Toxic Gas Emissions Research Articles

Hydrangea inspired hierarchical polyphosphazenes/molybdenum diselenide flame retardant as efficient enhancer for epoxy resin

The extensive use of epoxy resin (EP) is hindered by its high fire risk, particularly due to the significant heat release and emission of toxic substances during combustion. The utilization of organic flame retardant is plagued by its high dosage and subsequent deterioration in mechanical property of polymers. Hence, the integration of polyphosphazenes (PZS) and molybdenum diselenide (MoSe2) was conducted to acquire the hybridized flame retardants of PZS-Mo-A and PZS-Mo-B. With the additions of 3.0 wt% PZS-Mo-A and PZS-Mo-B, the reductions in PHRR reach 31.0 % and 33.0 %, while the decreases in total smoke production (TSP) are 13.4 % and 29.0 %. Moreover, the emission of toxic CO gas is impeded efficiently. This study provides promising prospects for the development of MoSe2-based hierarchical flame retardants, potentially expanding their applications in polymer composite materials.

Innovative Solutions for Sustainable Space Heating: Integrating Solar Air Heaters and Low-Cost Retrofitting Windows for Hilly Region of Kashmir

The Kashmir valley experiences a moderate climate, characterized by cool springs and autumns, mild summers, and cold winters, necessitating heating for approximately 5-6 months annually. Due to unreliable power supply, traditional heating methods such as gas heaters, wood fires, or Kangri's are often relied upon, despite their adverse health and environmental impacts due to emissions of toxic gases. Therefore, there is a need of transition towards non-conventional energy sources. Solar air heaters emerge as a viable option, converting solar radiation into thermal heat which is then delivered to living or working spaces. In addition to minimizing energy requirements for space heating, strategies to reduce heat loss can further enhance energy efficiency. Developing low-cost retrofit window solutions to improve the thermal efficiency of existing windows proves instrumental in this regard. Retrofit windows, designed to fit into existing frames, improve insulation and reduce energy loss without requiring costly renovations. The primary aim of these retrofit windows is to optimize energy efficiency affordably, minimizing heat transfer and preventing air leaks, thereby reducing energy consumption and utility bills while enhancing indoor comfort by maintaining stable temperatures. The several tests were conducted on a thermally insulated test room of size 12*8*10 cubic feet room for solar air heaters under various atmospheric conditions gives a temperature increases of up to 10°C within one hour under different parameters. Furthermore, retrofitting demonstrated a 45.69% reduction in energy requirements at a very affordable cost.

CFD Analysis into the Breakdown of Catamaran Resistance Based on the Original Formula by Insel and Molland

Over the last 40 years, the use of fast catamaran has progressively developed attributed to its unique characteristics on resistance and seakeeping. The advantages have also been applied to military vessels to gain both resistance and seakeeping benefits. The current study focuses on the resistance of catamaran warships to provide less resistance, therefore, the size of engine and emission of toxic gases to the atmosphere. The total resistance of a catamaran will be different from a monohull of equal displacement. There are several factors including viscous interference factors such as φ, which is introduced to take account of the pressure field change around the hull, σ takes account of the velocity augmentation between the two hulls and calculated from an integration of local frictional resistance over the wetted surface, and τ is the wave resistance interference factor change. Those resistance components were developed by Insel and Molland in the 1990s. The investigation discusses the derivation of those components numerically using Computational Fluid Dynamics (CFD) approach. The speeds (hence, the Froude numbers) are varied from 0.2 to 0.6 and the separations between the hulls (S/L) are made between 0.2 and 0.4 so the comparative purposes can be done against the classical work of Insel and Molland and other published data.

