Viability of non-edible oilseed plants and agricultural wastes as feedstock for biofuels production: A techno-economic review from an African perspective

This research articles was published in Journals Biofuels Bioproducts& Biorefining Volume 17, Issue 5,2023Given the benefits of biofuels over conventional fuels, there is concern that widespread production of biofuels from edible feedstocks to meet demand will lead to food insecurity and other socioeconomic challenges. Thus, the goal of this research is to look into the techno-economic potential of non-edible oilseed plants and agricultural wastes as primary feedstocks for biofuel production in Africa. The inability of biofuel to cope in the fuel market has been demonstrated to be due to the high production costs, which limit profitability because the end price is heavily influenced by that of conventional fuel. However, the high production costs are entirely due not only to components such as feedstock, conversion processes, and infrastructure but also to a lack of techno-economic assessment (TEA). African biofuel production can be competitively industrialized through the adoption of strong supportive policies and programs. Adoption of these policies and programs is critical for capitalizing on the benefits of non-edible feedstocks in biofuel production while also boosting rural development through job creation. Techno-economic assessment of conversion processes and infrastructure is recommended to provide a clear picture of the techno-economic aspects, serving as a blueprint for the design of biofuel production facilities. Further, TEA has been shown to be a useful tool in the development process of new technologies aimed at lowering overall production costs and making biofuel more affordable. The combination of TEA and enabling policies and programs will increase the price competitiveness of biofuels, allowing them to capture a sizable share of the fuel market. © 2023 Society of Industrial Chemistry and John Wiley & Sons Ltd

Comprehensive assessment of heat pump dryers for drying agricultural products

This research article was published by Wiley Online Library, 2022Fruits and vegetables are agricultural products that require preservation to enhance and protect shelf life, encapsulate natural flavour, and retain nutritional content. Globally, agricultural products are preserved by a range of means, the most prevalent of which is the heat pump dryer, which produces the best results even in unfavourable climatic conditions. Heat pump dryers come in different types and their performance varies depending on the type. This study aims to evaluate recently developed heat pump dryers based on key performance indicators, impacts on food colour and nutritional content, techno-economic, exergoeconomic, and environmental issues associated with the development of heat pump dryers, which are underrepresented in most of the existing heat pump dryers' reviews. This study also discusses mathematical drying kinetic models, and regulation or policy aspects related to the development of heat pump dryers. In the present study, the results on performance analysis indicate that heat pump dryers examined were effective in reducing drying time and obtaining high coefficients of performance ranging from 1.94 to 5.338 and specific moisture extraction rate ranging from 0.156 to 9.25 kg/kWh, as well as significantly reducing energy consumption by up to 80%. The nutritional composition and colour results show that heat pump dryers maintain the maximum nutrient content while also improving colour. The expansion valve has the lowest exergoeconomic factor of all heat pump dryer components, whereas the compressor has the highest cost of exergy destruction in general, according to the results of exergoeconomic analysis. Techno-economic analysis results demonstrated that most developed heat pump dryers have short payback periods ranging from 1.6 to 3.6 years. However, due to a lack of research in this field, the environmental implications of heat pump dryers are unknown. As per the findings of this study, future research in this field should focus on the design of simple and low-energy heat pump dryers, life cycle, techno-economic, and exergoeconomic assessments

Modelling of Future Energy Demand for Tanzania

This paper present modelling of long-term energy demand forecast in the main economic sectors of Tanzania. The forecast of energy demand for all economic sectors is analyzed by using the Model for Analysis of Energy Demand (MAED) for a study period from 2010-2040. In the study three scenarios namely business as usual (BAU), low economic consumption (LEC) and high economic consumption scenario (HEC)  were formulated to simulate possible future long-term energy demand based on socio-economic and technological development with the base year of 2010. Results from all scenario suggests an increased energy demand in consuming sectors with biomass being a dominant energy form in service and household sectors in a study period. Predicted energy demand is projected to increase at a growth rate of 4.1% and reach 74 MTOE in 2040 under BAU scenario. The growth rates for LEC and HEC are projected at 3.5% and 5.1% reaching 62 MTOE and 91 MTOE in 2040 respectively. Electricity demand increases at a rate of 8.5% to reach 4236 kTOE in 2040 under BAU scenario while electricity demand under LEC and HEC increases to 3693 kTOE and 5534 kTOE in 2040 respectively. Sectrorial predicted demand results under both scenarios determines high demand of biomass for service and household sectors with decreasing demand of biomass in industry sector. Transport sectors predicted energy demand pattern suggests an increased demand in passenger transport than freight transport in both scenarios. Final energy demand per capita in both scenario show an increased trend with lower growth in LEC scenario while there is a decrease in energy intensity throughout study period. Key Words: MAED, energy demand, energy demand forecasting, energy demand modellin

