Abstract: Plastics are cheap, lightweight, and durable and can be easily molded into many different products, shapes, and sizes, hence their wide applications globally, leading to increased production and use. Plastic consumption and production have been growing since its first production in the 1950s. About 4% of global oil and gas production is being used as feedstock for plastics, and 3–4% is used to provide energy for their manufacture. Plastics have a wide range of applications because they are versatile and relatively cheap. This study presents an in-depth analysis of plastic solid waste (PSW). Plastic wastes can be technically used for oil production because the calorific value of the plastics is quite comparable to that of oil, making this option an attractive alternative. Oil can be produced from plastic wastes via thermal degradation and catalytic degradation, while gasification can be used to produce syngas. Plastic pyrolysis can be used to address the twin problem of plastic waste disposal and depletion of fossil fuel reserves. The demand for plastics has continued to rise since their first production in the 1950s due to their multipurpose, lightness, inexpensiveness, and durable nature. There are four main avenues available for plastic solid waste treatment, namely, reextrusion as a primary treatment, mechanical treatment as secondary measures, chemical treatment as a tertiary measure, and energy recovery as a quaternary measure. The pyrolysis oil has properties that are close to clean fuel and is, therefore, a substitute to fresh fossil fuel for power generation, transport, and other applications. The study showed that plastic wastes pyrolysis offers an alternative avenue for plastic waste disposal and an alternative source of fossil fuel to reduce the total demand of virgin oil. Through plastic pyrolysis, plastic wastes are thermally converted to fuel by degrading long-chain polymers into small complex molecules in the absence of oxygen, making it a technically and economically feasible process for waste plastic recycling. The process is advantageous because presorting is not required, and the plastic waste can be directly fed without pretreatment prior to the process. Products of plastic pyrolysis are pyrolysis oil, a hydrocarbon-rich gas, with a heating value of 25–45 MJ/kg, which makes it ideal for process energy recovery. Hence, the pyrolysis gas can be fed back to the process to extract the energy for the process-heating purpose, which substantially reduces the reliance on external heating sources. PubDate: Mon, 22 May 2023 11:20:01 +000
Abstract: Sugar industries have huge potential to contribute to the sustainable energy transition through electricity generation and production of biofuels. Sugar-producing countries generate huge volumes of sugarcane bagasse as a byproduct of sugarcane production. In this study, the performance of an operating traditional sugar factory is analyzed for electricity generation and export potential. The study presents characteristics and energy potential of modern and traditional sugar factories. The challenges facing a traditional sugar mill are inefficient boilers, less efficient and back pressure steam turbines, and wasteful and inefficient use of steam turbine drives as prime movers instead of modern electric drives for the mills and cane knives. Others are the use of inefficient and energy intensive cane mill rollers instead of the diffusers which have low energy requirements. It was demonstrated that the cogeneration potential of sugar factory is quite significant but currently underutilized. Sugar factories can make significant contribution towards mitigation of greenhouse gas emission mitigation through supply of green electricity to the public grid. The study showed that the factory uses very old and inefficient boilers aged over 39 years which contributes to poor performance and low electricity generation capacity. Modernization is required to increase the generation and electricity export capacity through investment in new and modern high-pressure boilers, replacement of inefficient back pressure boilers (BPSB) with more efficient condensing extraction turbines (CEST), and reduction of factory steam consumption by electrification of mills and cane knife turbine drives among other measures. This study showed that the 3,000 TCD factory can invest in a 15 MW power plant based on current average factory performance indicators and more if the throughput and overall performance is close to design parameters. PubDate: Fri, 19 May 2023 10:50:01 +000