Experimental study of the effect of senilia senilis as a partial replacement for cement in concrete production: towards sustainable construction materials

The world today, is plagued by several environmental problems including air pollution and global warming. These aforementioned environmental problems are prominently associated with the consumption of natural resources in manners that have proven to be unsustainable. The construction industry has been seen to play a major role in contributing to the natural resources consumption and environmental problems, at large. Cement production brings about the emission of toxic gases that pollute the atmosphere, thereby promoting these environmental problems. Consequently, concrete technology findings have been directed toward realizing alternative sustainable materials for utilization in the construction industry. Seashell waste has proven promising in the partial replacement of cement in concrete. This study had carried out experimental investigations on senilia senilis shell as a partial cement replacement material in concrete production. The senilia senilis shell was crushed into senilia senilis powder (SSP), processed, and utilized to partially replace cement at 10%, 20%, 30%, 40%, 50%, and 60% in concrete. Fineness, Initial and final setting, and specific gravity tests were carried out on seashell powder to ascertain its suitability for cement replacement. Physical and mechanical tests were carried out on the concrete samples produced. The mechanical properties of the various concrete specimens were also analyzed in this study. Also, the elemental composition and morphological analysis of the SSP and the various concrete specimens were examined in this study with the use of a Scanning Electron Microscope (SEM) and energy-dispersive X-ray (EDX). The results of this study indicate that SSP concrete at 10% to 20% replacement of cement, can be utilized for various mix ratios in the construction industry.

Green and sustainable metal-reinforced bamboo composites with high self-bonding performances

Although the metallization of wood and bamboo has been successfully achieved, challenges such as low efficiency, high costs, and environmental pollution caused by liquid chemical wastes have impeded its widespread adoption in manufacturing. This study presents a novel approach to fabricating metal-reinforced bamboo composite (MRBC) with exceptional performances, utilizing bamboo residues and nano-CuO without use of adhesives. The impact of raw material characteristics, including moisture content of bamboo powder and the amount of nano-CuO additive, on functional properties such as water resistance, flame retardancy and smoke suppression of MRBC was investigated. Also, the forming mechanism of MRBC was elucidated through examination of its microstructure, chemical composition, and thermal stability. Results indicated that the MRBC containing 20 wt% nano-CuO exhibited a high modulus of rupture (MOR) of 54 MPa, an impressive modulus of elasticity (MOE) of 9.3 GPa, a notable surface hardness of 44.4 kgf/mm, and low 24 h water absorption-thickness swelling of 6.5 %, all significantly surpassing those observed in conventional panels. The MRBC exhibited a tightly wrapped, adhered, and cross-linked process under high temperature and pressure conditions, facilitated by multiple synergistic effects such as lignin melting, hydrogen bond networking, physical structure entanglement, and material redox reaction, which contributed to a dense intertwined and consolidated structure. The MRBC demonstrated exceptional structural integrity throughout the combustion process, effectively mitigating potential damage caused by structural collapse due to the incorporation of nano-CuO, which also successfully suppressed smoke and toxic CO gas emissions during combustion. The MRBC showcased advantages of environmental friendliness, water resistance, high strength, flame retardancy and smoke suppression. These attributes position it as an optimal substitute for conventional panels and make it suitable for replacing metals in specific applications. Thus, it demonstrates significant market potential and promising prospects for sustainable development.

Catalytic oxidation of CO over CuO@TiO2 catalyst: The relationship between activity and adsorption performance

AbstractThe emission of CO toxic gases seriously endangers environmental safety and human health. At present, the use of catalysts for catalytic oxidation of CO has become the mainstream research direction. In this study, CuO@TiO2 catalysts with different ratios were prepared by solvent hydrothermal method, and the effects of reaction pretreatment temperature and other factors on the catalytic oxidation performance of CO were investigated. The experimental results show that the catalyst can achieve 100% conversion of CO at 115°C under the condition of pretreament at 350°C for 2 h. This excellent performance is due to the uniform distribution of the active component on the surface of the TiO2 support, and the large pore structure constructed by the solvent hydrothermal method enhances the adsorption and activation of CO. This work provides an idea for the preparation of CO oxidation catalysts.

