Combustion Procedure Research Articles

An Overview of Characterisation, Utilisation, and Leachate Analysis of Clinical Waste Incineration Ash.

As industrial globalisation and waste output continue to grow, solid waste management is one of the most pressing worldwide environmental challenges. Solid wastes include both the heterogeneous mass of urban throwaways and the homogeneous accumulations of agricultural, industrial, and mineral wastes. Clinical waste (CW) has a significant negative influence on both human health and the environment. To dispose hazardous CW, a proper waste management system should be necessary, and incineration should be the best possible option for reducing the volume of this hazardous waste. Incineration is being developed in Malaysia as a means of disposing clinical and hazardous waste. Currently, 170 common CW treatment facilities with 140 incinerators are accessible around the country. The combustion procedure kills pathogens and reduces waste volume and weight, but it leaves a solid residue known as clinical waste ash (CWA), which raises heavy metal, inorganic salt, and organic compound levels in the environment. Because metals are not eliminated during incineration, dumping CWA in a landfill could contaminate groundwater. Leachate is the liquid created when waste decomposes in a landfill and water filters through it. The most common method of disposing of CW ashes is to transfer them to a landfill. Landfills should install a top cover after closure for hazardous waste landfills. Due to a lack of space and the high expense of land disposal, recycling technologies and the reuse of ash in various systems have developed. Clinical waste incineration fly ash (CWIFA), a solid waste substance from CW incineration, typically includes mobile heavy metals and can cause significant pollution when reused. The standard requirement for removing CWIFA in dumpsites should be below the metal limit stated by the U.S. Environmental Protection Agency (USEPA). Much recent research on the usage of CWIFA has concentrated on mitigating their effects on the environment. Several studies have confirmed the utilisation of CWIFA in the construction field and agriculture to reduce the leaching of its hazardous components into the environment. Compressive strength decreased with the percentage amount of CWIFA due to the substitution of cement with CWIFA. CWIFA mix with 20% cement is the broad-scale application of CWIFA for geotechnical constructions. Heavy metals (Cd, Cu, Ni, Pb, and Zn) are strongly immobilised by the cementitious matrix. Solidification/stabilisation (S/S) materials can be dumped in landfills with less environmental protection than untreated waste. When utilising a CWIFA in mortar, the primary environmental concern is if any harmful materials leach out during the initial curing process or throughout the life of the mortar. Toxicity characteristic of leaching procedure (TCLP) analysis of all CWIFA specimens found amounts of heavy metals below regulatory limits. Solidification of waste with cement and solidified waste has become a popular way of minimising the atmosphere's emissions. The amount of CWIFA generated is expected to increase nationally and globally. There is an immediate need for further evaluation of ash leachate investigations for proper disposal and usage of ash in construction materials.

Prediction of coal spontaneous combustion temperature based on improved grey wolf optimizer algorithm and support vector regression

The effective prediction of coal spontaneous combustion temperature is of great importance to the monitoring and prevention of coal mine fires. Aiming at the problem of insufficient prediction accuracy of traditional coal spontaneous combustion temperature prediction model, and considering the characteristics of prediction data samples and the timeliness of applicable models, an improved grey wolf optimized support vector regression coal spontaneous combustion temperature prediction model based on nonlinear parameter control, dynamic inertia weights and grey wolf social hierarchy is proposed, and the effectiveness of the improved grey wolf optimizer algorithm is verified by numerical experiments. The O2 concentration, CO concentration, C2H4 concentration, CO/ΔO2, and C2H4/C2H6 selected from the coal spontaneous combustion procedure warming experiment were used as the input indexes of the prediction model, and the coal body temperature was used as the output index, and the prediction model was compared and analyzed with the particle swarm optimization support vector regression and grey wolf optimized support vector regression models through the experimental data. The results show that the improved grey wolf algorithm has stronger global search ability, faster convergence speed and better stability, and the proposed prediction model has strong advantages in accuracy and stability, which can provide better decision reference for coal spontaneous combustion fire prediction and warning in coal mines.

The Homogeneous Gas-Phase Formation Mechanism of PCNs from Cross-Condensation of Phenoxy Radical with 2-CPR and 3-CPR: A Theoretical Mechanistic and Kinetic Study.

