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In the present study a thorough characterisation of biomass residue obtained from bio diesel production is done. The experiments are performed in the State University of Campinas in Sao Paulo, Brazil. It also investigates the feasibility to carry out thermo chemical energy conversion processes like pyrolysis and gasification on the biomass residues. The residue obtained after oil extraction from the seeds of Jatropha curcas and glycerol – a by product of bio diesel production process are the samples characterised. The samples are subjected to proximate analysis, calorimetry and TGA- thermo gravimetric analysis to characterise. Moreover a literature survey of thermo chemical process likes pyrolysis and gasification is carried out. It was found that in the test sample of Jatropha curcas residue the volatiles are in a range of 67-70 wt%, fixed carbon content 18-21 wt% and ash 6-13 wt%. The average calorific power of the three Jatropha curcas residue samples was 20.5 MJ/Kg, 20.63 MJ/Kg and 21.24 MJ/Kg respectively. While in case of glycerol it was 25.60 MJ/m3. The maximum weight loss for Jatropha curcas residue occurs in the temperature range of 330-350 0C and for glycerol it is in range of 285-3000C. It was concluded that it is technically and economically feasible to gasify the residue of Jatropha curcas owing to it high calorific power and volatile matter content. Jatropha curcas residue also has a high ash content so special design consideration should be made to handle ash while designing its gasification system. In case of glycerol, technically, it can be gasified to convert it into high value products but it is necessary further study in order to determine if it is economically feasible.

This master thesis is based on collaboration between the division of Energy System Analysis at the Swedish Royal Institute of Technology, KTH-dESA, and the African Development Bank, AfDB. The work has been carried out both at KTH (Stockholm, Sweden) and at AfDB (Tunis, Tunisia). The KTH-dESA – AfDB collaboration is related to previous projects, for example AIKP, the African Infrastructure Knowledge Program, which in turn is the result of a previous collaboration with the World Bank that led to the comprehensive knowledge program AICD, African Infrastructure Country Diagnostic. As in AIKP, a key part of AICD is to estimate infrastructure investment needs for the power sector.The main objective of this thesis is to create mathematical models of the power sectors in African countries.The output of these models shows, given the parameters used, what investments, power technologies and fuels that gives the lowest net present value for the modelling period (2010-2030 with focus on 2014-2020). The models developed will then be used to populate an Internet application hosted by AfDB. The application was earlier hosted by the World Bank. To develop the models, the free and open source software ANSWER OSeMOSYS is used. The program is developed in order to make long-run optimization models(Howells et al., 2011). Input data to the models was initially supposed to be provided by AfDB. This data was not available in time why temporary data, partly provided from KTH-dESA, is used and the number of countries investigated in this thesis is reduced to four instead of the original 18 countries.The models of the four countries are functional, even though the results of the simulations are not yet final. This is caused by the fact that focus has been put on the creation of the models rather than the results, since the models are to be re-populated with up-to-date data from AfDB. Generally, hydropower and coal STPP are commonly used power sources in the simulation results. The results of Egypt have a large share of technologies fueled by natural gas, which distinguishes the country from the other three. Also the Mauritius result differs, due to a relatively large share of power from off-grid PVs.The remaining objectives of the project, i.e. the completion of two minor country reports and a input data table for AfDB as well as establishing contacts at AfDB, are completed successfully but are not presented in this report. / Detta examensarbete bygger på ett samarbete mellan KTHs avdelning Energisystemanalys, KTH-dESA, och Afrikanska Utvecklingsbanken, AfDB. Arbetet har utförts både från KTH i Stockholm samt på AfDBs tillfälliga huvudkontor i Tunis, Tunisien. Samarbetet mellan KTH-dESA och AfDB är relaterat till tidigare projekt. AfDB har samarbetat med Världsbanken vilket bland annat resulterat i AICD (African Infrastructure Country Diagnostic) som i sin tur skapat programmet AIKP (African Infrastructure Knowledge Program). Liksom i AICD är en viktig del av AIKP att uppskatta infrastrukturinvesteringar kopplade till elsektorn.Syftet med detta examensarbete är att skapa matematiska modeller över elsektorerna i afrikanska länder. Resultaten från dessa ska visa vilka investeringar, eltekniker och bränslen som ger det lägsta totala nuvärdet för respektive land för modelleringsperioden (2010-2030 med fokus på perioden 2014-2020), givet de använda parametrarna. Dessa modeller ska sedan användas för att leverera data till en internetapplikation som AfDB nyligen övertagit från Världsbanken. För att skapa modeller används mjukvaran ANSWER OSeMOSYS, vilket är ett transparant program som är utvecklat för att användas vid systemoptimering som sträcker sig över längre tidsperioder (Howells et al., 2011). Data till modellerna skulle tillhandahållas av AfDB, men då denna inte blev tillgänglig i tid har tillfällig data, delvis tillhandahållen av KTH-dESA, använts. Även antalet undersökta länder har reducerats till fyra, Mauritius, Madagaskar, Egypten och Zimbabwe, istället för de ursprungliga 18 länderna.Modellerna för de fyra länderna blev funktionella, även om resultaten från simuleringarna ännu inte är helt tillförlitliga. Detta då fokus legat på att skapa modeller snarare än resultat, eftersom modellerna i ett senare skede kommer fyllas med ny uppdaterad data från AfDB. I samtliga länder är vatten- och kolkraftverk vanligt förekommande tekniker i resultaten. Egyptens resultat skiljer sig från övriga länders i och med landets stora användning av naturgas i elkonversion. Även Mauritius resultat särskiljer sig genom en relativt stor andel el från decentraliserad PV.Utöver dessa modeller har även en mall för resultatredovisning skapats i form av två mindre rapporter för Mauritius respektive Egypten. Kontakter har även gjorts med olika personer på AfDB för att underlätta för det fortsatta samarbetet mellan KTH-dESA och AfDB.

