Papers by Keyword: Emission

Abstract: Herein, the lithium yttrium fluoride (LiYF4) compound doped with rare-earth Nd3+ ions are synthesized by solid-state reaction methods. The results of XRD, optical absorption, and emission measurements confirm that the doped powder sample was successfully synthesized. The optical properties of Nd-doped LiYF₄ powder samples were investigated through a comparison of ab initio and experimental methods. We predicted the crystal and electronic structures using ab initio total energy calculations within the framework of density functional theory (DFT). Our results for the optical properties, including the dielectric function, absorption coefficient, and refractive index of the Nd-doped LiYF₄ compound, were calculated and compared using the independent particle approximation (IPA), time-dependent density functional perturbation theory (TDDFpT), and random phase approximation (RPA).

Abstract: To perform a comparative study of the performance combustion and emission characteristics of pure diesel and mustered blends, a single-cylinder stationary Kirloskar TV1 Engine.xls engine was used. The ratio of mustered oil blends to diesel was 60%. The mustered blend was selected appropriately and the compression ratio was optimized for this study. From this report it is proven that the most favorable of mustered and diesel blends is 60% of mustered and 40% of diesel with compression ratio 14:1,15:1,16:1 & 17.5:1.In comparison, the release of CO was reduced; however, there was a moderate increase in the release of NOx. Therefore, with only a slight alteration in the present diesel engines, the algae blend can be used.

Abstract: In this article, a picosecond laser source was employed to irradiate the nanostructured ZnO thin film prepared by the sol-gel method. The impact of laser irradiation on the characteristics of a nanostructured ZnO thin film was investigated. Analysis using X-ray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy confirmed a significant influence on the structure of the ZnO thin film. As the duration of laser irradiation (the number of laser pulses) increased, there was a remarkable decrease in both the electronic and photoluminescence intensities of the nanostructured film. Tauc's plot indicates a noticeable change in the optical band gaps of the thin film with the increase in irradiation time. The morphological image suggests that the laser irradiation energy induces both degradation and modification of the film surface, consequently causing changes in the structural, absorption, and photoluminescence properties of nanostructured ZnO. The observed effects are attributed to alterations in the crystal structure and size of the nanostructured ZnO film, as confirmed by XRD. The reduction in photoluminescence intensity observed over the laser irradiation times may be a result of potential degradation in the crystalline structure of the nanostructured ZnO film.

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: This study aims to determine the effect of installing modified copper C-SiO₂-ZSM5 in the exhaust, installing modified copper in the exhaust to reduce CO and HC. The two methods used to reduce CO and HC exhaust emissions are as follows: the first method is by mixing fossil fuels with ethanol. The fuel used is a mixture of gasoline + ethanol with variations of gasoline, E10, and E20. The second method is to provide a CO and HC reformer catalyst made of modified copper with the addition of SiO₂ and MZM5 as much as 10% and 20%, respectively. The test uses a four-stroke two-wheel motor in a neutral gear position. Exhaust emission data retrieval is at 1500, 3000, 5000, 7000, 9000 rpm. With gasoline fuel mixed with ethanol with E 10 and E 20. There is a decrease in CO at each engine speed in each fuel variation, because the more ethanol content, the greater the supply of O₂ in combustion because ethanol has oxygen bonds that can increase combustion. The emission of CO and HC gas on gasoline-fueled motors are greater than those of E 10 and E 20 motors. The use of a copper converter catalyst SiO₂-C-ZSM5 is very significant and can reduce CO levels for gasoline fuel from the highest value of 4,7% to 2.82%, gasohol fuel E 10 with the highest value of CO 3.02% decreased to 1.2% and gasohol fuel E 20 the highest value of CO 2.78% decreased to 0.17%. Changes were seen visually on the surface of the copper used for the CO and HC reduction test, the surface copper became darker in color, especially when testing using gasoline. When using a mixture of ethanol and gasoline, copper is purplish brown color.