Chlorophenols (CPs) and phenol are abundant in thermal and combustion procedures, such as stack gas production, industrial incinerators, metal reclamation, etc., which are key precursors for the formation of polychlorinated naphthalenes (PCNs). CPs and phenol can react with H or OH radicals to form chlorophenoxy radicals (CPRs) and phenoxy radical (PhR). The self-condensation of CPRs or cross-condensation of PhR with CPRs is the initial and most important step for PCN formation. In this work, detailed thermodynamic and kinetic calculations were carried out to investigate the PCN formation mechanisms from PhR with 2-CPR/3-CPR. Several energetically advantageous formation pathways were obtained. The rate constants of key elementary steps were calculated over 600~1200 K using the canonical variational transition-state theory (CVT) with the small curvature tunneling (SCT) contribution method. The mechanisms were compared with the experimental observations and our previous works on the PCN formation from the self-condensation of 2-CPRs/3-CPRs. This study shows that naphthalene and 1-monochlorinated naphthalene (1-MCN) are the main PCN products from the cross-condensation of PhR with 2-CPR, and naphthalene and 2-monochlorinated naphthalene (2-MCN) are the main PCN products from the cross-condensation of PhR with 3-CPR. Pathways terminated with Cl elimination are preferred over those terminated with H elimination. PCN formation from the cross-condensation of PhR with 3-CPR can occur much easier than that from the cross-condensation of PhR with 2-CPR. This study, along with the study of PCN formation from the self-condensation 2-CPRs/3-CPRs, can provide reasonable explanations for the experimental observations that the formation potential of naphthalene is larger than that of 1-MCN using 2-CP as a precursor, and an almost equal yield of 1-MCN and 2-MCN can be produced with 3-CP as a precursor.

Combustion and Emission Study of Ethanol Blended Fuels in IC Engines

Abstract: As the most attractive heat engines, internal combustion engines are widely applied for various applications worldwide. These engines convert the chemical energy of the fuel to mechanical energy by the combustion phenomenon, which causes fuel to burn through fuel-air interaction and produce exhaust emissions. Spark ignition and compression ignition are two main categories of these engines differing in combustion mechanism. The conventional fuels of the noted engines are gasoline and diesel. With the population increase and the industrialization of societies, the use of internal combustion engines has become dramatically greater, causing several problems. Air pollution resulting from fuel combustion could be stated as one of the challenges that leads to the temperature rise of the earth and climate changes. The other problem is limited fossil fuels consumed by these engines. Additionally, health issues can be threatened by polluted air. Hence, renewable fuels were introduced as a vital key to overcome the obstacles. Biogas, liquefied petroleum gas, hydrogen, and alcohol are of well-known eco-friendly fuels. Among them, alcohol has drawn extensive attention due to its specific physical and chemical properties. Ethanol as alcohol with a high octane number, oxygen content, and low carbon to hydrogen ratio is a proper candidate to be used as an alternative fuel in internal combustion engines. Herein, the effect of ethanol on combustion and emission procedures is briefly reviewed. Moreover, the ethanol blends' effectiveness as a renewable fuel internal combustion engine is discussed. Furthermore, the measure of hydrocarbons, carbon monoxide, and oxides of nitrogen emissions is compared with the values created by pure gasoline/diesel combustion to analyze the emissions produced as pollution using ethanol blends. Keywords: Internal Combustion Engine, Combustion, Emission, Renewable Fuel, Ethanol Blend

Facile green synthesis of semiconductive ZnO nanoparticles for photocatalytic degradation of dyes from the textile industry: A kinetic approach

One-pot, facile and green synthesis of zinc oxide nanoparticles are synthesized using cow dung as fuel by combustion procedure. The synthesized material is characterized by using various techniques such as XRD, FTIR, UV, FESEM, and EDX. To assess the photocatalytic efficacy of the as-synthesized material, harmful cationic and anionic dyes such as methylene blue (MB) and alizarin red S (AZ) dyes, respectively, are selected as benchmark dyes. The influence of light source, dye concentration, photocatalyst dosage, and pH value on the efficiency of photocatalyst and kinetics of photodegradation are systematically studied. The photodegradation results revealed that the synthesized ZnO NPs exhibited removal efficiency of MB and AZ dyes upon irradiation with UV light. Concisely, the removal efficacy of the ZnO NPs under UV light irradiation exhibited an MB and AZ degradation of 99.9% and 96.8%, respectively. A reasonable photo-catalytic mechanism for the high photodegradation efficacy of MB and AZ dyes by the prepared photocatalyst is also proposed. The green fabricated photocatalyst is promising material and could be applied for waste-water remediation and other ecological applications.

