Assessment of energy performance and air pollutant emissions in a diesel engine generator fueled with water-containing ethanol–biodiesel–diesel blend of fuels

Biomass based oxygenated fuels have been identified as possible replacement of fossil fuel due to pollutant emission reduction and decrease in over-reliance on fossil fuel energy. In this study, 4 v% water-containing ethanol was mixed with (65–90%) diesel using (5–30%) biodiesel (BD) and 1 v% butanol as stabilizer and co-solvent respectively. The fuels were tested against those of biodiesel–diesel fuel blends to investigate the effect of addition of water-containing ethanol for their energy efficiencies and pollutant emissions in a diesel-fueled engine generator. Experimental results indicated that the fuel blend mix containing 4 v% of water-containing ethanol, 1 v% butanol and 5–30 v% of biodiesel yielded stable blends after 30 days standing. BD1041 blend of fuel, which composed of 10 v% biodiesel, 4 v% of water-containing ethanol and 1 v% butanol demonstrated −0.45 to 1.6% increase in brake-specific fuel consumption (BSFC, mL kW⁻¹ h⁻¹) as compared to conventional diesel. The better engine performance of BD1041 was as a result of complete combustion, and lower reaction temperature based on the water cooling effect, which reduced emissions to 2.8–6.0% for NO_x, 12.6–23.7% particulate matter (PM), 20.4–23.8% total polycyclic aromatic hydrocarbons (PAHs), and 30.8–42.9% total BaPeq between idle mode and 3.2 kW power output of the diesel engine generator. The study indicated that blending diesel with water-containing ethanol could achieve the goal of more green sustainability.     

Review of NOx reduction technologies in CI engines fuelled with oxygenated biomass fuels

Oxygenated fuels like biodiesel and alcohols have the potential to provide a reliable and a cost effective alternative to India's increasing future energy demands. They have a prospective future since they are renewable and can be produced easily in India's rural areas. Due to rapid industrialization and the increased number of vehicles on the road, the energy needs of the country are increasing rapidly. Oxygenated fuels can substantially replace the large demand for diesel to generate power for the industries and to fuel diesel engines of the vehicles. In spite of the many advantages of using them, most of the researchers have reported higher NO_x emissions, which is a deterrent to the market expansion of these fuels. The present program aims to review the NO_x emissions from the CI engines fuelled with oxygenated fuels. To meet the stringent emission norms, the various NO_x reduction technologies like use of additives, retarded fuel injection timing, biodiesel emulsion with water, and exhaust gas recirculation are reviewed. The results of the most effective and low cost technique of EGR in DI diesel engine fuelled with biodiesel–diesel blends and tri-compound oxygenated diesel fuel blends (ethanol–biodiesel–diesel fuel blends and methanol–biodiesel–diesel fuel blends) are presented.     

The impacts of compression ratio on the performance and emissions of ice powered by oxygenated fuels: A review

Energy sources are becoming a governmental issue, with cost and stable supply as the main concern. Oxygenated fuels production is cheap, simple and eco-friendly, as a well as can be produced locally, cutting down on transportation fuel costs. Oxygenated fuels are used directly in an engine as a pure fuel, or they can be blended with fossil fuel. The most common fuels that are conceded under oxygenated fuels are ethanol, methanol, butanol Dimethyl Ether (DME), Ethyl tert-butyl ether (ETBE), Methyl tert-butyl ether (MTBE) and biodiesel that have attracted the attention of researchers. Due to the higher heat of vaporization, high octane rating, high flammability temperature, and single boiling point, the oxygenated fuels have a positive impact on the engine performance, combustion, and emissions by allowing the increase of the compression ratio. Oxygenated fuels also have a considerable oxygen content that causes clean combustion. The aim of this paper was to systematically review the impact of compression ratio (CR) on the performance, combustion and emissions of internal combustion engines (ICE) that are operated with oxygenated fuels that could potentially replace petroleum-based fuels or to improve the fuel properties. The higher octane rating of oxygenated fuels can endure higher compression ratios before an engine starts knocking, thus giving an engine the ability to deliver more power efficiently and economically. One of the more significant findings to emerge from this review study was the slight increases or decreases in power when oxygenated fuel was used at the original CR in ICE engines. Also, CO, HC, and NOx emissions decreased while the fuel consumption (FC) increased. However, at higher CR, the engine performance increased and fuel consumption decreased for both SI and CI engines. It was seen the NOx, CO and CO₂ emissions of oxygenated fuels decreased with the increasing CR in the SI engine, but the HC increased. Meanwhile, in CI engine, the HC, CO and NOx decreased as the CR increased with biodiesel fuel.     