Abstract: Procyclicality has been discovered in crude oil price shocks on aggregate demand. Most studies have used linear estimation techniques, resulting in the loss of asymmetric correlations. We disaggregate the impact of changes in oil prices into positive and negative shocks on aggregate demand and its components from 1970 to 2015 using the nonlinear ARDL framework. The results show that oil price shocks in Ghana have a long-term beneficial asymmetric impact on aggregate demand and its components. Specifically, a positive change in oil price (0.230) has a greater positive effect on the aggregate demand than a negative effect (-0.009) emanating from a negative change in the oil price shock. Further, the same result was obtained for the components of the aggregate demand with the impact on investment expenditures (0.662) being the greatest. Policymakers should diversify energy demand according to our recommendations. Instead of exporting crude oil, officials should encourage its refinement and consumption. Lastly, we suggest that policymakers hedge and use price-smoothing strategies to reduce oil price volatility. PubDate: Thu, 11 May 2023 07:20:01 +000
Abstract: Green energy is the primary concern for the sustainable development of Ethiopia’s Afar region. The study’s goals are to present scientific evidence of the Afar region’s energy potential to researchers and industry sectors. We used solar shortwave, radiation transfer model, miniscale meteorological model for the Weather Research Forecast (WRF), and spatial and temporal simulation as research techniques. The data show that the Afar region has an energy potential of 239.9 W/m2 average solar radiation flux, 2.102 MW·h/m2 average annual solar density, 131.18 W/m2 average wind power density at , and 204.5 W/m2 average wind power density at . We discovered that solar energy and wind energy are potential energy sources in the Afar region for energy consumption such as solar cooking, solar lighting, and small DC applications. PubDate: Fri, 24 Mar 2023 10:20:01 +000
Abstract: Ghana is experiencing an increase in energy demand as a result of increased industrialization activities. Nonrenewable energy sources, such as combustible fuels like petroleum, are the primary source of energy. Nonrenewable energy resources are associated with a number of issues, including environmental pollution. Renewable energy is a sustainable source of energy that is critical to the energy sector and the economy’s progress. Hydropower, biomass, solar energy, and wind energy are among the renewable energy resources available in Ghana. In Ghana, key institutions are responsible for the management and development of energy sources in the renewable energy sector. Among these institutions is the Ministry of Energy, which is responsible for the formulation and implementation of laws and policies, for instance, the Renewable Energy Act of 2011. Volta River Authority (VRA), Ghana Grid Company (GGC), and Electricity Company of Ghana (ECG) are among the institutions under the Ministry of Energy. There are also regulatory agencies established by parliamentary act to ensure that all actors in the sector are working properly. Among these are the Energy Commission, the Public Utilities Regulatory Commission (PUR), and the National Petroleum Authority. Active nongovernmental organisations (NGOs), research institutes and universities, and industry are also involved in renewable energy activities. PubDate: Wed, 18 Jan 2023 13:05:02 +000
Abstract: The actuator-cylinder RANS (Reynolds-averaged Navier-Stokes equations) model was used to study the performance of two different arrays of wind turbines. The staggered array proved to be more efficient than the fish-school array (grouped in pairs) in most directions; however, the fish-school array outperformed the conventional staggered array when the pairs of turbines were facing the wind. Increases in global power coefficient up to 16% were found when the wind speed was 8 ms-1 and up to 10% when the wind speed was 10 ms-1. Despite the fish-school array being slightly less efficient, this array yielded almost twice as much power density as the staggered array in almost all directions. The current methodology proves to be a fast tool for the estimation of vertical-axis wind turbine farms compared to full RANS simulations. PubDate: Wed, 21 Dec 2022 06:50:01 +000
Abstract: Globally, biogas technology has been touted by academics, international organizations, United Nations, and pressure groups, among others, as an effective tool for protecting the planet against degradation. As such, stakeholders in the biogas technology sector have made some policy recommendations toward that goal. These include a global campaign in support of energy for sustainable development, climate financing by the international community, all countries adopting appropriate national strategies, innovative financial mechanisms, and encouraging private-sector participation in achieving the goal. Clearly, for countries to promote accessibility and create favorable perceptions on the adoption of biogas technology requires institutional involvement and collaboration. That is, institutions need to participate and contribute in terms of ideas and expertise as well as work together to ensure the dissemination and uptake of biogas technology in Ghana. This study is aimed at assessing the level of institutional involvement and collaboration and barriers to biogas technology dissemination in Ghana. A qualitative method was employed, and data were collected from 101 respondents through interviewing. The results indicated that the involvement of