Mexico is highly dependent on fossil fuels. One of the governmental initiatives proposes to investigate the possibilities for biogas production in rural areas. Agricultural producers are highly susceptible to energy price variations and in most cases the steadily growing prices of electricity and fuels are lowering the profits and income of farmers. Environmental concerns about fossil fuels give additional stimulus towards a switch to more sustainable energy sources. Literature research on different types of biogas production technologies was carried out. Various anaerobic fermentation stages and techniques were studied in order to familiarise with particular features and to understand which of them will be more suitable for locations in rural Mexico, also taking into account the local conditions, availability of raw material, energy demands, etc. Mexico's agricultural policies and governmental support schemes were also studied. The agricultural sector in Mexico is strategically important and brings around 6% of the country's GDP. Security and availability of energy for the rural areas is crucial. A lot of improvements need to be done in this field to make this sector attractive for investors and more profitable for people who already work there. Such governmental organizations as SAGARPA - The Secretariat of Agriculture, Livestock, Rural Development, Fishing, and Food - and its support schemes and programs are aimed to help farmers both financially and technically to overcome the difficulties concerning this procedure. A detailed description of a proposed biogas production plant for a case study project at a milk farm in southern Mexico is presented in this study. Different stages and control strategies of biogas production as well as possibilities for biogas utilization in a small-scale CHP unit are assessed. Economical study was aimed to determine the financial flows of the sample project. A simplified economic analysis showed that the electricity produced in the biogas-driven CHP unit can compete with actual grid electricity prices. In addition, comparatively short payback time could be expected and the available governmental support schemes could be efficiency exploited for a commercially viable biogas production.

In this study, the heat recovery from exhaust gas at the ACE Power Embilipitiya (Pvt) Ltd (APE) in Sri Lanka was conceptually proposed and evaluated. APE has an installed capacity of 100 MW comprising 14 units of 7.5MW medium speed diesel engines fired with heavy fuel oil. There is only a minimum recovery of waste heat in the plant at the moment, only for fuel preheating, whereas waste heat recovery (WHR) boilers of 750kWth are equipped on eight engines. The larger portion of the waste heat is dumped into the environment without being used in any reasonable way. The objective of this work was to design a HRSG system for the remaining six engines to recover maximum possible heat from the exhaust gas and select a suitable steam turbine according to the heat demand capacity of the proposed HRSG, for generating additional power and thus converting the APE plant into a sort of a combined cycle. At the initial stage of the investigation, the amount of recoverable waste heat was estimated by evaluating the known parameters of the engines at fully loaded condition. The maximum theoretical waste heat recovery potential from the exhaust gas stream of one engine was calculated as 9807.87 MJ/h, equivalent to a heat rate of 2724.4 kW. The modelling and optimization of the proposed HRSG was done using the Engineering Equation Solver (EES) software, considering technical and practical limitations such as pinch point temperature difference, approach point temperature difference, terminal temperature difference and sulphur dew point in the stack. A commercially available steam turbine with a power output of 3.579 MW was selected as the optimum steam turbine for the desired conditions, utilising 12884.4 MJ/h of recovered waste energy amounting to 21.89% of the total available energy in the flue gas.