Modelling energy supply options for electricity generations in Tanzania

The current study applies an energy-system model to explore energy supply options in meeting Tanzania’s electricity demands projection from 2010 to 2040. Three economic scenarios namely; business as usual (BAU), low economic consumption scenario (LEC) and high economic growth scenario (HEC) were developed for modelling purposes. Moreover, the study develops a dry weather scenario to explore how the country’s electricity system would behave under dry weather conditions. The model results suggests: If projected final electricity demand increases as anticipated in BAU, LEC and HEC scenarios, the total installed capacity will expand at 9.05%, 8.46% and 9.8% respectively from the base value of 804.2MW. Correspondingly, the model results depict dominance of hydro, coal, natural gas and geothermal as least-cost energy supply options for electricity generation in all scenarios. The alternative dry weather scenario formulated to study electricity system behaviour under uncertain weather conditions suggested a shift of energy supply option to coal and natural gas (NG) dominance replacing hydro energy. The least cost optimization results further depict an insignificant contribution of renewable energy technologies in terms of solar thermal, wind and solar PV into the total generation shares. With that regard, the renewable energy penetration policy option (REPP), as an alternative scenario suggests the importance of policy options that favour renewable energy technologies inclusion in electricity generation. Sensitivity analysis on the discount rate to approximate the influence of discount rate on the future pattern of electricity generation capacity demonstrated that lower values favour wind and coal fired power plants, while higher values favour the NG technologies. Finally, the modelling results conclude the self-sufficiency of the country in generating future electricity using its own energy resources

Modelling energy supply options for electricity generations in Tanzania

The current study applies an energy-system model to explore energy supply options in meeting Tanzania’s electricity demands projection from 2010 to 2040. Three economic scenarios namely; business as usual (BAU), low economic consumption scenario (LEC) and high economic growth scenario (HEC) were developed for modelling purposes. Moreover, the study develops a dry weather scenario to explore how the country’s electricity system would behave under dry weather conditions. The model results suggests: If projected final electricity demand increases as anticipated in BAU, LEC and HEC scenarios, the total installed capacity will expand at 9.05%, 8.46% and 9.8% respectively from the base value of 804.2MW. Correspondingly, the model results depict dominance of hydro, coal, natural gas and geothermal as least-cost energy supply options for electricity generation in all scenarios. The alternative dry weather scenario formulated to study electricity system behaviour under uncertain weather conditions suggested a shift of energy supply option to coal and natural gas (NG) dominance replacing hydro energy. The least cost optimization results further depict an insignificant contribution of renewable energy technologies in terms of solar thermal, wind and solar PV into the total generation shares. With that regard, the renewable energy penetration policy option (REPP), as an alternative scenario suggests the importance of policy options that favour renewable energy technologies inclusion in electricity generation. Sensitivity analysis on the discount rate to approximate the influence of discount rate on the future pattern of electricity generation capacity demonstrated that lower values favour wind and coal fired power plants, while higher values favour the NG technologies. Finally, the modelling results conclude the self-sufficiency of the country in generating future electricity using its own energy resources

Modelling of energy demand and supply patterns in Tanzania

A Dissertation Submitted in Partial Fulfilment of the Requirements for the Degree of Doctor of Philosophy in Sustainable Energy Science and Engineering of the Nelson Mandela African Institution of Science and Technology.Energy is an important element in realizing the interrelated socio-economic development of countries. In an attempt to develop long term energy demand and supply patterns that would enable the country meet her growing energy demand sustainably using the current and future available energy resources, a study of its own kind was carried out. The analysis of the influential indicators in the determination of energy demand based on the selected socio-economic and environment indicators preceded the study. Artificial neural network-multilayer perceptron (ANN-MLP), multiple linear regression (MLR), and support vector machine for regression (SVR) techniques were employed in the analysis. The findings depicts a strong relationship between energy indicators and energy demand for Tanzania. The energy indicators model showed greater accuracy in the prediction of energy demand as compared to economic and environment indicators models. ANN-MLP, MLR and SVR techniques reached satisfactory prediction results though ANN-MLP produced the most accurate predictions. The long-term energy demand simulation for a study period 2010-2040 was done using the Model for Analysis of Energy Demand (MAED). The simulation involved case study scenarios to mimic possible future long-term energy demand based on socio-economic and technological development. Simulated results suggest an exponential growth of the total final energy demand with electricity demand shift from household dominance towards industry and service sectors describing changes in the lifestyles. Nevertheless, the electricity demand growth rate has been shown to be greater than that of energy demand describing more mechanisation in the industry and service sectors. Final energy demands per capita shows an increasing tendency while there is a decrease in energy intensity suggesting energy efficient measures. Long-term energisation plan was achieved through a bottom-up modelling approach using Model for Energy Supply Strategy Alternatives and their General Environmental Impacts (MESSAGE). Least-cost results showed dominance of hydro, coal, geothermal and natural gas as possible supply options for future electricity generation. Though these energy resources are locally available and give least-cost advantages, their combinations is heavily skewed to the non-environmental friendly resources. Optimised results indicate, without interventions in promoting renewable energy, its influence in power generation will remain insignificant and therefore recommends policies ii formulations to ensure significant contribution. Finally, the results have established that it is feasible to have a sustainable and economical supply of energy for Tanzania that will meet her energy demand and ensure an optimized option for short, medium and long term energisation plans using currently available energy resources

