Evaluation of oxygenated n-butanol-biodiesel blends along with ethyl hexyl nitrate as cetane improver on diesel engine attributes

Sarma

Int. J. Environ. Sci. Technol.

2021

In recent years, disposal of used cooking oil has drawn everyone attention due to its detrimental and hazardous effects upon health and environment. However, used cooking oil has great potential to be a fuel supplement after its appropriate processing for biofuel formulation, globally. Attributed to the various advantages of microemulsion-based hybrid biofuel (MHBF) technique, the present experimental investigation has focused to investigate the effects of used cooking oil (UCO)-based hybrid microemulsion biofuel (UCOMHBF), added with 2-ethylhexyl nitrate (2-EHN) (cetane enhancer) upon performance, combustion and emission characteristics of a 4-stroke single-cylinder CI engine. 2-EHN was added in UCOMHBF (UCO (55%) (vol.%), anhydrous ethanol (E) (28%) (vol.%) and 2-butanol (B) (17%)) in proportion of 500 (UCOMHBF500), 1000 (UCOMHBF1000) and 1500 (UCOMHBF1500) ppm, respectively. The brake-specific fuel consumption (BSFC) of CI engine test rig for UCOMHBF1000 was found 8% lower than UCOMHBF and B100 and 2.5% higher for UCOMHBF1500, respectively. Combustion delay was observed with MHBFs w.r.t petrodiesel, but improved combustion was observed with up to 1000 ppm addition of 2-EHN in UCOMHBF at full load condition. Addition of 1500 ppm 2-EHN in UCOMHBF showed uncontrolled flame propagation at the end of the compression stroke which resulted in incomplete combustion during power stroke. 2-EHN addition in UCOMHBF has also lowered the mean of nitrogen (NO x ) in the range of 2.06-33.33% w.r.t petrodiesel. Hence, it can be concluded that UCOMHBF1000 has shown the superior characteristics from all other UCOMHBFs.

Section: Rate Of Pressure Rise (Ropr)mentioning

confidence: 90%

Section: Particle Size Analysis Of Ucomhbfmentioning

confidence: 99%

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Experimental investigation of 2-EHN effects upon CI engine attributes fuelled with used cooking oil-based hybrid microemulsion biofuel

Sarma

Int. J. Environ. Sci. Technol.

2021

“…Furthermore, W85 emitted 10% less CO (on average) compared to fossil diesel. The reduction in CO emission was presumably due to relatively higher oxygen content (Table6) and reduced viscosity of the WCO biodiesel which led to better combustion[51].…”

mentioning

confidence: 99%

Investigation of 2-butoxyethanol as biodiesel additive on fuel property and combustion characteristics of two neat biodiesels

Masera¹,

Hossain²,

Davies

et al. 2021

Renewable Energy

Neat biodiesels are not preferred for use in the compression ignition (CI) engines due to their high viscosities and related operational difficulties. This study investigated the fuel properties and combustion characteristics when 2-butoxyethanol additive was mixed separately with waste cooking oil biodiesel (W100) and rapeseed oil biodiesel (R100). Compared to neat biodiesels, the viscosities (at 40 ⁰C) of the W100 and R100 were reduced by 12.5% and 9.8% respectively, when they were blended separately with 15% 2-butoxyethanol. Four different samples such as W100, mixture of 85% W100 and 15% 2-Butoxyethanol (W85), R100, mixture of 85 % R100 and 15% 2-Butoxyethanol (R85) were tested in a multi-cylinder CI engine. The thermal efficiency of the W85 fuel was higher than fossil diesel by approximately 3.7%. Total combustion duration of the biodiesel-additive blends were shorter than neat biodiesels and fossil diesel. Biodiesel-additive blends provided approximately 6% higher in-cylinder peak pressures. At full load, W85 fuel gave up to 5.4% reduced NOx emissions than neat biodiesel. The CO, HC and smoke emissions were decreased by up to 36%, 100% and 79% respectively. The study concluded that 2-butoxyethanol could effectively be used as biodiesel additive to improve fuel property; and to achieve better combustion and reduced pollution.

“…One explanation for this was that the lower cetane number prolonged the ignition delay period and increased the time for fuel to evaporate, resulting in an increase in HC emissions. Imdadul et al [12] studied the effect of adding EHN to a biodiesel-n-butanol-diesel blended fuel on the engine performance of a single-cylinder naturally aspirated engine. The results showed that EHN improved the cetane number and accelerated the blending of gas air-fuel, so the mixture became inhomogeneous in the diffusion combustion zone and emitted high HC.…”

mentioning

confidence: 99%

Experimental Study of the Effect of Intake Oxygen Concentration on Engine Combustion Process and Hydrocarbon Emissions with N-Butanol-Diesel Blended Fuel

et al. 2019

This paper summarizes a study based on a modified, light, single-cylinder diesel engine and the effects of the physicochemical properties for n-butanol-diesel blended fuel on the combustion process and hydrocarbon (HC) emissions in the intake at a medium speed and moderate load in, an oxygen-rich environment (Coxy = 20.9-16%), an oxygen-medium environment (Coxy = 16-12%), and an oxygen-poor environment (Coxy = 12-9%). The results show that the ignition delay period is the main factor affecting the combustion process and it has a decisive influence on HC emissions. In an oxygen-medium environment, combustion duration affected by the cetane number is the main reason for the difference in HC emissions between neat diesel fuel (B00) and diesel/n-butanol blended fuel (B20), and its influence increases as the intake oxygen concentration decreases. In an oxygen-poor environment, in-cylinder combustion temperature affected by the latent heat of vaporization is the main reason for the difference in HC emissions between B00 and B20 fuels, and its influence increases as the intake oxygen concentration decreases. By comparing B20 fuel with diesel/n-butanol/2-ethylhexyl nitrate blended fuel (B20 + EHN), the difference in the ignition delay period caused by the difference in the cetane number is the main reason for the difference in HC emissions between B20 and B20 + EHN fuels in oxygen-poor environment, and the effect of this influencing factor gradually increases as the intake oxygen concentration decreases.Energies 2019, 12, 1310 2 of 17 turbocharged diesel engine. The results showed that the addition of n-butanol produces more HC emissions as compared with the pure diesel because of the slow evaporation and the high latent heat of vaporization of n-butanol blends over a 25% load at 3000 r/min. Rajesh Kumar et al. [4] studied the effects of the mixing iso-butanol, n-pentanol, n-hexanol, and n-octanol with diesel on the engine performance of a single-cylinder, four-stroke, naturally aspirated diesel engine. The results showed that the high HC emissions of iso-butanol-diesel blends was attributed to the dominative effect of the latent heat of evaporation over its cetane number. Using a turbocharged in-cylinder direct injection diesel engine, Ileri [5] studied the influence of adding 2-ethylhexyl nitrate (EHN) on the combustion and emission of a diesel-sunflower, oil-n-butanol blended fuel and diesel-sunflower, oil-1-pentanol blended fuel. The test results showed that, at all engine loads, the higher latent heat of vaporization of n-butanol and 1-pentanol leads to an increase in HC emissions compared to diesel. Armas et al. [6] investigated pollutant emissions from the New European Driving Cycle (NEDC) using ethanol-and butanol-diesel blends. The result showed that the latent heat of vaporization is an important factor in HC emissions, but the high combustion temperatures during the development of NEDC weakened the effect of the latent heat of vaporization as compared with the combustion in cold engine conditions. Atmanli, Yi...