Effect of lattice strain on structure, morphology, electrical conductivity and magneto-optical and catalytic properties of Ni-doped Mn3O4 nano-crystallites synthesized by microwave route

Ni-doped Mn3O4 nanoparticles (NPs) were synthesized by a simple one-pot microwave combustion procedure utilizing urea as a fuel. X-ray diffraction, transmission electron microscopy (TEM), diffuse reflectance spectroscopy, Photoluminescence spectra, and vibrating sample magnetometer. The particle size and the crystalline size measured from the HR-TEM monographs and XRD study suggest the similarity of the data collected from these two measurements. Photoluminescence (PL) spectra demonstrated increased luminescence amplitude with increased Ni concentration. Thus, the present study determines the time required for 4-nitrophenol yellow to colorless by Ni-doped Mn3O4 and Mn3O4 samples.

Facile synthesis and characterization of Fe2O3 nanoparticles using L-lysine and L-serine for efficient photocatalytic degradation of methylene blue dye

In this work, Fe 2 O 3 nanoparticles, abbreviated as OL and OS, were facilely synthesized by the combustion procedure using L-lysine and L-serine as organic fuels, respectively. Also, the OL and OS samples were identified using different instruments such as Raman spectrometer, FT-IR spectrophotometer, UV–Vis spectrophotometer, XRD, HR-TEM, BET surface area, and FE-SEM. The XRD confirmed that the mean grain size of OL and OS samples is 42.23 and 33.16 nm, respectively. The HR-TEM images confirmed that irregular, hexagonal, and spherical shapes, have an average diameter of 39.13 and 34.28 nm, were observed in the OL and OS samples, respectively. The BET surface area of the OL and OS samples is 16.20 and 28.34 m 2 /g, respectively. Additionally, the OL and OS samples were accomplished for the photocatalytic degradation of methylene blue dye in the absence and presence of hydrogen peroxide. The % degradation of 45 mL of 25 mg/L of methylene blue dye in the case of using OL and OS samples in the absence of hydrogen peroxide is 55.23 and 63.64 % after 120 min, respectively. Also, in the presence of hydrogen peroxide, the % degradation in the case of using OL and OS samples is 100 % after 35 and 25 min, respectively.

Onset of Oblique Detonation Waves for a Cavity-Based Wedge

To shorten the ignition length of the wedge-induced oblique detonation wave, a geometric setup in which the leading and aft wedges are connected by a cavity is proposed. High-resolution viscous computations to solve the reactive Reynolds-averaged Navier–Stokes equations have been performed, which examine the onset and evolution of combustion and flow configuration with premixed mixtures of inflow Mach numbers ranging from 4.0 to 6.0. The unreactive flowfield of the cavity-based wedge is analogous to that of a sole cavity with the exclusion of shock/shock interaction downstream. For and 5.0, no sustainable oblique detonation wave is achieved, and the flame holds in the cavity and near-wall area of the aft wedge; however, a short-lived detonation wave triggered by the shock focuses is observed during the combustion procedure with . For , nearly direct detonation initiation of postshock occurs, and an oblique detonation wave is established above the fore edge of the cavity. Unexpectedly, a delayed ignition downstream contributes to the development of a recirculation zone, which results in a detached oblique detonation wave for .

A new approach in the one-step synthesis of α-MnO2 via a modified solution combustion procedure.

Manganese oxides were synthesized systematically via the solution combustion procedure using two kinds of fuels, namely glycine and urea. The influences of the type of fuel and the fuel ratio were deeply investigated to explain the phase evolution and morphology of the product. The synthesized nanostructured powder was characterized by X-ray diffraction, particle size analysis, and FESEM. Furthermore, the thermodynamic aspects of all the synthesis reactions were studied by the calculation of the adiabatic temperature. Various manganese oxides, such as MnO, Mn3O4, Mn2O3, and MnO2, were obtained by varying the fuel ratio from 0.15 to 2. It was found that decreasing the fuel ratio promoted the formation of MnO2 by declining the combustion temperature and reductive conditions of the system. However, α-MnO2 could be simply achieved by adding KNO3 in a modified solution combustion process under fuel-lean conditions. Further heat treatment of the product was found to increase the crystallinity of the α-MnO2 nanoparticles.