The Status and Future Prospects of Hydropower for Sustainable Water and Energy Development in Tanzania

Tanzania is among the countries with the fastest growing economy in Africa and therefore the need for affordable, clean, and most importantly sustainable electrical energy to meet her ever growing demands is pressing. In recent years, the country’s electricity needs have been largely dominated by thermal generations despite the fact that Tanzania is gifted with huge hydropower resource potential approximated at 38,000 MW with only a very small portion exploited to date. However, the exploited potential is expected to grow by commissioning of identified large and medium-scale hydropower projects with a total installed capacity of 4,765 MW currently under various stages of implementation. Moreover, the geographical location of Tanzania has several benefits to support development of small hydropower projects essential for appropriate utilization of available water resources as a way of mitigating climate challenges effects. Over the last decade, the country electricity demand along with end-use of energy has witnessed significant increases as economic development spreads towards achieving Vision 2025 goals. Proposed hydropower developments are projected to have enormous benefits in the acceleration of economic growth while contributing to greenhouse gas emissions reduction. In this paper, hydropower, which is one of the domestic options for clean energy development path, its present and future potential status, and water resources are explored based on a comprehensive review of energy sector relevant documents and polices

The Potential of Underutilized Plant Resources and Agricultural Wastes for Enhancing Biodiesel Stability: The Role of Phenolic- Rich Natural Antioxidants

This research articles was published in Journals International Journal of Energy Research Volume,2023Growing concerns about energy security and environmental sustainability have fueled demand for sustainable and renewable energy sources in recent years. Biodiesel, a renewable alternative to conventional fuels, has gained significant attention as a potential source of energy. However, the stability of biodiesel during storage and its susceptibility to oxidation remain major challenges. To address these issues, researchers have turned their focus to the utilization of natural antioxidants. Studies on sources of natural antioxidants, particularly those made from waste, such as food, have been extensively conducted. However, there are still some restrictions, such as inconsistency in quality, the development of microbes, and difficulties with regulations, all of which have an impact on sustainability and the phenolic contents. Phenolic compounds are known for their excellent antioxidant properties and ability to inhibit the oxidation process. The review provides an overview of various underutilized plant resources and agricultural wastes that are rich in phenolic contents and demonstrate higher antioxidant activities, such as Vitex doniana, Uapaca kirkiana, Parinari curatellifolia, Tamarindus indica L, fruit peels, and crop residues. It discusses the extraction methods employed to obtain phenolic antioxidants from these sources and highlights their antioxidant activities. Additionally, the review examines the effects of phenolic antioxidants on key parameters, including induction period, peroxide value, acid value, and viscosity. The review concluded by highlighting the potential of underutilized plant resources and agricultural wastes as sustainable sources of phenolic-rich natural antioxidants for enhancing biodiesel stability. According to the literatures, phenolic antioxidants present in underutilized plant resources and agricultural wastes can chelate metal ions, scavenge free radicals, and break oxidation chain reactions, thereby preventing the degradation of biodiesel. Moreover, the limitation of the use of natural antioxidants in the stabilization of biodiesel like instability at high temperatures has been highlighte

Semi-Transparent Building Integrated Photovoltaic Solar Glazing: Investigations of Electrical and Optical Performances for Window Applications in Tropical Region

This research article published by Hindawi, 2019Integrating solar PV technology with semi-transparent windows permits multifunctional operation as electricity generation and allowing natural light to enter the building, hence overall energy efficiency improvement. The performance of the semi-transparent building integrated PV glazing on office building facade has been investigated in Tanzania’s tropical climate. Experimental measurements of the electrical and optical parameters for the system efficacy evaluation were done at various conditions which included cloudy, normal, and clear sky days. The weather parameters under consideration were solar irradiance, air temperature, relative humidity, and wind speed. The experimental set-up consisted of building integrated silicon mono crystalline semi-transparent PV module rated at 50 W and accessories. The I-V and P-V curves were measured at different irradiances. Throughout the experiment, the observed module temperature was between 20°C and 51°C and the air temperature was 17–33°C while the humidity was recorded at the range of 23–63%. Module electrical efficiency was observed to vary from 4% to 9% while the visible light transmission was obtained between 11% and 19%. It was proved that at high temperature regardless of irradiance increase, there were observed output power and efficiency drops caused by high heat losses