government and financial institutions in disseminating biogas technology was low, while biogas service providers showed moderate involvement. With regard to collaboration, it was revealed that institutions moderately collaborate in awareness creation but had low collaborations for promotion, monitoring, and evaluation. Furthermore, the lack of a national biogas policy, low government commitment towards biogas technology, and low financial support were key barriers to effective institutional involvement and collaboration in disseminating biogas technology in Ghana. It is recommended that the government shows a high commitment by providing the needed resources for dissemination activities and task the Ghana Energy Commission to formulate a national biogas policy to facilitate dissemination and adoption. Finally, a national biogas steering committee composed of all relevant stakeholders, including the Finance Minister or a representative from the Finance Ministry would create a good platform to help champion the dissemination of biogas technology in Ghana. PubDate: Mon, 21 Nov 2022 07:35:04 +000
Abstract: This work estimates the annual energy that could be generated from a concentrated solar power (CSP) plant. The optimal location used for this analysis was selected based on a set of multicriteria decision-making (MCDM) methods employed in an earlier research. The paper also determines the financial viability of implementing a CSP plant within the selected location. A 100 MW CSP plant for the said location was modelled and simulated using the System Advisor Model (SAM) software with data from the online database of the National Renewable Energy Lab (NREL) available from the SAM software. Using a solar multiple of 2.0 with a TES of 6 hours, the plant generated an estimated annual energy of 306.850 GWh with a capacity factor of 35.10% and gross-to-net conversion of 89.10%. The months with the highest generation were from November to March while July to September had the least generation. Generation begins from 8 am, rising to a peak around 12 pm to 4 pm and gradually declines into the night. Results from the financial analysis produced a net present value (NPV) of USD 156,287,433.72 after the plant life of 25 years, indicating profitability of the project. Results from the sensitivity analysis showed that the project NPV became negative only when the base case capital cost, electricity price, and revenue were, respectively, increased by 15%, reduced by 10%, and reduced by 13%. PubDate: Tue, 08 Nov 2022 01:35:01 +000
Abstract: Wind power is one of the most efficient, reliable, and affordable renewable energy sources. The Doubly Fed Induction Generator (DFIG) is the most commonly used machine in wind power systems due to its small size power converter, reduced cost and losses, better quality, and the ability for independent power control. This research work deals with the power control of this machine by modeling and designing a suitable controller. Vector control is used to control the stator and grid active and reactive powers along with the proportional integral (PI) controller, fuzzy logic controller (FLC), and PI-fuzzy controllers. Modeling and simulation of the system are done using MATLAB Simulink, and the behavior of the machine with each controller is examined under variable wind speeds. Comparative analysis based on reference power tracking, stability, and grid code requirement fulfillment has been conducted. The obtained results show that among the three controllers, the PI-fuzzy controller meets the required specification with better performance, small oscillation, minimum overshoot, better reference tracking ability, and creating a stable and secure system by fulfilling grid code requirements. This study can be important to further insight into DFIG-based wind turbine systems. PubDate: Mon, 07 Nov 2022 02:35:01 +000
Abstract: Gadam sorghum stalks are agricultural residues which can be hydrolyzed into fermentable sugars that can be used to produce bioethanol which is a renewable source of energy. In order to produce bioethanol from lignocellulosic biomass such as Gadam sorghum stalks, several processes including hydrolysis are involved. However, the use of lignocellulosic biomass for bioethanol production is hindered by the low yield of fermentable sugars obtained during hydrolysis. The lack of sufficient information on optimal conditions governing hydrolysis of lignocellulosic biomass leads to inefficient process which hinders the economic viability of large-scale bioethanol production. The objective of this study was to optimize reaction conditions involved in concentrated sulphuric acid hydrolysis of Gadam sorghum stalks. During hydrolysis, the conditions that were varied included temperature (40°C–80°C), time (30-90 minutes), and concentration of acid (30%-70%, ). Central composite rotatable design was used to optimize and establish optimum level of hydrolysis conditions. Response surface methodology and analysis of variance were used to interprete the results. The results of hydrolysis revealed that the highest yield of glucose was 87.54% () which was realized at 60°C hydrolysis temperature, 60 minutes hydrolysis period, and 50% () concentration of sulphuric acid. In addition, the lowest glucose yield was 45.59% () which was realized at 60°C hydrolysis temperature, 60 minutes hydrolysis period, and 16.36% () sulphuric acid concentration. Concentrated sulphuric acid hydrolysis of Gadam sorghum stalks results in high yield of fermentable sugars. These results reveal that Gadam sorghum stalks are viable substrates for the production of fermentable sugars. PubDate: Sat, 08 Oct 2022 06:50:01 +000