Abstract: The global warming phenomenon has led to world climate change caused by high concentrations of greenhouse gases (GHG) especially carbon dioxide (CO₂) in the atmosphere. Carbon dioxide is produced in large quantities from fuel combustions, gas sweetening processes, etc. Since its emission rises annually, some efforts to reduce the emission are, therefore, required. Monoethanolamine (MEA), a primary amine, has been widely used for many years for acid gas removal. To get a better column performance, an accurate physical properties measurement, such as density, needs to be conducted. This study aims to measure the densities of 10 wt.% MEA aqueous solutions at temperatures from 10 to 90 °C and CO₂ loadings up to 0.417 mol CO₂/mol MEA. The results show that the higher the concentration of CO₂ the higher the density at a constant temperature, while the densities decrease as temperatures increase due to volumetric expansion. Besides, an expression to correlate the densities of 10 wt.% MEA aqueous solutions was also developed based on the pure-component molar volumes together with the excess molar volumes. The average error of the measurement was found to be 0.18%.

Abstract: The numbers of Malaysian construction industry had been increasing in several years with the large construction building and infrastructures projects had been constructed. Therefore, these developments led to an increase of cement production. The production of cement will cause wider environmental implication such are air pollution, water pollution and soil pollution which are very dangerous for human health. This is due to the manufacturing of cement that release dust, toxic and carbon dioxide emissions, which is a significant contributor of greenhouse gases. To overcome this problem, several researches had been conducted for the past few decade to find a new waste material that have same mechanical properties which can replace cement content in construction. One of the most promising materials that shows great potential is eggshell as a cement replacement. It is reported that the global egg production will increase to about 90 million tons by 2030, therefore the waste of eggshell will be increased too. This paper study the mechanical properties of eggshell as a cement replacement in concrete. Several papers had been reviewed and the results are presented in order to shows the performance of eggshell in concrete. The result shows that the concrete with less than 15% replacement of eggshell produced higher compressive and tensile strength compared to normal concrete. Moreover, the flexural strength of concrete containing eggshell up to 20% replacement shows comparable results with normal concrete. From the results, by replacing cement with eggshell up to 15% show a good performance as well as can reduce the use of cement and reduce the eggshell wasted in landfill.

Abstract: To tackle one of the major environmental issues concerning modern day mankind, that is air pollution and to reduce dependency on other countries for conventional fuel, finding an alternative fuel is of high priority. Biodiesel is one such alternative. Adding nanoparticles like Carbon nanotubes (CNT) leads to reduction in emissions and enhancement in performance. In this context, in the present paper an experimental investigation was carried out on a computerized single cylinder water cooled diesel engine coupled with an eddy current dynamometer to determine the impact of blending CNT with biodiesel (Neem Oil Methyl Ester or NOME) and a comparative study of various blends using diesel as the baseline was done. The concentration of CNT used were 25 ppm, 50 ppm and 100 ppm CNT blended with B20 biodiesel. The blends were prepared using homogeniser. Readings were recorded for different loads for all the blends and comparative graphs were drawn for performance, combustion and emission characteristics. There was an improvement in the performance characteristics with 8.1% increase in BTE, lowered emissions with 0.0785% decrease in CO and 8.15% decrease in UBHC emissions along with improved combustion relative to diesel when CNT (50 ppm) was added to B20 biodiesel.

Abstract: The aim of this work is to examine the performance, combustion as well as emission characteristics of diesel engine performed for various mixtures of methane-enriched biogas (95% CH₄). Experiments were performed on a single cylinder, four-stroke constant speed, direct injection, water-cooled diesel engine. The engine is operated by means of dual fuel mode using diesel and different mixtures of methane-enriched biogas (BG) like BG10, BG20, BG30, and BG40 mixed with the air (i.e. BG40-40% of CH₄ by volume respectively) for different loads and at injection timing of 27.5° before top dead centre (bTDC). The performance, combustion and emission characteristics of the engine operated by dual fuel mode were experimentally analyzed, and compared with respect to diesel mode. The experimental result reveals that better performance and lower emissions were observed for BG40 compared to other mixtures. The brake thermal efficiency of BG40 is lower by 2.43% compared to diesel at full load. The cylinder peak pressure for dual fuel mode is higher by 6.55% when compared with diesel mode. NOx emission reduced by 2.6 % and CO emission increased by 3.3% compared to diesel at full load respectively. Keywords: Biogas, Energy, Combustion, Emission, Injection timing, dual fuel mode

Abstract: New stringent emission limits require the drastic reduction (80 to 95%) of harmful emissions of NOx and PM. Due to the special characteristics of vessels (long engine lifetime, small series, greater variety of technical configurations) also retrofit after-treatment solutions, or solutions where new engines and after-treatment systems are purchased separately are necessary. For these options economical and effective certification procedures are needed.