Papers by Keyword: Economic Analysis

Abstract: In Lima, many concrete structures experience accelerated deterioration due to physical and chemical factors, limiting their durability. This study evaluates the effect of recycled glass powder (RGP) and a nanosilica additive (1.5 %) on concrete with f’c = 27.5 MPa (280 kg/cm²), focusing on optimizing its mechanical properties, durability, and economic feasibility. Mixtures with 10 %, 15 %, and 20 % cement replacement by RGP were prepared, assessing compressive, tensile, and flexural strength, as well as permeability and water absorption. The mixture with 10 % RGP (RGP-10) showed the best early age mechanical performance, increasing compressive strength by 39.1 %, tensile strength by 12.7 %, and flexural strength by 26.2 % compared to the concrete control. Mixtures with 15 % and 20 % RGP showed lower initial strength, although future gains are expected due to delayed pozzolanic reactions. Regarding durability, RGP-10 reduced permeability by 9.02 % and water absorption by 6.45 %, while RGP-15 and RGP-20 achieved even greater reductions, with permeability decreasing by 11.48 % and 9.84 %, and water absorption by 8.68 % and 10.56 %, respectively. Although the nanosilica additive increases the initial cost, its combination with RGP produces significant improvements in mechanical properties and durability, contributing to a reduction in maintenance related costs, resulting in a durable, sustainable, and economically viable material.

Abstract: The mobilized thermal energy storage system (M-TES) has been investigated for decades, demonstrating its competitiveness compared to conventional heating systems like oil, gas, and biomass boilers. This paper presents a case study where waste heat from a power plant is utilized in M-TES to cover heating, cooling, and water heating needs in a university campus. Erythritol is used as the phase change material (PCM) and Therminol55 as the heat transfer fluid (HTF). The study simulates the charge, self-discharge, and discharge phases of the PCM, revealing that increased HTF flow reduces charging time and enhances efficiency, while increased waste heat potential decreases charging efficiency slightly. Economic evaluation shows that heat costs decrease with larger project scales and more PCM containers. This research highlights M-TES as a sustainable thermal energy storage solution with broad applications in the energy sector.

Abstract: Ammonia can be produced from a wide range of raw materials such as coal, natural gas, coke and oil. Coal gasification is a process that converts biomass or fossil fuel-based carbonaceous materials into CO, H₂ and CO₂. A cryogenic air separation process was used to obtain oxygen from air because of high purity and high amount of oxygen, which will be used for coal gasification. For an ammonia synthesis process using pure oxygen gasification, the energy consumption of cryogenic air separation occupies a large proportion. The aim is to reduce energy consumed in the ammonia plant. The models of the process were developed with the aid of Aspen Plus. The energy consumption of the different processes was obtained through energy analysis, economic analysis and sensitivity analysis. From the three simulations, it can be seen that Simulation 3 produced oxygen with the highest purity of 0.979. From the energy analysis, the energy consumed on the total utilities in Simulation 1 was 5.626×10¹⁰ BTU/h with an energy savings of 1.55%, the energy consumed in Simulation 2 was 5.286×10¹⁰ BTU/h with an energy savings of 1.53% while the energy consumed on the total utilities in Simulation 3 was 1.425×10⁹ BTU/h with an energy savings of 74.90%. Simulation 3 consumed the least energy. The economic analysis showed the total cost of each plant for a 10-year duration. Simulation 1 had a total operating cost of 42.083 billion USD/year, Simulation 2 had a total operating cost of 41.9615 billion USD/year and Simulation 3 had a total operating cost of 918.841 million USD/year. Therefore, Simulation 3 consumed the least cost of total operation. It can also be seen that the higher the energy consumption in a plant, the higher the total cost of the plant as Simulation 3 consumed the least energy, which justified that. Simulation 3 is the air separation plant that optimises the energy consumption, thereby reducing the energy consumed in the whole ammonia plant.

