Papers by Keyword: Catalyst

Abstract: The increasing demand for sustainable energy solutions has intensified research into biodiesel production, which relies on chemical catalysts that have an environmental impact. This study investigates the alternative methods of biodiesel production by utilizing agricultural waste, specifically rice husk, coconut husk, and chicken manure as a catalyst for biodiesel production. Laboratory experiments were conducted to extract metal oxide from agricultural waste to be used as a catalyst in the transesterification process. The obtained ash was characterized, and it was revealed that rice husk ash contained 98% SiO₂, coconut husk ash had 72.62% of K₂O, and chicken manure ash had 46.56% CaO, with higher metal oxide compositions in each material. The transesterification reaction was conducted by varying alcohol to oil ratio from 3:1, 6:1, 9:1, and 12:1, temperature (40-80°C), catalyst concentration (1.5-4.5%wt), and reaction time (20-120min) to assess catalyst efficiency. Pure CaO was used as a control catalyst for comparison. Characterization of the produced biodiesel from all catalysts was conducted and compared to ASTM D6751 standards. The results for acid value, moisture content, density, viscosity, free fatty acid, flash point, pour point, and cloud point were analyzed and found to comply with ASTM D6751 standards. On quantity determination of produced biodiesel, the most effective catalyst was chicken manure ash with a yield of 80% and the least effective catalyst was rice husk ash with 68% yield. Using agricultural waste reduces up to 40% production cost.

Abstract: Since offset printing machines are crucial to the printing process, numerous industry participants take different steps to ensure that offset machine prints are high caliber. Keeping the offset machine's blankets and rollers free of metal contaminants from printing inks is one of the efforts made. Industry participants typically utilize chemical fluids that can clean offset machine blankets and rollers to maintain their cleanliness. However, because these chemicals oxidation with time, using chemical fluids continuously can harm the blankets and rollers. To Impacts the printing outcomes, causing the paper to deteriorate more easily, the blanket to get sticky, the print to be uneven, and the density to drop. Furthermore, the cleaning agents that are employed may pollute water and harm the ecosystem. In this study, an eco-cleaner that can be used in place of current chemicals is created by a fermentation process of organic waste strengthened with a catalyst. To enhance the printing quality of offset machines, this research aims to create an environmentally friendly solution that can lessen metal contaminants on rollers and blankets.An experiment utilizing the fermentation synthesis approach was employed in this study. Additionally, the eco-cleaner is evaluated for feasibility and characterisation in accordance with SNI requirements. The physical characteristics and organic plating tests are conducted, and the test results are analysed to determine whether the eco-cleaner is feasible. Because the eco-cleaner is non-corrosive, the final product efficiently removes metal contaminants without causing harm to the blankets and rollers. Both the printing industry and the general public can use the final products.

Abstract: This study explores the utility of reduced graphene oxide (rGO) as a support material for gold nanoparticles (AuNPs) synthesized via an economically efficient and environmentally friendly electrochemical deposition method conducted at room temperature. Employing a chronoamperometry (CA) method, we successfully synthesize AuNPs in aqueous solutions without additional stabilizing agents. We investigate the influence of substrate and electrodeposition duration on the growth of AuNPs, on indium tin oxide glass substrates and rGO, with electrodeposition durations for comparison. This research highlights the straightforward and rapid one-step synthesis of AuNPs in an aqueous medium and explores the correlation between Au particle size and electrocatalytic performance. We evaluate the electrochemical performance of rGO-supported AuNPs in the context of methanol oxidation reaction (MOR) using cyclic voltammetry in an aqueous medium with an alkaline electrolyte. Notably, AuNPs supported by rGO, featuring an average particle size of 46 nm, exhibit superior electrochemical performance compared to their counterparts with an average particle size of 165 nm when employed as catalysts for the MOR. This superior performance is characterized by a 15 mV more negative oxidation potential (54 mv compared to 39 mV) and over 2.5 times higher oxidation peak current (0.064 mA compared to 0.025 mA), underscoring their efficiency as electrocatalysts for MOR.

Abstract: The research deals with the determination of the temperature distribution in a two-stage porous catalytic medium when the heat flow passes through. The peculiarity of the proposed model of heat and mass transfer in a porous catalyst is to consider the change in the volume of the spherical particle that makes up the catalyst.A program for calculating the temperature distribution in a two-scale porous structure of a catalyst made of spherical particles that change in volume with time has been developed. It should be noted that the temperature gradient is rather high, and the temperature in the central region of the particle becomes high enough for the process of catalytic reaction initiation only after 3.25 s. The developed program together with analytical and empirical studies allow to find the range of temperature and time of heat treatment at which the given thermophysical characteristics of porous material will be observed.The work will be useful for engineers and scientists studying the problems of thermochemical reactors and heat transfer in catalytic fills.