大豆生物柴油混合燃料性能试验研究

通过在R4105T柴油机上进行对比试验,分析了0#柴油／生物柴油、乙醇／生物柴油混合燃料以不同比例掺混时对柴油机动力性、经济性及碳烟排放特性的影响。研究结果表明：柴油机使用0#柴油／生物柴油混合燃料时动力性、碳烟排放量均有所下降,油耗率稍有上升;使用乙醇／生物柴油混合燃料时,碳烟排放量低于生物柴油,动力性、经济性随乙醇含量的不同而呈现不同的变化趋势。     

柴油机新型含氧燃料研究现状及进展

柴油机含氧燃料作为柴油的替代品和添加剂,可有效减少机动车尾气排放,缓解对石化燃料的依赖。因此,开发柴油机新型含氧燃料有着环保和节能的双重意义,是近年来研究热点。综述了国内外液态醚类燃料、醚酯类燃料、生物柴油等新型含氧燃料及其研究进展,介绍了它们的排放性能。     

Analysis of blended fuel properties and engine performance with palm biodiesel–diesel blended fuel

Depleting fossil fuel sources accompanied by continuously growing energy demands lead to increased interest in alternative energy sources. Blended biodiesel–diesel fuel has been approved as a commercial fuel at a low blending ratio. However, problems related to fuel properties are persistent at high blending ratios. Hence, in this study, the feasibility of biodiesel produced from palm oil was investigated. Characterization of blended fuel properties with increasing palm biodiesel ratio is conducted to evaluate engine performance test results. The qualifying of blended fuel properties was used to indicate the maximum blending ratio suitable for use in unmodified diesel engines according to the blended fuel standard ASTM D7467. The property test results revealed that blended fuel properties meet blended fuel standard requirements at up to 30% palm oil biodiesel. Furthermore, blending is efficient for reduction of the pour point from 14 °C for unblended biodiesel to less than 0 °C at a 30% biodiesel blending ratio. However, the energy content reduces by about 1.42% for each 10% increment of biodiesel. Engine test results demonstrated that there was no statistically significant difference for engine brake thermal efficiency among tested blended fuels compared to mineral diesel, and the lowest engine cyclic variation was achieved with blended fuel B30.     

Theoretical modeling and experimental studies on biodiesel-fueled engine

In recent years, much research has been carried out to find suitable alternative fuel to petroleum products. The use of renewable fuels like ethanol, biogas and biodiesel in diesel engines is significant in this context. The properties of biodiesel depend on the type of the vegetable oil used for the trans-esterification process. Experimental analysis of the engine with various biodiesel and its blends requires much effort and time. Hence, a theoretical model is developed to analyze the performance characteristics of the compression ignition engine fueled by biodiesel and its blends. In the present investigation, biodiesel is produced using unrefined rubber seed oil. A two-step trans-esterification process (i.e. acid–alkaline trans-esterification) is developed for the production of methyl-esters of rubber seed oil. The properties of this biodiesel are closely matched with those of diesel fuel. The performance tests are carried out on a C.I. engine using biodiesel and its blends with diesel (B20 and B100) as fuel. The effects of relative air-fuel ratio and compression ratio on the engine performance for different fuels are also analyzed using this model. The comparison of theoretical and experimental results are presented.     