Efficiency evaluation of commonly used methods to accelerate formaldehyde release and removal in households: A field measurement in bedroom

Modern home interiors are prone to toxic gas emissions, such as formaldehyde, which can lead to respiratory diseases and cancer. Therefore, removing formaldehyde from households is crucial. This study measured the effects of common household factors (air temperature and light intensity) on formaldehyde release, and evaluated the efficiency of various removal methods (pothos, activated carbon, TiO2 suspension, and ventilation) in bedroom. The formaldehyde release rate (K) ratio at different air temperatures: K16 °C:K21 °C:K26 °C = 0.474:1:1.65. Under different light conditions: KUV-125lx:KUV-324lx:KINB-117lx = 2.407:4.099:1. Regarding formaldehyde removal, Pothos initially contributed to a fluctuation in formaldehyde concentration (C) due to vapor release, but had minimal overall impact on removal. Activated carbon and TiO2 suspensions can remove formaldehyde. Activated carbon initially caused C to decline, followed by a subsequent increase. The TiO2 suspension increased humidity, leading to an initial rise in C, followed by a decrease to a stabilized level. Ventilation led to a rapid drop in C, followed by an increase, and finally a decline, due to the dynamic balance between ventilation and K. Comprehensive evaluation of the net formaldehyde removal rate per unit volume (or per unit leaf area for pothos) revealed: activated carbon >TiO2 suspension >pothos. At different air change per hour (ACH), the ratio of time required for formaldehyde removal (t) was tACH-10.89:tACH-54.39:tACH-108.78 = 1.825:1:0.754. Effect size analysis showed that Cohen's d for primary data was >0.5, combined with the K, C, and t results, temperature and UV irradiation were positively correlated with formaldehyde release, while ACH and activated carbon amount were positively correlated with formaldehyde removal.

The Correlation of the Smart City Concept with the Costs of Toxic Exhaust Gas Emissions Based on the Analysis of a Selected Population of Motor Vehicles in Urban Traffic

The intensive development of road transport has resulted in a significant increase in air pollution. This phenomenon is particularly noticeable in urban areas. This creates the need for analyses and forecasts of the scale and extent of future emissions of harmful substances into the environment. The aim of this study was to estimate the costs of the emission of toxic components of exhaust gases generated by all users of conventionally propelled vehicles travelling on a section of urban road in the next 25 years. The traffic study was carried out on an urban traffic route, playing a key role for road transport in the dimension of a given urban agglomeration. The traffic forecast for the analysed road section was based on the results of our own measurements carried out in April 2023 and external data from the General Directorate for Roads and Motorways. The results of the observations concerned six categories of vehicles for the morning and afternoon rush hours. Based on the data obtained, the generic structure of the vehicle population on the analysed section and the average daily traffic were determined. Using the methodology contained in the Blue Book of Road Infrastructure, parameters were calculated in the form of annual indicators of traffic growth on the analysed section, travel speed, and annual air pollution costs for selected vehicle categories, remembering at the same time that the Blue Book-based methodology does not distinguish between unit costs in relation to the type of emissions. The results of the study confirmed that there was an increase in the cost of toxic emissions for each vehicle category over the projected 25-year period. The largest increases were seen for trucks with trailers and passenger cars. In total, for all vehicle categories, emission costs nearly doubled from 2024 to 2046, from EUR 3,745,229 to EUR 7,443,384, due to the doubling of the number of vehicles resulting from the traffic forecast. The analyses presented here provide an answer to the question of what pollution costs may be faced by cities in which road transport will continue to be based on conventional types of propulsion. In addition, the research presented can be used to develop urban mobility transformation plans for the coming years, within the scope of the widely promoted smart city concept and the idea of electromobility, by pointing out to local authorities the direct economic benefits of these changes.

Adsorption and Sensing Properties of Ni-Modified InSe Monolayer Towards Toxic Gases: A DFT Study