Structural and photometric investigations of green emanating Er3+ activated SrGd2Al2O7 nanophosphors for solid state illumination applications

This study features structural and photometric aspects of a down-converted green emanating erbium (Er3+) activated nanophosphor synthesized via a versatile and environmentally benign urea aided solution combustion procedure. The powder X-ray diffraction pattern (PXRD) of optimal sample SrGd1.96Er0.04Al2O7 studied qualitatively by employing the Rietveld refinement practice, disclosed the tetragonal crystal phase with space group 14/mmm (139), consisting grains of size 50.03 nm. Surface morphology and grain size of nanopowders were well investigated by electron microscopy practices like scanning electron microscopy (SEM) and high resolution transmission electron microscopy (HRTEM). SEM micrograph gave clear insight that Er3+ doped nanophosphors possess slightly agglomerated particles with pores, voids and cracks due to high pressure breakout of gases while combustion synthesis. TEM and SEM images revealed the size of nanoparticles in the ambit of 40–60 nm which was in coherence with that obtained from the scherrer's equation, while the inter-fringes distance corresponding to diffraction plane (116) was calculated to be 0.27 nm from the HRTEM image. The desired nanophosphor showed brilliant green emission with an intense peak at 551 nm attributed to 4S3/2 → 4I15/2 transition of Er3+ ions, as analyzed through photoluminescent (PL) emission spectra monitored via near ultraviolet excitation wavelength (381 nm) with an optimal doping concentration of 2.0 mol%. Advanced photometric features like CIE color coordinates (0.3017, 0.6043), CCT (6032K), and color purity (76.52%) confirmed their green glow and are found to be in harmony with standard green emission. The study offers a luminous cool green emanating component for the fabrication of WLEDs and advanced optoelectronic appliances.

ZnO/La2O3/NiO based ternary heterostructure nano-photocatalyst: Preparation, characterization and its application for the degradation of methylene blue

ZnO based ternary heterostructure ZnO/(X wt%)La2O3/NiO (X = 1%, 3% and 5% of La2O3) nanoparticles were successfully synthesized employing waste curd as fuel by facile one-pot combustion procedure. The composition, morphology and structure of the fabricated heterostructures were characterized using various microscopic and spectroscopic instruments including using XRD, FTIR, UV–Visible, EDX, FESEM andHRTEM analysis. To evaluate the photo-catalytic degradation efficacy of the prepared ternary nanocomposite, textile dye methylene blue (MB) was selected as benchmark reaction under solar irradiation. The influence of several catalytic variables including light source, catalyst loading, photocatalyst dose, MB concentration, irradiation time, and pH value on the photo-degradation performance was systematically examined and the results were discussed. The results reveal that 3 wt% La2O3 doped ternary ZnO/NiO photocatalyst exhibits excellent performance towards the photocatalytic degradation of the studied dye. The ternary heterostructure i.e. ZnO/(3 wt%) La2O3/NiO exhibits superior MB degradation efficacy of 98% at 150 min under natural solar irradiation. The obtained observations conclude that the prepared nanocomposite exhibits pH dependent photo-catalytic efficacy, and for better results, concentrations of dye and photocatalysts have to be kept in a specific range. Moreover, different light sources have also been applied and their results are compared.

Collaborative optimization of fuel composition and operating parameters of gasoline compression ignition (GCI) engine in a wide load range

Through the integration of three-dimensional computational fluid dynamics (CFD) simulation and genetic algorithm, the operating parameters and fuel composition of a gasoline compression ignition (GCI) engine were simultaneously explored in the full load range. The blends of n-heptane, iso-octane, and toluene were utilized as the substitute for real gasoline fuels, in which toluene can efficiently diminish the heat release rate so that excessively high ringing intensity (RI) can be avoided at high load by extending combustion duration. The synergistic effects of fuel properties and operating parameters on combustion and emissions were analyzed. In addition, the fuel composition requirements of GCI combustion were further discussed. The optimization results indicate that the collaborative optimization can achieve low nitrogen oxides (NOx) emissions, near-zero soot emissions, and satisfactory fuel consumption under the GCI strategy. The combustion procedure was dominated by initial temperature and pressure at low load, and the effect of fuel characteristics is strengthened with higher load. The optimal combustion phasing of the GCI engine is postponed with the increase of load, which can enhance the temperature and fuel stratifications in the cylinder to prevent unacceptable RI. To minimize NOx emissions, a high proportion of n-heptane is preferred at low load and the contents of iso-octane and toluene approach to zero. Fuel research octane number (RON) has an inconspicuous impact on GCI at low load, and the fuel with higher RON can perform well at low load, except for the slightly higher NOx and soot emissions for high RON fuels. With the increase of load, the proportion of n-heptane decreases, which is compensated by the higher proportion of iso-octane. At high load, a certain amount of toluene is required, and high soot emissions are the main factor to limit the adoption of low RON fuels. Overall, GCI engine can utilize the fuel with RON between 70 and 80 in a wide load range.