Abstract: In Ethiopia, and particularly in the Amhara region, the government as well as the concerned organization would not give special attention to establishing wind energy plants. Lack of scientific research inputs about potential assessment can be one of the reasons behind it. In this paper, a wind energy potential assessment for Debel, Malawa, Enwari, and Ayba Eyesus sites in the Amhara region has been investigated. Five statistical distribution methods namely Weibull 3P, Weibull 2P, Rayleigh 2P, Normal, and Lognormal are used to fit the data to the probability density function and cumulative distribution function. The proposed parameter estimation method, to precisely predict the values of the shape parameter, scale parameter, and location parameter, was the Maximum Likelihood Estimation Method (MLE). To analyze the goodness of fit of the models, Kolmogorov, Andersen Darling, and Chi-Square have been used. The test indicated that Weibull 3P is the best fitting method, except for Ayba Eyesus, which is suited to Weibull 2P. For Debel, Malawa, Enwari, and Ayba Eyesus, the maximum annual average wind power density was found to be 74.291 W/m², 19.183 W/m², 68.972 W/m², and 49.221 W/m² correspondingly. The evaluations show that VENSYS 87 turbine model has better performance in all three sites except Enwari, where Inox Wind DF 100 is favored. With their best performance turbine, the capacity factor of the sites is determined as 14%, 7%, 12%, and 14% for Debel, Malawa, Enwari, and Ayba Eyesus respectively. Furthermore, Economical analysis by initial cost, lifetime, operation, and maintenance cost, has been carried out to estimate the cost of energy. With VENSYS 87 turbine model, the three sites' present value costs are $5,479,586, while it costs $7,306,115 in Enwari with Inox Wind DF 100 turbine. The cost of electricity per kWh is estimated to be $0.00231, $0.00455, $0.00391, and $0.00312 for Debel, Malawa, Enwari, and Ayba Eyesus respectively, and it is significantly lower than the cost from Ethiopian electric utility (EEU), which is around 0.009$/kwh. Access to electricity in Ethiopia was reported at 45% in 2019. This indicates there is a shortage of energy in the country. This kind of study can help authorities and policymakers in taking into account wind power to mitigate energy poverty in the country.

Abstract: Waste from plastic products can be considered complex materials, making recycling a challenge. PET and LDPE are common type of plastic that is easily found in garbage pile. This research was conducted to study the potential of plastic waste conversion into solid fuel to reduce the accumulation of this waste in the environment. The conversion method is to use an extruder. An economic analysis was performed to measure the feasibility of this recycling method. PET and LDPE plastic waste were recycled into pellets using simple heated-extruder equipment after being shredded into small flakes. The extruder temperature was varied at 120^OC, 130^OC, 140^OC, 150^OC, 160^OC, and 180^OC. The optimum temperature for LDPE pellets is 120^OC, and PET pellets is 130^OC. The highest density LDPE pellets is 966.7 kg/m³, and PET pellets is 1320 kg/m³. The highest compressive strength LDPE pellets is 1041.1 kg/m², and PET pellets is 615.2 kg/m². The calorific value of the recycled LDPE and PET pellets is 43.52 mJ/kg and 27.26 mJ/kg, respectively. The moisture value in each plastic pellet did not change significantly by temperature difference. Meanwhile, the economic feasibility analysis shows an NPV of Rp4,394,049,079; IRR of 25.18%; B/CR of 1.465; and PP of 5.95 years.