The emission of toxic gases from industrial production has intensified issues related to atmospheric pollution and human health. Consequently, the effective real-time monitoring and removal of these harmful gases have emerged as significant challenges. In this work, the density functional theory (DFT) method was utilized to examine the adsorption behaviors and electronic properties of the Ni-decorated InSe (Ni-InSe) monolayer when interacting with twelve gases (CO, NO, NO2, NH3, SO2, H2S, H2O, CO2, CH4, H2, O2, and N2). A comparative assessment of adsorption strength and sensing properties was performed through analyses of the electronic structure, work function, and recovery time. The results show that Ni doping enhances the electrical conductivity of the InSe monolayer and improves the adsorption capabilities for six toxic gases (CO, NO, NO2, NH3, SO2, and H2S). Furthermore, the adsorption of these gases on the Ni-InSe surface is characterized as chemisorption, as indicated by the analysis of the adsorption energy, density of states, and charge density difference. Additionally, the adsorption of CO, NO, NO2, and SO2 results in significant alterations to the bandgap of Ni-InSe, with changes of 18.65%, 11.37%, 10.62%, and −31.77%, respectively, underscoring its exceptional sensitivity. Moreover, the Ni-InSe monolayer exhibits a moderate recovery time of 3.24 s at 298 K for the SO2. Consequently, the Ni-InSe is regarded as a promising gas sensor for detecting SO2 at room temperature. This research establishes a foundation for the development of an Ni-InSe-based gas sensor for detecting and mitigating harmful gas emissions.

Catalyst-free sustainable epoxy vitrimers with fire safety offered by phosphorus-containing compounds

In this study, we designed and incorporated a phosphorus-rich compound, DPT, which possesses inherent catalytic properties, into a typically sustainable epoxy vitrimer. This innovative strategy enables the fabrication of flame retarded epoxy vitrimers that require no additional catalysts. DPT was synthesized through a reaction between triethanolamine (TEA) and dibenzyl chlorophosphonate (DPCP). The successful synthesis of DPT is attested to by FTIR and NMR analyses. DPT effectively accelerated the curing process of the epoxy vitrimers, yielding materials with exceptional mechanical strength and inherent self-healing abilities. Notably, the pHRR of epoxy vitrimer incorporated with DPT is reduced to 296.3 kW/m2, showing a remarkable 54% reduction compared to that of the epoxy vitrimer catalyzed by conventional catalysts. The THR is also decreased from 84.3 to 42.4 MJ/m2. Comprehensive analyses using cone calorimetry and TG-FTIR revealed that DPT effectively inhibits the emission of toxic gases. Crucially, the presence of DPT in the epoxy matrix facilitated the formation of a dense and stable phosphorus-laden carbon layer, which not only enhanced flame retardancy but also imparted exceptional smoke suppression capabilities. These findings underscore the potential of DPT for developing high-performance, catalyst-free, flame-retardant epoxy vitrimers.

Study on high-temperature emission behaviors of crumb rubber modified asphalt: Experimental analysis and molecular simulation approach

The harmful emissions produced during the manufacturing and construction processes of crumb rubber modified asphalt (CRMA) significantly hinder its widespread application. Addressing this issue hinges on a thorough investigation into the mechanism governing its high-temperature emissions. This study employed microscale testing methods to analyze the microstructure and chemical property disparities between CRMA and base asphalt (BA). Subsequently, the impacts of varying crumb rubber (CR) content, experimental temperature, and sulfur stabilizer dosage on the high-temperature emissions of CRMA were investigated. Furthermore, comparative analyses of the molecular weight distribution, emission species, and CR crosslink density in asphalt after the fume experiment were conducted to further elucidate the high-temperature emission mechanisms. Finally, molecular simulation techniques were employed to analyze the interactions between CR and the four fraction molecules of asphalt at the microscale. The results indicated that the fume release volume of CRMA initially decreased and then increased with the addition of CR, while both the experimental temperature and sulfur stabilizer content exhibited a positive correlation with emission volume. CR reduced the volatilization of some small molecular hydrocarbons in the BA by absorbing light fractions. Meanwhile, excessive swelling caused the crosslinking density of CR to decrease by 77 %, which led to the release of toxic substances. At 20% CR content, the overall emissions of CRMA achieve their lowest level; however, the emission of toxic gases does not diminish. Molecular simulations have also confirmed the above results, showing that there is a strong interaction between CR and the light fractions. Compared with asphaltene molecules, rubber molecules had higher molecular polarity and stronger adsorption behavior for light fraction molecules.

