Air pollution is a major issue affecting the health of millions of citizens, notably in cities where pollutants are concentrated. Low-temperature combustion is a promising route to reduce nitrogen ...oxides and smoke emissions from compression ignition engines. Reduction in emissions during low-temperature combustion is known, yet emissions using oxygenated biofuels are poorly known. Therefore, I tested the potential reduction in emissions using oxygenated biofuels during low-temperature combustion, in the reactivity-controlled compression ignition mode. Ethanol, a low-reactivity fuel, was inducted in the intake manifold at 10% and 20% levels on energy basis, whereas waste cooking oil biodiesel, a high-reactivity fuel, was injected directly inside the cylinder. Results show a reduction in emission of nitrogen oxides up to 60%, and of smoke up to 29%. Nonetheless, unburned hydrocarbons and carbon monoxide emissions increased up to 2% at full load for biodiesel with 20% ethanol induction, compared to neat diesel and biodiesel.
Indeed, the development of alternate fuels for use in internal combustion engines has traditionally been an evolutionary process in which fuel-related problems are met and critical fuel properties ...are identified and their specific limits defined to resolve the problem. In this regard, this research outlines a vision of lemongrass oil combustion characteristics. In a nut-shell, the combustion phenomena of lemongrass oil were investigated at engine speed of 1500rpm and compression ratio of 17.5 in a 4-stroke cycle compression ignition engine. Furthermore, the engine tests were conducted with partial premixed charge compression ignition-direct injection (PCCI-DI) dual fuel system to profoundly address the combustion phenomena. Analysis of cylinder pressure data and heat-release analysis of neat and premixed lemongrass oil were demonstrated in-detail and compared with conventional diesel. The experimental outcomes disclosed that successful ignition and energy release trends can be obtained from a compression ignition engine fueled with lemongrass oil.
•Analyzing the recent developments in pyrolysis processes of microalgae.•Mechanism of the various types of pyrolysis was summarized.•Biochemical composition was discussed in detail.•Microwave ...assisted pyrolysis has achieved more significance than other process.•Quality of the bio-oil in catalytic pyrolysis was higher than thermal pyrolysis.
Algae become reasonable feedstock in recent times for biofuel production as they are environmentally benign, sustainable and renewable biomass. Biofuels are produced from algal biomass by chemical, biochemical, and thermochemical methods. Among the thermochemical techniques, pyrolysis is a well-known method involving high temperature and high pressure to produce biochar and bio-oil from numerous algal biomasses. Therefore, this review was undertaken to collate and discuss different pyrolytic processes employed for the conversion of algal biomass into biochar and bio-oil production. At the outset, different pyrolysis methods slow pyrolysis, fast/flash pyrolysis, catalytic pyrolysis, microwave assisted pyrolysis and hydropyrolysis operated for the conversion of various microalgae and cyanobacteria into biochar and bio-oil were reviewed using copious literature. Further, challenges arisen out of using above-said pyrolysis methods were critically highlighted to pave the way to choose an appropriate pyrolysis method for obtaining desirable quantity and quality of bio-oil from algae.
In this study, the methods of converting raw non-edible oil into fuel for a diesel engine are discussed. Methods of preparation of nanoparticles like sol–gel, hydrothermal, homogenous addition and ...sonication methods are reviewed. The effect of nanoparticles doped with biodiesel–diesel blends on engine performance (specific fuel consumption and brake thermal efficiency) and combustion parameters (cylinder peak pressure rise and heat release rate) is presented. Moreover, the emission characteristics (carbon monoxide, unburned hydrocarbon, oxides of nitrogen and smoke emissions) on the use of biodiesel doped with nanoparticles are also discussed. This review indicates that nanoparticles doped with biodiesel diesel blends enhance rapid evaporation, provide better air–fuel interaction and allow more fuel to react with oxygen. As a result, DI-CI engine performance and combustion characteristics are improved and the emission levels are reduced. Therefore, it is one of the eco-friendly fuel technologies for DI-CI engine without any major modifications. Overall, this article would be beneficial for those doing research in the biodiesel manufacturing industries, nanotechnology and pollution control board.