Impact of Carbon Nanotubes and Di-Ethyl Ether as additives with biodiesel emulsion fuels in a diesel engine – An experimental investigation

In the current global energy scenario, fossil fuels face challenges with regards to exorbitant demand, environmental hazards and escalating costs. In this regard, the technical community is in quest for alternative resources. In this context, biodiesel fuel is potentially considered as alternative fuels for compression ignition engines. Hence, in this current investigation, biodiesel and biodiesel emulsions are prepared from a vegetable oil and further subjected for the blending with potential additives such as CNT (Carbon Nanotubes) and DEE (Di-Ethyl Ether) to improve the working attributes of the diesel engine. The entire investigation was carried out in five stages. In the first stage, both pure diesel and biodiesel (derived from jatropha oil) fuels were tested in the diesel engine to obtain baseline readings. In the second stage, water–biodiesel emulsion fuel was prepared in the proportion of 91% of biodiesel, 5% of water and 4% of emulsifiers (by volume). In the third stage, 50 ppm of CNT, 50 ml of DEE and combined mixture of CNT+DEE (50 ppm CNT+50 ml DEE) were mixed with the water–biodiesel emulsion fuel separately to prepare the CNT and DEE blended water–biodiesel emulsion fuels respectively. In fourth stage, the prepared emulsion fuels were subjected to stability investigations. In the fifth stage, all the prepared stable emulsion fuels were subjected for experimental testing in a diesel engine. It was observed that the CNT and DEE blended biodiesel emulsion fuels reflected better performance, emission and combustion attributes than that of pure diesel and biodiesel. At the full load, the brake thermal efficiency, NO and smoke emission of CNT+DEE fuels was 28.8%, 895 ppm and 36%, whereas it was 25.2%, 1340 ppm and 71% for pure diesel respectively. It was also observed that on adding CNT and DEE with the biodiesel emulsion fuels, the ignition delay was shortened and henceforth, the additive blended biodiesel emulsion fuels exhibited higher brake thermal efficiency and reduced emissions (NO, smoke) than that of pure diesel and biodiesel.     

Combined impact of varying biogas mass flow rate and rice bran methyl esters blended with diesel on a dual-fuel engine

ABSTRACT

For fetching day-to-day energy needs, current energy requirement majorly depends on fossil fuels. But ambiguous matter like abating petroleum products and expanding air pollution has enforced the experts to strive for another fuel which can be used as an alternative or reduce the applications of fossil fuels. Considering the issues, the main objective of the present study is to find the feasibility by using blends of rice bran oil biodiesel and diesel which are used as pilot fuels by blending 10% and 20% biodiesel in fossil diesel and biogas, introduced as gaseous fuel by varying its mass flow rate in a dual-fuel engine mode. An experimentation study was carried out to find the performance and emission parameters of the engine relative to pure diesel. The results were very much similar to the majority of researchers who used biodiesel and gaseous fuels in a dual-fuel engine. Brake specific fuel consumption (BSFC) of the engine was noticed to have increased, while brake thermal efficiency was on the lower side in dual fuel mode in comparison with regular diesel. In relation with conventional diesel, it was noticed that combined effect of rice bran methyl esters and varying mass flow rate of biogas showed a decrement in NO _x and smoke emissions, whereas HC and CO exhalations were on higher side when biogas and biodiesel were utilized collectively in dual-fuel engine. Hence, it was concluded that combination of blends of biodiesel and diesel and introduction of biogas in the engine can be a promising combination which can be used as a substitute fuel for addressing future energy needs.     