The Republic of Mauritius comprises a main island of an area of 1870km2 at latitude 200 south and longitude 580 east and several outer islands, all of volcanic origin. Mauritius has no known oil, natural gas or coal reserves and is therefore heavily dependent on imported energy sources. In 2012, some 458 ktoe of energy were used for transportation, representing an increase from 391 ktoe in 2009 and 418 ktoe of energy in 2010. The consumption of gasoline increased from 121 ktoe to 128 ktoe (+5.8%) and that of diesel oil from 155 ktoe to 162 ktoe (+4.5%). The consumption of aviation fuel increased from 110 ktoe in 2009 compared to 123 ktoe in 2010 (+11.8%) to 146 ktoe in 2012. In Mauritius the transport sector is the heaviest energy consumer, accounting for 48% of total energy imports and pollution problems in term of vehicular emissions which are more acute in towns where there is heavy vehicular traffic. Mauritius as an island state cannot have the benefit of interconnection facilities and the reliance on fossil fuels can only impact severely on the island in case of crisis In 2006, a comprehensive set of strategies regrouped under the Multi Annual Adaptation Strategy (MAAS) was thus prepared jointly between the Government of Mauritius and the stakeholders in the sugar sector with the objective to investigate the environmental challenges and considerations to produce a comprehensive set of strategies to maintain the commercial viability and sustainability of the sugar sector. The plan that emerged from the MAAS comprised several measures including the transformation of the sugar industry into a sugarcane cluster coupled with the production of a minimum of 30 million litres of ethanol annually. One local ethanol manufacturer is exporting ethanol on regular basis to foreign markets. Export of ethanol has the added advantage of bringing foreign currency to the country and would be encouraged. In line with the Maurice Ile Durable project, to provide with a long-term strategy to progressively reduce the country’s dependence on fossil fuel, the implementation of an ethanol plant in the south of the island, after centralization of the sugar factory activities, has been considered. A case study has been carried out for setting up a 15 million liters dehydrated ethanol plant annexed to the sugar factory.  The cost analysis showed that the annual revenue from the ethanol plant will be $17, 250, 000 and that the payback period will be of 2.9 years. It has been concluded that centralization of sugarcane industry provides with feedstock, with steam and power and minimize transportation costs, thereby increasing the operational and economical cost of ethanol production plant. The amount of molasses that will be produced at each cluster will be some 45 000 tons of molasses and for optimized operating plant, producing more than 20 million liters of dehydrated ethanol, final molasses will have to be outsourced from the other sugar factories on the island.

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One of the drawbacks of the gas turbine is that performance drops rapidly when ambient air temperature increases. This is a major drawback for gas turbines operated in a tropical country like Sri Lanka. In Colombo, commercial capital of Sri Lanka where this study was carried out, the ambient temperature typically varies between 25 0C and 32 0C.   The Kelanitissa gas turbine plant has single shaft gas turbines (GE MS5001 R) operated in open cycle which use diesel as fuel (designed for dual fuel) at a designed heat rate of 13,980 kJ/kWh and an electrical efficiency of 25.8%. The designed exhaust temperature is 513 0C.   In this study, Kelanitissa gas turbine unit was used for assessment of the performance with the changes in ambient air temperature. Two approaches were used to study this phenomenon. Firstly, the performance parameters were calculated by using actual data acquired by the operation history of the power plant. Secondly, the performance was analyzed using thermodynamic principles. Then results of the two approaches were compared.   The present performance values of the studied gas turbine, when compared to designed values, showed a very poor performance due to predominantly high ambient air temperatures. Originally designed for an efficiency of 25.8%, the maximum efficiency achieved at 33 0C was only 21.2%. This translates into a 4.6 %-point reduction in efficiency at 33 0C ambient temperature.   Estimated cooling load for the proposed inlet air cooling is 679.87 RT. Cost per unit cooling load of the reference 2-stage direct-fired absorption system is $751-721 (according to 600RT-700RT). For the worst case scenario the value of $751 per RT and exhaust system constituting 98% of the cost of a market-ready direct fired system (Broad Inc., 2008) can be used. This results in $736/RT as the cost for an absorption chiller system driven by exhaust heat. Total cost for the 679.87 RT system is $ 500,370.72 (Rs. 65Mn).   Payback period of the project is 11 years but the present value after 19 years is exceeding the project cost. Present value for 19 years is Rs. 65.86 Mn. Bringing down the temperature from an average of 270C to the ISO value of 15 0C would give Rs. 6 Mn of annual savings.

The main source of geothermal energy is the heat flow from the mantle beneath the Earth’s surface, generated by the gradual decay of radioactive isotopes in the Earth‘s crust. A hot spring is produced by the emergence of geothermally heated groundwater flowing out to the Earth’s surface. The Chinyunyu hot spring is located about 90km east of Lusaka, Zambia. Water from the spring has been artificially channeled into a large excavated pool which is used as a bathing place. Since the undiluted spring water at the source is too hot for comfortable bathing, it is mixed with surface water to reduce the temperature. There is potential for electricity generation from the Chinyunyu hot spring. Even the most recent proposed survey by the Japanese International Corporation Agency (JICA) in conjunction with the Geological Survey Department in the Ministry of Mines, Energy and Water Development (MMEWD), could not progress beyond the planning stage due to lack of funds. Notable among interest groups in geothermal energy was Kalahari GeoEnergy Limited, a private company registered in Zambia. Even though the objective of Kalahari GeoEnergy Limited was to explore and, if viable, develop geothermal energy resources to produce electrical power in Eastern and Southern Africa, the company concluded that the Chinyunyu Hot Spring was not viable for electricity generation without drilling any test wells and reaching for higher temperatures. The overall purpose of this study is to evaluate the benefits of the current use of the geothermal energy from the Chinyunyu Hot Spring, and also to explore some technically and economically feasible future applications. The study recommends electrical power generation by a binary cycle, with the assumption that drilling for larger mass flow and higher temperatures can be done. Results show that a net power capacity of 233 kWe is technically feasible with minimum environmental impact. However, the expected capital cost in the order of USD 3.4 million and specific cost of $14,500/kWe can hardly be justified without support mechanisms.

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