Enhanced air filtration and ammonia sensing with cellulose nanofibers-based triboelectric nanogenerators under harsh environments

Fire accidents often occur in environments characterized by severe air pollution, toxic gas emissions, and microbial growth, creating significant challenges for developing multifunctional portable healthcare devices. These devices must achieve high filtration efficiency, minimal pressure drop, and the capability to provide early warnings of toxic gas leaks. Triboelectric nanogenerators present a sustainable solution as self-powered energy converters for advanced healthcare applications. In this study, we grafted Ti3C2Tx/MoS2 nanohybrid materials, which form Schottky heterojunctions, onto cellulose diacetate using tetraethyl orthosilicate, followed by electrospinning to produce nanofibrous films. When paired with a negatively charged material, the resulting device achieved an optimal balance with a low-pressure drop (52 Pa) and high filtration efficiency (98.72 % for PM0.3). It also demonstrated exceptional stability under high-temperature and high-humidity conditions. Notably, the device maintained rapid sterilization within 15 min and consistent filtration performance even after multiple washes. Furthermore, the device exhibited precise detection of trace amounts of NH3 (0.1 ppm) and demonstrated a rapid response, achieving an 86 % response rate within 2 s for 100 ppm NH3, providing an early warning 28 s faster than commercial NH₃ monitors. This study introduces a novel approach to the development of multifunctional, self-powered, wearable medical devices that offer high-efficiency air filtration and sterilization, breath monitoring, and rapid toxic gas leakage detection in harsh environments.

Optimal power management of a stand-alone hybrid energy management system: Hydro-photovoltaic-fuel cell

The field of electrical engineering with renewable energy systems has witnessed a remarkable improvement due to an increase in the world's growing population as available resources become limited. This study proposes an optimal and efficient hybrid energy management system that combines photovoltaic, hydro, and fuel cell renewable energy resources that can solve the drawbacks of current energy setups and offer a dependable power source for stand-alone purposes. This novel AC-linked hybrid energy system features a comprehensive power management strategy with actual weather data and a realistic load demand profile. The HOMER Pro technique is employed for calculating the emission of toxic gases, system economic benefits, sensitivity analysis and cost minimization of the system while providing sustainability. The numerical outcomes show optimal results as compared to the existing systems in the literature. The system consists of 55 kW of PV modules, a 30 kW FC generator, and 40 kW of hydropower, suggesting optimal and excellent economic and environmental sustainability. This system appeared to be an especially cost-effective solution, with a net present cost (NPC) of $248,773 and a cost of energy (COE) of $0.0546/kWh. The results show that the system can meet energy needs while utilising the available resources efficiently in different weather conditions. The proposed system has the potential to increase the sustainability and dependability of power generation in a variety of applications and aid in the design and implementation of alternative energy systems, particularly in off-grid or remote areas. The proposed system can be extended to other such locations that will provide a scalable and flexible solution for electricity generation, making it suitable for a variety of applications, from small rural power plants to large industrial power supplies. Overall, the proposed study provides an important resource for development in hybrid energy system design and operation, with far-reaching implications for the transition to a sustainable and low-carbon future.

Enhancing flame retardancy and mechanical strength of glass fiber-reinforced biomass polyamide composites with surface-functionalized black phosphorus

Fiber-reinforced polyamide exhibits exceptional mechanical properties and durability; however, its widespread application is impeded by potential fire hazards. In this study, a hybrid material consisting of black phosphorus (BP) and polyhedral oligomeric silsesquioxane (POSS) was synthesized, denoted as BP-CO-POSS. The fire safety of fiber-reinforced polyamide demonstrated significant enhancement upon the incorporation of aluminum diethyl phosphinate (Alpi) and BP-CO-POSS. This enhancement was evident in various aspects, including the suppression of heat release behaviors, reduction in the emission of toxic gases, and an increase in the UL-94 rating. Notably, with the additional inclusion of 0.5 wt% BP-CO-POSS, a substantial decrease in both heat release rate (31.15 %) and total heat release (37.59 %) was observed when compared to the application of Alpi and BP alone, thus affirming the existence of a synergistic effect. This observation was substantiated through a comprehensive analysis of results obtained from both gas and condensed phases. This study offers a practical methodology for the widespread utilization of phosphorus-rich advanced materials, thereby further enhancing the fire safety of fiber-reinforced polymers.