Abstract: Pure electric vehicles provide an enticing ecofriendly alternative to traditional fossil fuel combustion engine locomotives. Batteries have primarily been used to store energy in electric vehicles; however, peak load demand and transient power leading to decreased battery lifespan have bred interest in hybrid energy storage systems in electric vehicles. Management of energy drawn from a hybrid energy storage system (HESS) in electric vehicles is a real-time multistage optimization problem aimed at minimizing energy consumption while aptly distributing energy drawn from the battery and capacitor to enhance the battery life cycle. This paper explores the feasibility of a master-slave salp swarm optimization algorithm (MSSSA) (metaheuristic algorithm) in a HESS control strategy for electric vehicles. Introducing a master-slave learning approach to the salp swarm algorithm (SSA) improves its performance by increasing its convergence rate while maintaining a balance between exploration and exploitation phases of the algorithm. A comparison of the MSSSA results with the SSA (salp swarm algorithm), DA (dynamic algorithm), WOA (whale optimization algorithm), MFO (moth flame optimization algorithm), GA (genetic algorithm), and PSO (particle swarm optimization algorithm) on benchmark test functions and dynamic program simulation of an electric vehicle’s HESS control strategy and shows preeminence of the MSSSA control strategy for HESS. PubDate: Wed, 14 Sep 2022 08:35:01 +000
Abstract: As a development method to replace steam stimulation of heavy oil, in situ combustion often faces many problems in thick reservoir, such as low vertical sweep efficiency and channeling combustion. According to the characteristics and development history of this kind of reservoir, a method of changing plane fire flooding to gravity fire flooding is proposed by using the existing steam stimulation development well pattern and sidetracking horizontal section of vertical production wells. The influence of different factors on sidetracking gravity fire flooding production effect is analyzed from the aspects of reservoir geology and development engineering. The internal stimulation mechanism of this method is further studied, and the evaluation model between recovery factor and main control factor is established by using multiple linear regression equation. The results show that vertical sidetracking gravity fire flooding can improve the recovery of thick heavy oil reservoir by 42%; the better recovery effect can be obtained when the sidetracking length is about 1/2 of the well spacing; the coincidence degree between the established recovery evaluation model and the results of numerical simulation is more than 85%. The research results of this paper can help the mine fire flooding development to change the mining mode and provide some guidance for the medium- and long-term planning. PubDate: Mon, 05 Sep 2022 14:05:02 +000
Abstract: Biogas is competitive, viable, and generally a sustainable energy resource due to abundant supply of cheap feedstocks and availability of a wide range of biogas applications in heating, power generation, fuel, and raw materials for further processing and production of sustainable chemicals including hydrogen, and carbon dioxide and biofuels. The capacity of biogas based power has been growing rapidly for the past decade with global biogas based electricity generation capacity increasing from 65 GW in 2010 to 120 GW in 2019 representing a 90% growth. This study presents the pathways for use of biogas in the energy transition by application in power generation and production of fuels. Diesel engines, petrol or gasoline engines, turbines, microturbines, and Stirling engines offer feasible options for biogas to electricity production as prme movers. Biogas fuel can be used in both spark ignition (petrol) and compression ignition engines (diesel) with varying degrees of modifications on conventional internal combustion engines. In internal combustion engines, the dual-fuel mode can be used with little or no modification compared to full engine conversion to gas engines which may require major modifications. Biogas can also be used in fuel cells for direct conversion to electricity and raw material for hydrogen and transport fuel production which is a significant pathway to sustainable energy development. Enriched biogas or biomethane can be containerized or injected to gas supply mains for use as renewable natural gas. Biogas can be used directly for cooking and lighting