Facile synthesis of Al2O3/Sodium dodecyl sulphate/2-aminophenol composite for efficient removal of Pb(II), Cd(II), and Co(II) ions from aqueous media

ABSTRACT In this paper, Al2O3 nanoparticles with an average crystallite size of 35.56 nm are facilely synthesised using the combustion procedure in the presence of glutamine as organic fuel. Besides, Al2O3/Sodium dodecyl sulphate/2-aminophenol composite is synthesised and applied as a novel adsorbent for the removal of Pb(II), Cd(II), and Co(II) ions from aqueous media. The synthesised samples are characterised using several tools such as X-ray diffraction (XRD), elemental analysis, Fourier-transform infrared spectroscopy (FT-IR), and field emission scanning electron microscopy (FE-SEM). In the case of Al2O3, the XRD peaks, which were appeared at 2θ of 38.11, 46.21, and 66.72°, are attributed to the (311), (400), and (440) planes of γ-Al2O3, respectively. In the case of Al2O3/Sodium dodecyl sulphate/2-aminophenol composite, the existence of a wide XRD peak at 2Ɵ = 25° confirming that the crystal assembly of Al2O3 combined or interfered over amorphous organic surroundings. Elemental analysis of the Al2O3/Sodium dodecyl sulphate/2-aminophenol composite displayed that the % C, % H, and % N are 17.23, 4.21, and 1.58%, respectively. The maximum adsorption capacity, which was obtained from Langmuir isotherm, of the composite towards Pb(II), Cd(II), and Co(II) ions is 119.19, 101.21, and 86.51 mg/g, respectively. The best description for the experimental results is given by the pseudo-second-order kinetic model and Langmuir adsorption isotherm. Also, the thermodynamic parameters confirmed that the removal of studied ions is spontaneous, exothermic, and chemical. After three adsorption-desorption cycles, 25%V/V (Methanol/HNO3) is the suitable desorbing medium needed for the recapture of the adsorbed metal ions on the composite. Hence, the synthesised composite could be reutilised without notable losses of its effectiveness.

Straightforward Synthesis of Mn3O4/ZnO/Eu2O3-Based Ternary Heterostructure Nano-Photocatalyst and Its Application for the Photodegradation of Methyl Orange and Methylene Blue Dyes.

Zinc oxide-ternary heterostructure Mn3O4/ZnO/Eu2O3 nanocomposites were successfully prepared via waste curd as fuel by a facile one-pot combustion procedure. The fabricated heterostructures were characterized utilizing XRD, UV–Visible, FT-IR, FE-SEM, HRTEM and EDX analysis. The photocatalytic degradation efficacy of the synthesized ternary nanocomposite was evaluated utilizing model organic pollutants of methylene blue (MB) and methyl orange (MO) in water as examples of cationic dyes and anionic dyes, respectively, under natural solar irradiation. The effect of various experimental factors, viz. the effect of a light source, catalyst dosage, irradiation time, pH of dye solution and dye concentration on the photodegradation activity, was systematically studied. The ternary Mn3O4/ZnO/Eu2O3 photocatalyst exhibited excellent MB and MO degradation activity of 98% and 96%, respectively, at 150 min under natural sunlight irradiation. Experiments further conclude that the fabricated nanocomposite exhibits pH-dependent photocatalytic efficacy, and for best results, concentrations of dye and catalysts have to be maintained in a specific range. The prepared photocatalysts are exemplary and could be employed for wastewater handling and several ecological applications.