非直喷式增压柴油机燃用生物柴油的性能与排放特性

研究了非直喷式增压柴油机燃用柴油一生物柴油混合燃料的性能和排放特性。未对原机作任何调整和改动,研究了不同生物柴油掺混比例的混合燃料对功率、油耗、烟度和NOx排放的影响。结果表明：非直喷式柴油机燃用生物柴油后柴油机功率略有下降,油耗有所上升,烟度大幅下降,NOx排放增加明显。油耗、烟度和NOx的变化均与生物柴油掺混比例呈线性关系,合适的生物柴油掺混比例即可以保持柴油机的性能,又可有效地降低碳烟排放,且不引起NOx排放的显著变化。对于该增压柴油机,掺混生物柴油对外特性下的排放影响最大,影响最小的为标定转速下的负荷特性。不论是全负荷还是部分负荷,燃用生物柴油时低速下的烟度降低和NOx上升幅度均比高速时大,而同转速下高负荷时烟度降低和NOx上升更为明显。     

Hydrogen addition to tea seed oil biodiesel: Performance and emission characteristics

Compression ignition engines are the dominant tools of the modern human life especially in the field of transportation. But, the increasing problematic issues such as decreasing reserves and environmental effects of diesel fuels which is the energy source of compression ignition engines forcing researchers to investigate alternative fuels for substitution or decreasing the dependency on fossil fuels. The mostly known alternative fuel is biodiesel fuel and many researchers are investigating the possible raw materials for biodiesel production. Also, hydrogen fuel is an alternative fuel which can be used in compression ignition engines for decreasing fuel consumption and hazardous exhaust emissions by enriching the fuel. In this study, influences of hydrogen enrichment to diesel and diesel tea seed oil biodiesel blends (B10 and B20) were investigated on an unmodified compression ignition engine experimentally. In consequence of the experiments, lower torque and higher brake specific fuel consumption data were measured when the engine was fuelled diesel biodiesel blends (B10 and B20) instead of diesel fuel. Also, diesel biodiesel blends increased CO₂ and NO_x emissions while decreasing the CO emissions. Hydrogen enrichment (5 l/m and 10 l/m) was improved the both torque and brake specific fuel consumption for all test fuels. Furthermore, hydrogen enrichment reduced CO and CO₂ emissions due to absence of carbon atoms in the chemical structure for all test fuels. Increasing flow rate of hydrogen fuel from 5 l/m to 10 l/m further improved performance measures and emitted harmful gases except NO_x. The most significant drawback of the hydrogen enrichment was the increased NO_x emissions.     

Exhaust emission study on neat biodiesel and alcohol blends fueled diesel engine

In this study, neat biodiesel with octanol additive was employed in a diesel engine and its effects on engine emission were studied. The five fuels evaluated were neat palm kernal oil biodiesel, octanol blended with biodiesel by 10%, 20%, and 30% volume, and diesel. All the emissions are reduced by the addition of octanol in biodiesel in all loads owing to the higher oxygen concentration of air/fuel mixtures and improved atomization. Hence, it is concluded that the neat biodiesel and octanol blends can be employed as an alternative fuel for existing unmodified diesel engines owing to its lesser emission characteristics.     

生物含氧燃料成分对柴油机性能影响的试验研究

将占体积比80％的柴油分别掺混20％乙醇、20％生物柴油以及10％乙醇和10％生物柴油的混合物,连同纯柴油组成E20、B20、E10810和柴油共4种燃料,在一台4缸柴油机上进行燃烧、性能及排放特性试验研究。结果表明：含氧燃料成分的不同对折合油耗率基本不产生影响,但对燃烧和排放特性影响较大。发动机燃用E20的缸内最大爆发压力较柴油要大,B20、E10810较柴油要小;含氧燃料中生物柴油的加入使最大压力升高率减小,燃烧变得柔和;含氧燃料的放热时刻均落后于柴油的放热时刻。含氧燃料成分在中低负荷下对HC和CO的排放影响较大,随着含氧燃料中乙醇比例的增加HC和CO排放增加,在中高负荷下,3种含氧燃料的HC和CO排放基本相当;除了在2300r／min的中低负荷下含氧燃料的HC和CO排放较柴油高以外,其它工况下含氧燃料的HC和CO排放较柴油要低。含氧燃料成分不同对NOx排放的影响很小,3种含氧燃料的NOx排放都比柴油低。3种含氧燃料的碳烟排放较柴油要低,而且随含氧燃料中乙醇比例的增加,碳烟排放减小。     