Abstract: Chemical conversion of carbon dioxide (CO₂) to methanol has the potential to address two relevant sustainability issues: economically feasible replacement of fossil raw materials and avoidance of greenhouse gas emissions. However, chemical stability of CO₂ is a challenging impediment to conversion, requiring harsh reaction conditions at the expense of increased energy input, adding capital, operational and environmental costs. This work evaluates two innovative chemical conversion of CO₂ to methanol: the indirect conversion, which uses synthesis gas produced by bi-reforming as intermediate, and the direct conversion, via hydrogenation. Process simulations are used to obtain mass and energy balances, needed to support economic analyses. Due to the uncertainties in the raw material prices, including CO₂ and hydrogen (H₂), its limits for economic viability are estimated and sensitivity analyzes are carried in predetermined prices (base cases). It is considered the scenario of free CO₂ available in atmospheric conditions, as in a bioethanol industry, but the sensitivity analyses show the results for other scenarios, as in a CO₂ rich natural gas, in which the cost of processing CO₂ is zero. The economic analyses show that hydrogenation can be feasible if hydrogen prices are lower than 1000 US$/t, while the indirect route is viable only for cheap sources of natural gas below 3.7 US$/MMBtu. The CO₂ pre-treatment costs are not as sensible as the others raw materials.

Abstract: Water requirements in Egypt are growing due to population rise, improving living standard, and agriculture expansion. Nowadays, the agricultural sector represents the largest amount of the total water consumption in Egypt. In addition, the Egyptian government goal is to reclaim - as much - land in the desert to meet the food needs. In Egypt, most of electric energy depends on diesel powered generators; furthermore, desert areas are far away from the electric grids. These are the current considerable problems to reclaim desert in Egypt. On the other hand, delivering and using diesel is facing different economic and environmental risks due to its raising price as well as air pollution and global warming. Sustainable development is a challenge of Egyptian government; therefore, using solar energy applications can serve the unique needs of Egyptians who inhabit in desert area. One of these applications is the “off-grid solar water pumps” that discharge underground water from deep wells for agricultural uses. In this paper an economic study is presented to compare between using pumping system powered by traditional fossil fuel and another system powered by solar energy generated from PV panels to operate a farm in the desert fringes. The water pumping system is designed to irrigate a farm of 10 feddans. Based on the results of this study, it is recommended to use solar energy in desert reclamation due to its long run efficiency, environment conservation, and lower total life cycle cost.

Abstract: Hybrid additive manufacturing technologies combine selective material deposition with a conventional milling process in one machine, enabling the production of complex metal parts and reducing the need for part specific tools. The hybrid technology offers technological advantages compared to more established additive fabrication processes, such as powder bed fusion. Compared to powder bed based additive processes, which are currently in a prevailing positon regarding AM adaption, hybrid additive technologies enable increased build rates, enhanced build volumes and a reduction of machine changes. In the Laser Metal Deposition (LMD) process, metal powder is deposited through a nozzle and melted by a laser on the surface of the part. By integrating the LMD process into a machining center, good surface roughness and low tolerances can be realized by means of e. g. milling without reclamping. In comparison to powder bed based processes, cost and resource input have not been investigated in detail. In this study, hybrid additive manufacturing technologies are analyzed regarding cost and resource input. A cost model for hybrid additive processes is introduced that enables the analysis of the manufacturing cost structure for a given part. Furthermore, the resource inputs for the operation of a hybrid production machine are estimated.

Abstract: This article discusses the conditions for and benefits of using the GPS technology and cost-effectiveness analysis of implementing the technology at a transport business. The GPS technology allows transport businesses to streamline their business management processes. This includes not only monitoring, but also supervision, including online supervision, of the process of delivering transport services. In particular, the technology allows transport businesses to identify the location of its vehicles, to monitor the work of their drivers and to modify the service delivery process to reflect new circumstances as they occur.

Abstract: The present paper investigates the generation expansion planning in the context of microgrids. A microgrid consisting of micro hydro turbine, PV array, biomass generator, diesel generator and batteries is integrated to a distribution grid. The microgrid is aimed to dispatch the load demand and transmit the extra power into the grid. The expansion planning is carried out with different sizes of the distributed generation sources. The dispatch strategy is decided by the optimization algorithm with objective function of minimizing the overall costs subject to constraints on minimum reserve margin, maximum fuel threshold and maximum environmental emissions. The optimization is realized using HOMER. The evaluation results show that the planned system is both technically and economically viable even in the presence of constraints.