Graphical abstract
Indeed, the engine industries have seen a tremendous growth in the research and development of new-age technologies over the past ten years or so. Even though a huge database is now available on ...present-day engine technologies, a skillful presentation of those data is a demanding task. At this count, an endeavor has been made here to brief the pros and cons of present-day engine technologies in an elusive manner. In a nut–shell, this article provides an extensive review of the primary principles that preside over the internal combustion engines design and operation, as well as a simplifying framework of new-age engine technologies has been organized and summarized in an elegant way to contribute to this pragmatic field.
This review discusses the sustainable transformation of low-quality hydrocarbon fuels, such as biomass-derived bio-oil, into valuable chemicals and clean fuels by introducing the concept of ..."methanotreating" that uses methane as a hydrogen source for the deoxygenation of bio-oils, thereby addressing environmental concerns associated with conventional hydrogen production. We explore the challenges of methane activation and its potential in biomass upgrading, highlighting the importance of catalyst selection and composition. Methanotreating is a promising and sustainable method for producing high-quality fuels and chemicals, with a deoxygenation performance of over 95%. This present work calls for further research and development in catalyst design and application to advance this innovative approach toward a greener and more efficient energy future.
In recent days, artificial neural network (ANN) is seen as a potential tool to perform mathematical modeling and prediction. In this analysis, the Levenberg–Marquardt backpropagation training ...algorithm is used to map the actual and the predicted value with the tansig activation function. The ANN model is developed to predict the engine performance and emission parameters for varying intake biogas–air mixture temperatures ranging from 55 ± 5 to 85 ± 5 °C under various load conditions. Around 70% of the total experimental data has been used for training, 15% for validation, and 15% for testing. The findings show higher coefficient of correlation (
R
,
R
2
and adjusted
R
2
values are in the range of 0.96–0.99) and lower mean square error (MSE = 0.0003515–0.00544501) for the developed ANN models. This study proves that ANN is an excellent tool for determining and optimizing the performance and emission parameters of compression ignition engines fuelled with alternative gaseous fuels.
Graphic abstract
Ionic liquids and their family known as deep eutectic solvents are non-flammable, nonvolatile, recyclable and environmentally friendly working fluids, making them suitable for use in various thermal ...systems. By adding nanoparticles to these fluids (through special physical and chemical approaches), one can augment their specifications (especially thermal conductivity). The current review presents, first, some of the latest studies on the thermophysical properties and electrical conductivity of ionanofluids (the mixture of nanoparticles and ionic liquids) and deep eutectic solvents-based nanofluids. Next, their applications in various fields such as solar energy, energy storage systems, and lubricants are reviewed. Finally, the current challenges for the development of these working fluids are listed and some recommendations have been presented for future works.
The present research work depicts the optimization of biodiesel production from used frying oil by response surface methodology. It was found that the optimal reaction conditions were 0.75% mass/mass ...catalyst concentration, 9:1 methanol-to-oil molar ratio, 60 min reaction time and 500 rpm stirrer speed. For these optimal conditions, biodiesel yield of 95.05 ± 0.15% was obtained. This work also attempts to study the effects of burned gases on the combustion characteristics of used frying oil biodiesel (B20) blend. The experiments were conducted in a single-cylinder, 4-stroke, water-cooled, direct injection compression ignition engine attached with electronically controlled exhaust gas recirculation system. The combustion studies were conducted with and without recirculation of 10% cooled and hot burned gases. The study showed that the overall effect of cooled burned gases was to reduce the maximum cylinder pressure by 3% and the maximum pressure rise rate by 2%. The re-circulated cooled burned gases also retarded the auto-ignition timing by 0.64°. On the other hand, the overall effect of hot exhaust gases on the combustion process is to increase the maximum pressure rise rate by 5% and advance the auto-ignition timing by 1.06°.
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