as well as for power generation and for production of Fischer-Tropsch (FT) fuels. Upgraded biogas/biomethane which can also be used to process methanol fuel. Compressed biogas (CBG) and liquid biogas (LBG) can be reversibly made from biomethane for various direct and indirect applications as fuels for transport and power generation. Biogas can be used in processes like combined heat and power generation from biogas (CHP), trigeneration, and compression to Bio-CNG and bio-LPG for cleaned biogas/biomethane. Fuels are manufactured from biogas by cleaning, and purification before reforming to syngas, and partial oxidation to produce methanol which can be used to make gasoline. Syngas is used in production of alcohols, jet fuels, diesel, and gasoline through the Fischer-Tropsch process. PubDate: Sat, 09 Jul 2022 07:50:03 +000
Abstract: Energy supply is a critical indicator for the global United Nations initiatives because of its immense contribution to economic development. In essence, identifying the required energy resource coupled with effective policy strategies is essential to sustainable electricity generation. Nevertheless, future electricity supply requires a range of options that must be robust and workable. Globally, the challenge of harnessing the energy resources sustainably needed for effective electricity generation is alarming. Therefore, the ability to supply a country’s electricity based on the availability and affordability of resources is vital for effective governance. In this study, Ghana’s energy resourcefulness and the profound effects on the future mix of electricity generation are qualitatively reviewed. In particular, the study covers the existing and potential energy resources available for sustainable electricity generation. The study revealed that Ghana mainly uses hydro, natural gas, and solar energy, among others, for electricity generation. Additionally, a framework explores a well-diversified generation mix using nuclear, coal, and more renewable energy sources in the long-term. Key issues that emerged for national consideration include the need for effective policy direction and implementation, appropriate financing concepts, fuel availability, political will, and setting. By far, this review sought to emphasize literature gaps by providing a rich and fertile ground as a template for industry operators, policymakers, and future research direction. PubDate: Wed, 25 May 2022 09:05:02 +000
Abstract: The pursuit of middle-income economic status by Ghana comes with an associated increase in electricity and energy demand. Meanwhile, an increase in either electricity or energy consumption is likely to result in greenhouse gas (GHG) emissions as a result of increasing reliance on fossil fuel consumption. Presently, there is evidence of the impact of climate change on various aspects of Ghana’s socio-economic structures such as energy production, agriculture, and forestry. Therefore, it is imperative to develop and implement a long-term low-carbon sustainable energy supply strategy that will support the electricity demand of the major economic ambitions envisaged. This study applied a quantitative modelling and simulation methodology using the Model for Energy Supply Strategy and their General Environmental Impacts (MESSAGE) analytical tool to analyse the electricity generation system and the impact of fuel options on the environment. It was found that the inclusion of low-carbon emission energy conversion technologies such as renewables and nuclear energy is critical to curtailing carbon dioxide (CO2) emissions in Ghana’s energy sector. Therefore, the incorporation of climate-friendly energy sources into the electricity sector is necessary to achieve sustainable, resilient, and clean electricity generation. Ghana’s fulfilment of its international commitment to climate change depends on reducing its dependence on fossil fuels for electricity generation, thus, exploring the inclusion of zero-emitting sources into the country’s energy mix. PubDate: Tue, 26 Apr 2022 04:35:00 +000
Abstract: In Ethiopia, in addition to the large quantity of biomass consumption per year for daily cooking, production of the traditional local “Areke” consumes large amounts of fire wood which further accelerates deforestation. This study introduces solar-based technology for distillation of the local “Areke” using an indirect heating system. A solar parabolic dish collector with an aperture diameter of 0.9 m and an improved truncated cone cavity absorber were installed. The heat transfer process is governed by the principle of natural circulation, boiling, and condensation between a receiver and a distillation column. The experiment was conducted in Debre Birhan city at 20°C ambient temperature and atmospheric pressure of 0.722 atm. The surface temperature of the truncated cone cavity absorber attained a maximum temperature of 300.3°C, and the thermal efficiency attained by the collector was 54.6%. The production efficiency of the solar thermal local alcohol “Areke” distillation system was found to increase by 1.67% compared to the traditional firewood distillation system. PubDate: Mon, 11 Apr 2022 09:05:02 +000
