Advances in Science and Technology Vol. 142

Abstract: This research employs a multiple linear regression analysis to explore the relation-ships between economic and population dynamics and electricity consumption within Ghana. From the multiple linear regression analysis, we deduced coefficients and p-values for the independent variables, highlighting significant predictors. While some variables lack statistical significance, those that are significant yield insights into resource allocation. Notably, economic growth indices demonstrate a meaningful relationship with electricity consumption, while Population provides valuable yet less statistically significant in-sights. In conclusion, this research’s multiple linear regression analysis furnishes actionable insights for energy resource allocation in Ghana. Understanding the complex interplay between economic growth, population changes, and electricity consumption empowers stakeholders to make informed decisions that bolster energy security, sustainability, and economic growth. Though illuminating, this study acknowledges certain limitations and calls for further research to refine our comprehension and inform comprehensive energy strategies.

Abstract: This paper aims discuss the concept of clean mobility, the energy requirements of clean mobility, challenges caused by unclean mobility as well as looking forward to the attainment of clean mobility system. The urban transport situation is as precarious as in the rural transport. Due to population growth and urban sprawl, there is rural-urban drift which has brough about an increase in the number of urban centres across the globe and coupled with the high dependence on fossil fuel, this has led to the continuous growth of air pollution and Green House Gas (GHG) emission level. Such pollution level has serious health effects and sometimes led to several death and contributes to climate change. Vehicular emissions are one of the major pollutant’s sources today with road transport as the key source of the PM2.5 pollution in large cities across the globe. This is due to several reasons including high vehicle density, old emission control technologies, fuels’ high Sulphur content, and limited public transportation options.Clean mobility will help to cut down on health cost and premature death due to air pollution, mitigate climate change actions and economic impacts of mobility. This paper will discuss issues such as stakeholder analysis on existing mobility systems and how to make it clean, policy framework and guidelines and public private partnership in the mobility sector. Therefore, the government in partnership with the private sector and multilateral agencies would have to invest in sustainable modern electric trains, Electric Mobility systems, build ports near deep rivers and create more local and international airports, and ensure people can afford to use them as well as explore the use of alternative fuel with less pollutants and reduced impact on the climate such as natural gas and hydrogen (green, blue, grey) as the case may be.

Abstract: Biodiesel, with the potential to reduce emissions, is an attractive source of renewable energy in the transportation sector, which supports blending of diverse sources such as soybean oil, coconut oil, groundnut oil, palm oil and waste cooking oil. This study presents an analysis of using positive valve overlap of 32 degrees on the performance and emission of a diesel engine fired by biodiesel from two sources (waste cooking oil biodiesel and palm oil biodiesel). The waste cooking oil (WC) and palm oil (PO) biodiesel were blended with diesel fuel in varying proportion of B5, B10, B15, B20, B50, B85, B100. A 2-cylinder diesel engine model was created in Ricardo Wave software environment where simulations were conducted to evaluate brake specific fuel consumption, brake thermal efficiency, brake torque, exhaust gas temperature, CO, HC, and NOx emission. Performance results shows that at 1200 rpm, brake specific fuel consumption of 0.28798 kg/kWh for B100 and 0.27895 kg/kWh for PO100, brake thermal efficiency of 32.55% for B100 and 32.66% for PO100, and brake torque of 33.51N.m for B100 and 34.60 N.m for PO100. Emission results shows that CO emission of 15.10 ppm for B100 and 18.03 ppm for PO100, HC of 45.36ppm for B100 and 45.24 ppm for PO100; NOx of 154.03 ppm for B100 and 167.53 ppm for PO100. The implication is that the palm oil derived biodiesel uses less fuel and produces more brake power and brake torque as compared to waste cooking oil biodiesel. Conversely, emission results show that the palm oil derived biodiesel produces more emissions than waste cooking oil biodiesel.