A study on the performance and emission of a diesel engine fueled with Jatropha biodiesel oil and its blends

Biodiesel either in neat form or as a mixture with diesel fuel is widely investigated to solve the twin problem of depletion of fossil fuels and environmental degradation. The main objective of the present study is to compare performance, emission and combustion characteristics of biodiesel derived from non edible Jatropha oil in a dual fuel diesel engine with base line results of diesel fuel. The performance parameters evaluated were: brake thermal efficiency, brake specific fuel consumption, power output. As a part of combustion study, in-cylinder pressure, rate of pressure rise and heat release rates were evaluated. The emission parameters such as carbon monoxide, carbon dioxide, un-burnt hydrocarbon, oxides of nitrogen and smoke opacity with the different fuels were also measured and compared with base line results. The different properties of Jatropha oil after transestrification were within acceptable limits of standards as set by many countries. The brake thermal efficiency of Jatropha methyl ester and its blends with diesel were lower than diesel and brake specific energy consumption was found to be higher. However, HC, CO and CO₂ and smoke were found to be lower with Jatropha biodiesel fuel. NO_x emissions on Jatropha biodiesel and its blend were higher than Diesel. The results from the experiments suggest that biodiesel derived from non edible oil like Jatropha could be a good substitute to diesel fuel in diesel engine in the near future as far as decentralized energy production is concerned. In view of comparable engine performance and reduction in most of the engine emissions, it can be concluded and biodiesel derived from Jatropha and its blends could be used in a conventional diesel engine without any modification.     

柴油机清洁含氧燃料及其发展

本文对柴油机含氧燃料进行了综述,对醇类燃料、醚类燃料、生物柴油、酯类燃料、醚酯类清洁含氧燃料的理化性质、排放特性以及在柴油机上的应用进行了讨论,分析了含氧燃料的优缺点,指出了今后柴油机应用含氧燃料的趋势。     

Preparation,characterization, engine combustion and emission characteristics of rapeseed oil based hybrid fuels

In this study, hybrid fuels consisting of rapeseed oil/diesel blend, 1% aqueous ethanol and a surfactant (oleic acid/1-butanol mixture) were prepared and tested as a fuel in a direct injection (DI) diesel engine. The main fuel properties such as the density, viscosity and lower heating value (LHV) of these fuels were measured, and the engine performance, combustion and exhaust emissions were investigated and compared with that of diesel fuel. The experimental results showed that the viscosity and density of the hybrid fuels were decreased and close to that of diesel fuel with the increase of ethanol volume fraction up to 30%. The start of combustion was later than that of diesel fuel and the peak cylinder pressure, peak pressure rise rate and peak heat release rate were higher than those of diesel fuel. The brake specific fuel consumption (BSFC) of hybrid fuels was increased with the volume fraction of ethanol and higher than that of diesel. The brake specific energy consumption (BSEC) was almost identical for all test fuels. The smoke emissions were lower than those for diesel fuel at high engine loads, the NO_x emissions were almost similar to those of diesel fuel, but CO and HC emissions were higher, especially at low engine loads.     