Abstract: Proper management and effective conversion of biomass residues for biofuel production are crucial to reduce deforestation due to the cutting of trees for cooking and heating as a primary source of fuel and improving energy utilization of households. Thus, this study is aimed at investigating the effects of biomass residues of the coffee husk (CH), sawdust (SD), khat waste (KW), and dry grass (DG) and binding materials prepared from the waste paper pulp (PP) and clay soil (CS) under a low-pressure piston press densification machine. The biomass waste and binders were combined in a 3 : 1 ratio of CH : PP, CH : CS, SD : PP, SD : CS, KW : PP, KW : CS, DG : PP, and DG : CS. The briquettes were produced using a manually operated closed-end piston press machine compacted at an average pressure of 2 MPa. Briquette proximate and ultimate analysis of moisture content, volatile matter, fixed carbon, and ash content was determined using standard ASTM methods, while the calorific value was determined using a bomb calorimeter and data analysis was carried out using the R-program. Results revealed that the briquette produced from biomass residues has a mean value of fixed carbon and calorific value that ranged from to and cal/g to cal/g, respectively. Generally, briquettes produced from saw dust residue and the paper pulp binder had better quality of fuel and this could be used as an alternative source of energy and proper waste management option. PubDate: Thu, 31 Mar 2022 06:35:01 +000
Abstract: Used tyres are not biodegradable, and the current methods of disposal pose a threat to the environment. Such tyres can be valorised through decomposition to produce liquid fuel, an alternative diesel fuel, using thermal pyrolysis technique. Microwave pyrolysis is an alternate method which uses microwave irradiation, saves energy, and is better environmentally. The main objective of this study was to perform microwave pyrolysis of used tyres to produce liquid fuel and compare with thermal pyrolysis. The specific objectives were to study the effects of pyrolysis operating variables and optimization of liquid fuel yield for thermal pyrolysis, compare with microwave pyrolysis, and characterize the liquid fuel. Thermal pyrolysis variables were reaction temperature, reaction time, and particle size. Thermal pyrolysis reaction temperatures were 200, 300, 400, 500, 600, and 700°C; reaction time 10, 20, 30, 40, 50, 60, 70, 80, 100, and 120 minutes. Particle sizes were 25, 50, 60, 100, 125, and 200mm2. Thermal pyrolysis was carried out in furnace fabricated using furnace clay rated 600 W. A 500 ml round bottomed flask was used as a reactor. Design Expert 13 was used for data analysis and optimization, gas chromatography–mass spectrometry (GC-MS) was used for chemical composition analysis, while physiochemical properties were tested using standard methods. The yield of the liquid product was correlated as a quadratic function of the reaction variables. Response surface methodology (RSM) was used to study the effects of operating variables and identify points of optimal yields. The yield decreased as particle size increased. Yield increased with increase in temperature optima being 500°C. Yield increased with increase in reaction time, and the pyrolysis time was 80 minutes. The highest liquid yield of 40.4 wt. % corresponded to temperature of 500°C, time of 80 min for 60 mm2 size. The calorific value for liquid fuel was 47.31 MJ/kg and GC-MS analysis showed that the oil comprised of complex mixtures of organic compounds with limonene, toluene, and xylene as major components. When compared to the published literature on microwave pyrolysis, both processes gave similar maximum yield but microwave process was superior due to a 77.5% reduction in reaction time, resulting in a 73.02% saving in energy requirement. PubDate: Sat, 12 Mar 2022 08:35:01 +000
Abstract: The study is aimed at evaluating the availability of agriculture residues for syngas production, a case study for Sudan. 10 types of biomass are investigated: sugarcane (bagasse), cotton stalks, sesame straw, groundnut shells, maize straw, sorghum straw, millet straw, sunflower husks, wheat straw, and banana leaves. The available biomass is about 11 Mt/year (3.68 Mtoe). Aspen plus software is applied to simulate the gasification process. The study covered a wide range of operating conditions of steam to biomass ratio () and equivalent ratio (). For all types of syngas characteristics, H2 is 0.32-0.42 (mole fraction), CO is 0.13 to 0.16 (mole fraction), LHV is 5.0 to 8.0 MJ/kg, and the yield is ≥1.5. Wheat, groundnut, and sunflower have the best characteristics, while millet and bagasse yield the poorest characteristics. In addition, all types of syngas have except Millet. These characteristics make all types of syngas except millet suitable for both energy and industry applications. The potential syngas production is 14.17 Mt/year. PubDate: Mon, 21 Feb 2022 12:20:02 +000
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