Facile synthesis and characterization of ZnO nanoparticles for studying their biological activities and photocatalytic degradation properties toward methylene blue dye

Lately, attention to combustion synthesis has been encouraged owing to being cost-effective, rapid, and produces samples with low crystallite sizes and/or different morphology. So, in this paper, for the first time, ZnO nanoparticles were facilely fabricated utilizing the combustion procedure using L-arginine, L-valine, and L-alanine as organic fuels. Besides, the fabricated ZnO samples were recognized using different tools such as FT-IR, XRD, FE-SEM, HR-TEM, and UV–Vis. The XRD patterns show that the mean crystallite size of ZnO samples, which were fabricated operating L-arginine, L-valine, and L-alanine fuels, is 25.24, 31.11, and 35.65 nm, respectively. The HR-TEM images approved that the ZnO samples, which were fabricated operating L-arginine, L-valine, and L-alanine fuels, are composed of irregular, hexagonal, and sphere shapes with an average diameter of 22.46, 34.57, and 40.29 nm, respectively. The EDX patterns display peaks at 1.0 and 8.6 KeV for Zn. Also, there are peaks at 0.6 KeV for O. The values of the energy gap for the ZnO samples, which were fabricated operating L-arginine, L-valine, and L-alanine fuels, are 3.30, 2.88, and 2.63 eV, respectively. The photocatalytic degradation process is an important water treatment method due to its effectiveness in producing hydroxyl free radicals which able to degrade numerous dyes. So, the fabricated ZnO samples were examined for the photocatalytic degradation of methylene blue dye along with biological activity against some strains of bacteria. Furthermore, the maximum percent of degradation of 50 mL of 10 mg/L methylene blue dye under UV irradiations is 54.69, 41.34, and 30.76% after 90 min exploiting the ZnO samples which were fabricated operating L-arginine, L-valine, and L-alanine fuels, respectively. Also, % degradation of methylene blue dye under UV irradiations in the presence of hydrogen peroxide is 100% after 70 min using the ZnO sample which was fabricated operating L-arginine fuel. Moreover, the fabricated ZnO products show high bactericidal activity against Staphylococcus aureus, Listeria monocytogenes, and Enterococcus faecalis. Additionally, the fabricated ZnO products show moderate bactericidal activity against Bacillus cereus and Salmonella typhimurium.

Machine Elements and Design Fundamental

The Mechanical Engineering essence is the understanding of all the available resources, their effective utilization, and making use of the law of nature to help, gain and benefit the entire humanity. Mechanical Engineering is the applied science using scientific knowledge and procedures as the means to accomplish a specific practical and useful results. It is related to the sense that involves a proper understanding of all the scientific principles and effectively applying them to attain the designated goal. The machine design in mechanical engineering is the most crucial section of engineering, and it deals with the design, conception, refinement, development of machines and component application together with the mechanical apparatus of every kind.In the professional engineering, the main concern is to obtain the requisite solutions to all the practical problems in the machinery production. The solutions should reflect the knowledge, understanding and application of the underlying technology and science. However, normally the mere understanding is not sufficient. The related empirical knowledge together with engineering judgment become the most prerequisite. For instance, no scientist can entirely understand electricity. However, it does not prevent any electrical engineer from creating highly useful and functional electrical devices. Likewise, no scientist can fully understand metal fatigues and combustion procedures, yet, the mechanical engineers utilize the knowledge and insight available to generate highly useful and functional combustion engines. When more scientific solutions are accessible, engineers can devise better explanations and clarifications to practical problems. This study tries to analyze and evaluate the perception and usefulness of AM- additive manufacturing systems and technologies to understand machine elements, product design and its development.

The impact of using pure ethanol additives on gasoline fuel with respect to SI engine emissions

A major problem in the gasoline engine operation process under heavy-duty conditions is the knocking phenomenon, noises produced in the combustion chamber during the combustion procedure as a consequence of the pre-ignition process. These occur effect of the high temperature of the air, which causes fuel to ignite without additional activation energy (spark). The octane number for gasoline fuel measures the resistance of the fuel to such auto-ignition. Experimental work was done in this study to study the influence of adding pure ethanol to conventional Iraqi gasoline fuel at percentages varying from 10% to 90% in 10% increments by volume, with various fuel properties like density, octane number, viscosity, fuel vapour pressure, and flash point temperature, measured and compared. Ethanol additives were found to increase fuel density, flash point temperature, viscosity, and octane number while reducing fuel vapour pressure. The engine utilised in the trials was a single-cylinder, gasoline engine, naturally aspirated and air-cooled. The experimental outcomes for specific fuel consumption showed decreases of up to 29% at the 90% volumetric percentage of ethanol in conventional gasoline fuel, and emissions of engine NOX, CO, and HC decreased by 67. 7%, 69%, and 61%, respectively, However, CO2 emissions increased.