Gas evolution in self-extinguishing and insulative nanopolysaccharide-based hybrid foams

Lightweight, energy-efficient materials in building construction typically include polymeric and composite foams. However, these materials pose significant fire hazards due to their high combustibility and toxic gas emissions, including carbon monoxide and hydrogen cyanide. This study delves into the latter aspects by comparing hybrid systems based on nanofiber-reinforced silica-based Pickering foams with a synthetic reference (polyurethane foams). The extent and dynamics of fire retardancy and toxic gas evolution were assessed, and the results revealed the benefits of combining the thermal insulation of silica with the structural strength of biobased nanofibers, the latter of which included anionic and phosphorylated cellulose as well as chitin nanofibers. We demonstrate that the nanofiber-reinforced silica-based Pickering foams are thermal insulative and provide both fire safety and energy efficiency. The results set the basis for the practical design of hybrid foams to advance environmental sustainability goals by reducing energy consumption in built environments.

Exploring the potential of boron-nitride nanobelts in environmental applications: Greenhouse gases capture

This study examines boron-nitride nanobelts, including Möbius-type, for capturing and detecting nine greenhouse gases (ammonia, carbon dioxide, carbon monoxide, hydrogen sulfide, methane, methanol, nitric dioxide, nitric oxide, and phosgene). Negative adsorption energies indicate favorable adsorption on both nanobelt types. The systems show recovery times ranging between 2 h to few nanoseconds. Only nitric oxide forms covalent bonds; other gases interact non-covalently. Molecular dynamics simulations reveal consistent single-molecule interactions and attractive forces with multiple molecules. Semi-empirical tight-binding methods, as implemented in the xTB software were used for computational efficiency. Results demonstrate the potential of boron-nitride nanobelts for environmental monitoring and remediation of industrial toxic gas emissions, addressing concerns about human health and environmental impact.

Semi-autonomous sensor fusion-based strategy for unmanned aerial atmospheric surveillance system in open field environments

<p>This paper explores the convergence of semi-autonomous systems and sensor fusion for monitoring hazardous atmospheric substances in open and semi-confined environments such as open-pit mines. As the heart of this system, a universal and flexible device leveraging wireless technologies to collect and analyze large volumes of data, designed by the authors, is proposed. The article outlines the key components of the platform, emphasizing its potential for increasing personnel safety levels as stipulated by the international public exposure guidelines. In modern mines, it becomes crucial to monitor elevated concentrations of nitrogen and carbon oxides, as well as other pollutants after blasting and the toxic gas emissions produced by the heavy transportation equipment such as mining trucks and excavators. In this paper, industrial-grade electrochemical sensors are compared with price-affordable but less precise microelectrochemical ones. The performed experiments for lowering computational requirements show promising results. The integration of an ultrasonic anemometer enhances the system’s capabilities, contributing to a comprehensive understanding of atmospheric conditions. In parallel, the research discusses the role of computer vision in autonomous control systems, with a focus on the architecture and processing pipeline of the state-of-the-art system-on-module Kria by AMD. Advocating the potential of adaptive computing for enhanced efficiency in dynamic environments, the paper underlines the importance of the integrated approach in developing a semi-autonomous atmospheric surveillance system and highlights the impact of adaptive computing in dynamic scenarios. The main part of the measuring equipment and methods has been experimented with in real conditions in open-pit mines in Bulgaria. This is an initial phase of ongoing research aimed at serving as a foundation for future improvements and the elaboration of a fully autonomous prototype for hazardous substances evaluation in the atmosphere of open-pit mines.<strong></strong></p>

Flammability, Toxicity, and Microbiological Properties of Polyurethane Flexible Foams.

