru and Mui coal gave hydrogen sulfide as 20 ppm and 6 ppm, maximum carbon monoxide of 2000 ppm at 600°C, and a decrease in oxygen as combustion progressed to a minimum of 15%, followed by an increase to 20.3%, suggesting depletion of coal. Based on the findings, the coal samples were suitable for commercial use

Solar Photovoltaic Systems: A Technical and Economic Feasibility Design Approach with Homer Pro

With the declining cost of solar photovoltaic (PV) modules and batteries used for energy storage, many users are now shifting towards solar energy because of its renewable nature and availability. Though this is a great step to combat climate change, most of the solar systems installed always fail due to poor system sizing. For this reason, optimal systems are required to be deployed. This paper presents a technical and economic feasibility design approach for a solar PV system using Hybrid Optimization of Multiple Energy Resources (HOMER) Pro software. The design is based on site-specific data collected from Moi University in Kenya. The temperature and solar radiation data were collected from the weather station of the university, while the power demand data was collected from the Margaret Thatcher Library of the university using the PCE-360 power analyzer.  The simulation results show that a 100kW solar PV system is required to power the Margaret Thatcher library with a financial investment of KES 32,000,000. This system is strongly recommended to be used by the university as it will ensure reliability of power supply for students to study and also save on costs incurred on utility bills

Design and Performance Evaluation of a Hydronic Type Compost Heat Exchanger

While much research has been published on the Compost Heat Recovery Systems (CHRs), little has been documented on the design and performance evaluation of the Hydronic compost heat exchangers using numerical and computational methods, occasionally resulting in compost process inhibition. A CHRs (0.036 m3/7.2 m2) Hydronic-type heat exchanger and 12.43 m2/2.83 m3, compost reactor (CR), was designed and developed with the main objective of evaluating the design and its performance. The numerical design and performance evaluation was achieved by using Kern’s and the effectiveness and Number of Transfer Units methods (ε-NTU), respectively. Empirically, data were captured by using the Polytetrafluoroethylene (PTFE) thermocouples connected to the TC-8 Picolog Data loggers. Data validation (empirical and mathematical), was achieved by modifying a free computer-based software developed by the Chemical Engineering Calculations (CHECAL), into a Hydronic Compost Heat Exchanger design and performance evaluation software (HYDROCOHE). Between the HYDROCOHE and numerical, and between empirical and HYDROCOHE, R2 values of 0.99938–0.9995, and R2 of 0.99269–0.9432 with the effectiveness of 0.4853–0.4848 were achieved with 0.99 kW-empirical and 2.10 kW-HYDROCOHE, respectively. The power disparity may be ascribed to the compost reactor’s insufficient thermal insulation. Counterflow arrangement was more effective (0.4766) than crossflow (0.4622) and parallelflow (0.4430) setups. Parallelflow heat exchanger system, therefore, has the potential to extract heat steadily, minimizing the composting cycle inhibition. Further work on the impact of various flowrates on the direction of flow and heat extraction is recommended

Kenya-Malawi Biomass Energy Project Summary Report

This project is intended to carry out an engineering, social and economic evaluation of food processing in the rural areas of Malawi and Kenya. The aim is to collect the information necessary for designing a clean and low-cost energy system for co-generation of heat and electricity from agricultural waste to support food processing. the objective of this research is to survey the following aspects: Technical: The existing energy-intensive food processing industries in the partner countries. Social: Current and historic social resources: e.g. the designers, operators and beneficiaries of the existing processes; Locally available skills for designing and operating alternative energy solutions. End-user: Current and historical regional usages of the agricultural products; Local views on existing problems and their desired goals