Abstract: This paper delves into the understanding of how dielectric barrier discharge (DBD) non-thermal plasma (NTP) system affects the flue gas compositions and the synergistic effects of DBD-NTP and SCR systems using NTP-downstream-SCR configuration on nitric oxide reduction through the experimental investigation. Simple gas feeds were used to observe the interaction between gases when high voltage discharge was applied. Overall, DBD-NTP was effective in oxidising NO and NH₃ into NO₂ while also reducing NO in the presence of NH₃. When DBD-NTP was installed downstream the SCR catalyst, it demonstrated substantial additional deNOx and reduction of NH₃ slippage. This proposed SCR+DBD-NTP configuration showed a potential to help mitigate low deNOx performance at low temperatures.

Abstract: This study synthesized CaAl₂O₄:Eu²⁺ blue phosphors using the sol-gel method. The effects of incorporating citric acid, poly (oxyethylene) (PEG), and HCl in the precursor on the luminescent properties of phosphors were investigated. No significant changes were observed in the photoluminescence (PL) spectra of the phosphors when different precursor solutions were used. However, the use of PEG and citric acid led to a noticeable decrease in the PL intensity. Notably, the use of HCl resulted in an increase in PL. In addition, upon heating the phosphors from room temperature to 110 °C, the PL spectrum remained unchanged, whereas the PL intensity decreased linearly with increasing temperature. This indicated the suitability of CaAl₂O₄:Eu²⁺ for optical temperature-sensing applications.

Abstract: The article shows the process of preparing an oxide layer on the surface of titanium for use in industrial catalysis. Data from physical and chemical studies are presented, namely microhardness, porosity, thickness, specific surface area, adhesion and thermal stability of the active layer.To determine the physicochemical characteristics of the resulting oxide layer, the following analysis methods were used: X-ray diffraction analysis (XRD), X-ray diffraction phase analysis (XPA), X-ray absorption analysis (XRA), and X-ray fluorescence analysis. The thickness of the oxide layer depending on the duration of anodization was estimated by optical microscopy.

Abstract: Silica based catalyst was prepared from geothermal sludge – solid waste from geothermal exploration - of Dieng Power Station, Central Java, Indonesia. The catalyst was prepared by extracting silica compound from the sludge matrix, followed by sulfonation to obtain sulfonated – solid catalyst. Catalyst sample analysis informed the catalyst was generally amorphous in structures, possessed surface area between 76 – 81 m²/g, with acidity approximately 5-6 mmol/g. Evaluation on catalyst activity was performed by applying it on sago starch hydrolysis - atmospheric pressure and 100 – 150°C (373 – 423 K) - in which more than 90 % conversion could be achieved.

Abstract: Although fossil fuel continues to play a dominant role in global energy system unfortunately their life span is threatened as the fossil reserves are running out. Except for the fact that they are readily available, tried and tested, unfortunately they bring about a negative environmental and climate impact. When the fossil fuels are burned, they produce both carbon dioxide and carbon monoxide which is the largest driver of global climate change and air pollution. This has caused a need to explore and transition to a cleaner and renewable energy resource like biofuel. Biofuel is a combination of fatty acid alkyl esters achieved by the esterification and transterification of triglycerides that can either be animal fats and vegetable oil with methanol and ethanol. Biodiesel provides several positive benefits by helping in decreasing the country’s dependence on the importation of crude oils, it also reduces the greenhouse gas emissions and advances the lubricating property. Biodiesel is produced and deployed globally with China being the country with the highest biofuel capacity in the world, with nearly 29.8 gigawatts as of 2021. It is followed by Brazil which is ranked second, with a biofuel capacity of 16.3 gigawatts. The selection of a feedstock in biofuel production has a noticeable impact as it determines if a biofuel will be formed or not from the transesterification process performed. The fatty acid / triglyceride content especially the Mono-Unsaturated Fatty Acids (MUFA’s) are of interest. The higher the MUFA’s, the higher possibility of a successful transterification hence biofuel being the by-products/formation with less catalyst and alcohol used. Feedstocks with over 40% fatty acids, especially the MUFA’s are favorable for biodiesel formation. Almost 80% of Macadamia’s fatty acids (MFAs) are palmitoleic acids (C16:1; ~20%) and Monounsaturated, mostly oleic (C18:1; ~60%). This study reviews the preparation of biofuel utilizing Macadamia nut oil (MNO) as a feedstock for sustainable biodiesel Production.

Abstract: The work presented here explores how air pollutants form and the prominent thermodynamic opportunities to reduce pollutants formation and emission during internal combustion process. The paper reviews the internal combustion engine operating cycles and discusses the relationship between the formation of pollutants and the engine’s energy management. Octane was used to model gasoline along with a petrol generator used to represent 4-stroke petrol engines. A set of thermodynamic equations were used to approximate the rate of heat transfer and the composition of exhaust gases at varying nitrogen-to-oxygen feed composition. Lowering the N₂ content in the feed air significantly decreases the overall exhaust content of NOx and CO and improves the engine’s power output. The model emphasizes the ability of retrofitting traditional internal combustion engines with a molecular air filter as a promising strategy for reducing the exhausts’ emissions whilst improving the energy performance of the internal combustion process.