The aim of the research was to investigate the influence of calcium phosphinate (HPCA) and aluminum phosphinate (HPAL) in synergistic systems with organophosphorus compounds, i.e., diphenylcresyl phosphate (CDP) and trichloropropyl phosphate (TCPP), on the thermal stability, flammability, smoke density, and emission of toxic gases during the thermal decomposition of polyurethane (PUR) foams. Thermogravimetric analysis (TGA), along with cone calorimetry and microcalorimetry, were used to assess the influence of fillers on the thermal stability and flammability of PUR foams. The analysis of toxic gas products was performed with the use of a coupled TG-gas analyzer system. The optical density of gases was measured with the use of a smoke density chamber (SDC). The obtained results showed an increase in thermal stability and a decrease in the flammability of the PUR composites. However, the results regarding smoke and gas emissions, as well as toxic combustion by-products, present ambiguity. On one hand, the applied flame retardant systems in the form of PUR-HPCA-CDP and PUR-HPCA-TCPP led to a reduction in the concentration of CO and HCN in the gas by-products. On the other hand, they clearly increased the concentration of CO2, NOx, and smoke emissions. Microbiological studies indicated that the obtained foam material is completely safe for use and does not exhibit biocidal properties.

The conjoint effect of lab-grown nano-graphene dispersant and omega-9 fatty acid surfactant on performance of CI engine

This article aims to assess the performance characteristics of lab-grown graphene nanoparticles via electrolytic exfoliation as nano additives in engine oil. Physical characterization confirmed the morphology and purity of the prepared graphene nanoparticles. Nanolubricants were prepared at 0.1%, 0.2%, and 0.3% volume fraction of the nanoparticles with the addition of oleic acid as surfactant. Measurements of density and viscosity for the nanolubricants were recorded at varying concentrations and temperatures. The performance parameters of a 4-stroke single-cylinder compression ignition (CI) engine were computed using the formulated nanolubricants. The emission of toxic gases into the environment post-engine performance evaluation was also analyzed for different formulations of nanolubricant samples. Results showed that the relative viscosity variation with concentration for the experimental data was in well agreement with other available predictive models. The nanolubricant with 0.1% concentration yielded a reduction of 13.96 ± 0.39% in total fuel consumption (TFC), a reduction of 5.55 ± 0.17% in brake-specific fuel consumption (BSFC) and an augmentation of 3.96 ± 0.13% in brake thermal efficiency (BTE) in comparison to plain engine oil and other prepared formulations. Also, a marginal reduction in emission of exhaust toxic gases i.e., (2.13 ± 0.1%) ppm in NOx and a significant maximum reduction of 7.46 ± 0.2% in smoke opacity has been obtained with 0.1% nanolubricant sample as compared to other test samples. The results from the present study may be useful for developing sustainable nanolubricants for environmental viability and energy savings.

Using NaOH@Graphene oxide-Fe3O4 as a magnetic heterogeneous catalyst for ultrasonic transesterification; experimental and modelling

Burning fossil fuels causes toxic gas emissions to increase, therefore, scientists are trying to find alternative green fuels. One of the important alternative fuels is biodiesel. However, using eco-friendly primary materials is a main factor. Sustainable catalysts should have high performance, good activity, easy separation from reaction cells, and regenerability. In this study, to solve the mentioned problem NaOH@Graphene oxide-Fe3O4 as a magnetic catalyst was used for the first time to generate biodiesel from waste cooking oil. The crystal structure, functional groups, surface area and morphology of catalyst were studied by XRD, FTIR, BET, and FESEM techniques. The response surface methodology based central composite design (RSM-CCD) was used for biodiesel production via ultrasonic technique. The maximum biodiesel yield was 95.88% in the following operation: 10.52:1 molar ratio of methanol to oil, a catalyst weight of 3.76 wt%, a voltage of 49.58 kHz, and a time of 33.29 min. The physiochemical characterization of biodiesel was based to ASTM standard. The magnetic catalyst was high standstill to free fatty acid due to the five cycle’s regeneration. The kinetic study results possess good agreement with first-order kinetics as well as the activation energy and Arrhenius constant are 49.2 kJ/min and 16.47 * 1010 min−1, respectively.