Abstract: A design of 225[metric tons per year] of an acetone plant from isopropanol alcohol (IPA) was developed. The design considers the fundamental principles of mass and energy balance to size the units of the acetone plant, particularly the Gibbs reactor, separator, absorber, and distillation columns. The beauty of plant design is to account for the material and energy conservation principles interactions and specify the dimensions of the main unit operations of the plant. The HYSYS simulation software was used to design the acetone plant, and the properties of the fluid were used to manually size the plant. The four components resulting from the reaction of IPA and water (acting as a catalyst) to obtain acetone and hydrogen are 2-propanol, acetone, hydrogen, and water. The balance of how these components is heated, reacted, cooled, separated, absorbed, and distilled of acetone from a mixture of IPA/water is shown logically with sketches for the material and energy values of the key unit operations of the plant. The mechanical design of the units was performed to determine the thickness of the columns. In addition, a cost-plus-economic analysis of acetone was carried out. The results indicate that, the sizing of the units gave the following results viz: manually, the reactor with sized 5.4 [m³], 1.56[m] and 2.34[m] as the diameter and height respectively, the separator was sized to 1.78[m] diameter and 2.67[m] height with 6.631[m³] volume, the absorber column gave 0.085[m] diameter, 1.1[m] height, and the distillation column design values are 0.202[m] column diameter, 10.8[m] height and the weir length of 0.154[m]. The overall cost, including the cost of utilities for the entire plant, was [$]7.792million; the equivalent annual operating cost was [$]4.408million; and the thicknesses of the reactor, separator, absorber, and dilation columns are respectively 2.42[mm], 11.71[mm], 1.99[mm] and 3.36[mm]. Validation of the manual design was carried out with HYSYS simulation results, which indicated that the design models were reliable and could be adopted for the design because the deviation values on the specifications of the units are small ranges from 0.04 – 0.4. The result of the design showed that acetone production from the IPA route was recommended and that the HYSYS simulation formed part of the entire design of the acetone plant.

Abstract: The design and energy simulation of carbon dioxide captured process through which Liquefied Natural Gas (LNG) plant has been achieved using Monoethanolamine (MEA) as a solvent. An optimization and technical parameter study for which CO₂ captured process (CCP) from the flue gas of a natural gas liquefaction plant was formed based on absorption/desorption process with MEA solutions, using ASPEN HYSYS. This optimization was aimed at reducing the energy requirement for solvent regeneration, by investigating the effects of CO₂ removal percentage, stripper operating pressure and cooling water flow. Also, the study showed that major energy savings can be realized by optimizing the lean solvent loading the CO₂ transmission phase as well as the stripper operating pressure through the compression and pumping process in the CCP. The specifications, equipment thickness, and cost models were developed based on the principles of conservation of mass and energy, and thermodynamic principles. Aspen HYSYS simulation was carried out on the entire CCP using flue gas of composition carbon dioxide (8.7%), water (17.8%), nitrogen (73.3%), oxygen (0.2%), sulphur dioxide (0.0017%), and nitrox (0.0097%) with input process conditions of pressure 101.6kPa, temperature 150°C and flow rate of 500tons per day. During the study, a minimum thermal energy requirement was found at a lean MEA loading of 0.13, using a 40 wt.% MEA solution and a stripper operating pressure of 130 kPa, resulting in a thermal energy requirement of 1.025 GJ/ton CO₂. Recoveries were done at 75%, 80%, 85%, 90%, 95% and 99% of the simulation process. Suitable correlation models were developed relating to the energy consumption rate per stripper operating pressure and specific thermal energy consumption per solvent flow rate with percentage recoveries. When compared to the simulation result, minimum errors of 0.05% and 2% respectively were obtained. The relationship between the compressor power and CO₂ recovery was linear at a minimum power consumption of 130 kW at 75% recovery while a maximum consumption of 175 kW was obtained at 99% recovery. It was observed that the specific thermal energy consumption per solvent is linearly related to the extent of recoveries, as higher energy was required to recover more CO₂. Compression and pumping with supercritical liquefaction taking the CO₂ above critical pressure of 100bar through three compression sections, inter-cooled to 40°C with water at ambient conditions. Thus, enhancing the high efficiency of the system. The HYSYS simulation results, the process conditions and the characterized flue gas were used for the manual computations to determine the efficiency of the CO₂, the size and specifications of the absorber and the amine regenerator columns. The HYSYS results obtained from the simulation of the entire CCP gave a recovery of 99% of the CO₂ removed from its initial content (8.7%). The energy and thermodynamic analysis of the CCP carried out gave result with the cycle efficiency of 94.92%, an efficient process with 20% energy reduction due to compression and pumping action done by incorporating pumps in the process. The results of the specifications from the material balance of the absorber and amine regenerator columns gave the diameter, height, and number of trays of these units in the CCP as, 2.215m; 10m, and 25, and 2m; 6m, and 20 respectively. While, the thickness results for the ellipsoidal doomed head and cylindrical shell of the absorber and amine regenerator columns were respectively given as, 8.27mm and 8.26mm, and 81.17mm and 78.33mm. The overall cost, including the cost of utilities, for the entire plant was obtained to be $19.629m.