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The environmental sustainability of biofuel production is still a debated issue in the world bio-economy development. Therefore, different researches are undergoing to evaluate the sustainability of ethanol production in different countries. This study aimed at analyzing the environmental performance of ethanol production in Ethiopia, considering energy balance and emission reduction using a life cycle assessment approach. It is also intended to identify the environmental hotspots so that possible improvement option can be devised. The life cycle assessment methodology was applied considering three alternative scenarios: 1) Base Case, which is the current situation, 2) Alternative 1, which considers the utilization of biogas from vinasse and bioslurry, and 3) Alternative 2, which includes mechanical harvesting and avoids pre-harvest cane trash burning. The results show that agricultural stage is greatly contributing to the pollutant emissions. The contribution of cane trash burning was significant to all the impact categories considered and avoiding pre-harvest cane trash burning significantly reduced the emissions contributing to global warming, acidification, stratospheric ozone depletion, ozone formation, particulate matter and eutrophication. On the other hand, the introduction of mechanical harvesting to avoid pre-harvest cane trash burning increased ecotoxicity, human toxicity and resource consumption (land, water and mineral) impacts. The net energy balance is positive for all the alternatives considered. In addition to using by-products, proper management of fuel utilization at the agricultural stage can further enhance benefits from the sector. Sensitivity analysis revealed that the price of molasses highly influences both energy ratio and greenhouse gas emissions since it completely shifts the allocation of upstream emissions from sugar to molasses.

A literature assessment was conducted to determine the current state of microplastics research in ASEAN countries focusing on 1) microplastics in water, sediment, and water organisms; 2) microplastics' sources and dispersion; and 3) microplastics' environmental consequences, including human toxicity. ASEAN countries contributed only about 5 % of the global scholarly papers on microplastics, with Indonesia contributing the most followed by Malaysia and Thailand. The lack of standard harmonized sampling and processing methodologies made comparisons between research difficult. ASEAN contributes the most to plastic trash ending up in the ocean, indicating a need for more work in this region to prevent plastic pollution. Microplastics are found in every environmental compartment; however, their distribution and environmental consequences have not been sufficiently investigated. There are very few studies on microplastics in the human blood system as well as respiratory organs like the lungs, indicating that more research is needed.

Biomass is one of the most important and emerging sources of energy. The objective of this study was, therefore, to explore the potential of energy production from biomass resources available in Ethiopia. The study involved the estimation of bio-energy potential from crop residues, forest, livestock waste, and municipal solid waste (MSW) in the major towns of the country. The paper also presents policy recommendations for sustainable bio-energy development. The crop, forest, and livestock population data were extracted from the Food and Agriculture Organization statistics database (FAOSTAT) and the country's national and regional reports. The results revealed that Ethiopia has a substantial amount of biomass residues, which are not currently being utilized and collected, that can be used without negatively affecting the socio-economic as well as environmental requirements and without compromising food security. The total bio-energy availability of the country was estimated to be 750 PJ per year (46.5% forest residue, 34% crops residue, 18.8% livestock waste, and 0.05% MSW). The study concludes that an integrated bio-energy database, research development, and identification of feasible bio-energy feedstock value chains are needed to fully realize the potential availability of biomass energy. It also recommends that assessment of the bio-energy value chain should be conducted along its life cycle.

Ethiopia is one of the fastest growing countries in the world with a 10.9% GDP growth rate in 2017. This high growth cannot be sustained without the deployment of modern energy in its different forms. To this end, the government is approaching the production of different types of modern and renewable energy. Among the renewable energy, molasses ethanol is the one given attention. This piece of research is aimed at evaluating the sustainability of molasses ethanol production and consumption considering gasoline substitution potential and eco-efficiency. The results show that achieving a 10% molasses-based ethanol blend with gasoline (E10) throughout the country is difficult even with production at full capacity of the existing factories. To achieve E10, 76.2 million liter annual production of ethanol is required, while the current production potential is only 20 million liter. The ambitious government plan of E15 by 2020 can only be achieved by 2025 if all the plants under construction are operational by 2025 and can operate at full capacity. If the plan is achieved, 31.85, 74.5 and 159 million USD can be saved yearly from the E10, E15 and E20 mandates, respectively. Using the byproducts as much as possible within the ethanol-processing framework significantly increases the eco-efficiency (40%) of the products.

Household cooking is a major energy intensive activity in most of the Ethiopian households. Replacing the existing inefficient cooking stoves and the polluting energy source with a renewable source of energy plays a paramount role in conserving the environment and reducing the indoor pollution. In this study an energy storage phase change material is proposed to store solar thermal energy for a potential household cooking application. The selected phase change material has a melting point range which is well fitted to the operating range of temperatures for most of the household cooking activities. The solar energy source is simulated with electrical heating for experimental investigation of the thermal characteristics. Also it is intended to study the thermal characteristics of the mixture using deferential scanning calorimeter to identify at which mass ratio the mixture shows better thermal characteristics. From the laboratory analysis it is found that the 60% NaNO3 and 40% KNO3 by mass have shown promising thermal characteristics. For applying the selected salt mixture for cooking application, an experiment was conducted on two Ethiopian local meals, shiro wet and potato meal, to know how much energy is required to cook them and what amount of the PCM is required to store the required energy. The result reveals that 2.38 kWh energy is required for cooking the two meals for five family members for lunch and dinner. To store the energy required 4 kg of the PCM was required. Experiments were conducted to see the charging and discharging time of 60% NaNO3 and 40% KNO3 by mass. From the experimental result for 1.4 kg of the PCM, charging time of 50 minutes up to 300°C and a discharging time of 4.5 hours (from 300°C to 100°C) are required.