Molten shell-activated, high-performance, un-doped Li4SiO4 for high-temperature CO2 capture at low CO2 concentrations

Lithium orthosilicate (Li4SiO4) represents a potential class of high-temperature sorbents for CO2 capture in power plants and sorption enhanced methane reforming to produce H2. However, conventional wisdom suggests that pure Li4SiO4 should have extremely slow sorption kinetics at realistic low CO2 concentrations. Here, we report the opposite result: using a simple and cost-effective glucose-based mild combustion procedure, an unusually efficient and pure form of Li4SiO4 (MC-0.6) was synthesized to achieve a maximum uptake capacity of 35.0 wt% at 580 °C for CO2 concentrations under 15 vol% and maintained this capacity over multiple cycles. The characterization results showed that highly porous nano-agglomerate-like (50–100 nm) morphologies were apparent and ensured a rapid surface-sorption of CO2. In this process, a macroporous nano-sized Li2SiO3 cover on the melt layer of Li2CO3 was identified for the first time. This special structure appeared to accelerate the transportation of CO2 and the diffusion of Li+ and O2− through a molten layer enhancing contact with CO2. Thus, the sample MC-0.6 reduced both the surface-sorption and diffusion kinetics dependence on low CO2 concentrations. Rather than use traditional approaches (controlled morphologies combined with doping), we have demonstrated that the slow kinetics can be overcome simply by a controlled morphologies strategy, which opens up a new direction for the synthesis of high-performance Li4SiO4 sorbents.

Performance analysis of bio-fuel blends for clean energy production: Thermogravimetric analysis

Use of local Lignite as a fuel for clean energy generation play an increasingly important role in the domestic industry. Lignite is considered as the lowest rank of coal because of its comparatively low carbon content, high volatile and sulphur contents. The thermal and kinetics characteristics of lignite and rice husk and their blends (in different ratios) were evaluated by using iso-thermal and non-isothermal conditions. Therefore, it was challenging to use lignite separately as fuel. Keeping this situation in context, the thermal behaviour of lignite, rice husk, and their blends throughout pyrolysis and combustion procedures, was examined for their possible usage as a sustainable, substitute and clean energy resource. The experiments were conducted at a heating rate of 40 °C/min, from room temperature to 950 °C. The de-volatilisation of rice husk happened earlier in oxygen-enriched circumstances. Besides, these blends presented diverse ignition performance in different atmospheres. The kinetic factors of the blends established enhanced ignition features, by analysing the thermo-gravimetric results. The activation energy showed that the blend has a significant amount of energy, which is suitable for the industrial combustion process. It was also shown that PL50%-LRH50% have the extreme retention time, activation energy, carbon contents, calorific value and low volatile and Ash contents, as compared to the other blends, which concluded that this combination is the finest blend for the clean production of energy.

Combustion of liquid ethanol in an innovatory vortex-tube combustor with Self-evaporating and edge-like flame properties

The combustion performance of a novel self-evaporating vortex-tube combustor for liquid fuel proposed in this study was experimentally explored by taking liquid ethanol as fuel. The new combustor was developed via installing a double-layer self-evaporating tube made of stainless steel and copper into the center of a localized stratified vortex-tube combustor. The evaporation temperature and rate of liquid fuel can be controlled by adjusting the flow rate of cooling air flowing through the tube interlayer. The effects of global equivalence ratio and fuel flow rate on the stability limit, pressure fluctuation, flame configuration, and NOx and CO emissions were investigated. The results corroborate that the novel vortex-tube combustor can achieve full evaporation of ethanol up to 30 mL/min, corresponding to a heat output of 10.57 kW. The localized stratified distribution of species formed in the combustor results in an edge-like tubular flame structure and correspondingly a wide stability limit, which enables stable ultra-lean combustion with the global equivalence ratio as low as 0.22. The pressure fluctuation amplitudes are always less than 800 Pa throughout the entire operating map. The combustor can achieve low NOx and CO emissions below 18 ppm under appropriate conditions. The high-steady combustion procedure makes the ultra-lean combustion conducted, whilst the evaporating of liquid fuel can also decrease the temperature of the post-flame zone, then reducing the formation of thermal NOx. Furthermore, the high-temperature post-flame zone locates in the fuel-rich region with high concentrations of CO and H2, which can further inhibit the production of NOx.