柴油机清洁含氧燃料及其发展

本文对柴油机含氧燃料进行了综述,对醇类燃料、醚类燃料、生物柴油、酯类燃料、醚酯类清洁含氧燃料的理化性质、排放特性以及在柴油机上的应用进行了讨论,分析了含氧燃料的优缺点,指出了今后柴油机应用含氧燃料的趋势。     

Experimental study on the role of ethanol on performance emission trade-off and tribological characteristics of a CI engine

An experimental study of engine combustion, performance and emission characteristics using diesel–ethanol blends along with investigation of tribological effects of ethanol on engine oil was done in present work using 1-butanol as emulsifier. Thorough observations of diesel–ethanol miscibility resulted that 25% v/v ethanol is miscible with diesel using only 3% v/v emulsifier. Tribological effects of ethanol on engine oil were investigated by analyzing the engine oil samples through FT-IR (Fourier Transform Infrared Spectroscopy). Overall experimentation re-evaluated the potential of ethanol in reduction of NO_x, Soot and in-cylinder temperature with slight penalty for HC, CO and BSEC prominently at low load. All fuels produced more NO but lesser NO₂ at higher load satisfying Zeldovich mechanism. A comparative trade-off analysis was done in between NHC, Soot and BSEC to reflect the performance and emission characteristics at a time. Trade-off study revealed D78E20B02 (78% diesel 20% ethanol 2% butanol) as optimal blend among all fuels used in present work. FT-IR analysis depicted negligible variation in the compounds in engine oil samples for the specified operational period. Statistical analysis showed larger Coefficient of variation for D78E20B02 blend due to higher absorbance of a particular compound.     

Heat release and engine performance effects of soybean oil ethyl ester blending into diesel fuel

The engine performance impact of soybean oil ethyl ester blending into diesel fuel was analyzed employing heat release analysis, in-cylinder exergy balances and dynamometric tests. Blends with concentrations of up to 30% of soybean oil ethyl ester in volume were used in steady-state experiments conducted in a high speed turbocharged direct injection engine. Modifications in fuel heat value, fuel-air equivalence ratio and combustion temperature were found to govern the impact resulting from the addition of biodiesel on engine performance. For the analyzed fuels, the 20% biodiesel blend presented the best results of brake thermal efficiency, while the 10% biodiesel blend presented the best results of brake power and sfc (specific fuel consumption). In relation to mineral diesel and in full load conditions, an average increase of 4.16% was observed in brake thermal efficiency with B20 blend. In the same conditions, an average gain of 1.15% in brake power and a reduction of 1.73% in sfc was observed with B10 blend.     

Synergistic effect of hydrogen and waste lubricating oil on the performance and emissions of a compression ignition engine

The demand for energy is increasing every year. For a long time, fossil fuels have been used to satiate this energy demand. However, using hydrocarbon-based fossil fuels has led to an enormous rise of carbon dioxide levels in the atmosphere resulting in global warming. It is therefore necessary to look for alternatives to fossil fuels. The research carried out till date have shown biomass and waste-derived fuels as plausible alternatives to fossil fuels. The biomass feedstock includes jatropha oil, Karanja oil, cottonseed oil, and hemp oil among others and wastes include used cooking oil, used engine oil, used tire and used plastics etc. In this study, the authors aim to explore waste lubrication oil as a fuel for the diesel engine. The used lubrication oil was pyrolyzed and diesel-like fuel with 80% conversion efficiency was obtained. A blend of the fuel and diesel in the ratio of 80:20 on volume basis was prepared. Engine experiments at various load conditions was carried out with the blend. As compared to diesel, a 2% increase in thermal efficiency, 6.3%, 16.1% and 13.6% decrease in smoke, CO and HC emissions & 3.2% and 1.8% increase in NOx and CO₂ emission were observed at full load with the blend. With an aim to further improve the engine performance and reduce the overall emissions from the engine exhaust, a zero-carbon fuel namely gaseous hydrogen was inducted in the intake manifold. The flow rate of hydrogen was varied from 3 to 12 Litres per minute (LPM). As compared to diesel, at maximum hydrogen flow rate the thermal efficiency increased by 12.2%. HC, CO and smoke emissions decreased by 42.4%, 51.6% and 16.8%, whereas NOx emissions increased by 22%. The study shows that the combination of pyrolyzed waste lubricant and hydrogen were found to be suitable as a fuel for an unmodified diesel engine. Such fuel combination can be used for stationary applications such as power backups.