Lower Brake Specific Fuel Consumption Research Articles

Optimization of design and fuel parameters of a DI CI engine through desirability function and RSM for lower emissions and clean environment

In the present investigation an attempt was made to control the NOx and smoke emission of a DI CI engine by simultaneously varying design and fuel factors of the engine. Four design factors and four fuel factors with three levels were chosen and test matrix were designed as per L18 orthogonal array. Experiments were conducted with different combinations of chosen design and fuel factors as per the designed test matrix and the responses (NOx, smoke and brake specific fuel consumption (BSFC)) were recorded for 18trials. Significance and interaction of the tested factors were obtained through analysis of variance technique. Desirability function through RSM approach was employed to investigate the optimum combination of tested factor levels for lower NOx, smoke and BSFC. At optimum level of factors both NOx and smoke emissions of the engine was reduced without any increase in its BSFC. This investigation reveals that combination of fuel and design factors have the ability to reduce the NOx and smoke simultaneously without any compromise on engine performance.

Fuel consumption and NOx emissions optimization of a marine natural gas engine with lean-burn and reformed exhaust gas recirculation strategies

Marine natural gas (NG) engines have received extensive attention in the shipping industry. To further improve the performance of the lean-burn engine, the reformed exhaust gas recirculation (REGR) technology which can realize hydrogen-rich combustion and exhaust gas recirculation is considered. In the present study, a comprehensive investigation on the performance of the marine NG engine with the exhaust gas-fuel reformer (the closed-loop system) was performed by GT-power software. Firstly, the characteristics of the reformer under different excess air ratios (λ) and reformate addition rates (Rre) were analyzed at specific M/O (the volume ratio of CH4 to O2 in the reformer inlet). Then, effects of the lean-burn strategy (the increase of λ) and REGR strategy (the increase of Rre) on combustion, performance and emission of the engine were studied. Moreover, the multi-objective genetic algorithm was utilized to obtain the optimal operating parameters (λ, Rre and M/O) of the closed-loop system. The results showed that the combustion duration is prolonged, the peak in-cylinder pressure and the NOx emissions are reduced with the increase of λ and Rre, but the brake specific fuel consumption (BSFC) is slightly increased. Despite the energy loss during the reforming process, BSFC of the engine with REGR strategy is lower than that of the lean-burn strategy due to the improvement of the engine thermal efficiency. Taking IMO’s Tier Ⅲ NOx standards and lowest BSFC as the optimization objects, the closed-loop system is recommended to work at λ = 1.41–1.49, Rre = 12–14%, and M/O = 1.0–1.2.

Split injection strategy control map development through prediction-based calibration approach to improve the biodiesel-fuelled diesel engine characteristics.

Karanja oil blended with diesel acts as a good alternative for a CI engine due to its low emission and high oxygen content as compared to pure diesel which leads to the non-toxic and biodegradable nature of the fuel. The objective of this project is to enhance the performance and emission characteristics of a diesel engine that runs on biofuel by accurately calibrating its fuel injector control parameters. To achieve this goal, the project focuses on creating optimal split injector control maps using a novel global model-based calibration approach that considers the entire range of engine speed-load conditions. To develop the model, the experimentation was conducted using the I-optimal design of the experiment technique. To establish a relationship between the calibration parameters and engine performance parameters based on experimental data, the study employed response surface methodology (RSM). With the support of a developed model and multi-objective optimization approach under equivalent importance to performance and emissions, the optimum injector control points are derived. For the developed engine map for 20% KBD (Karanja bio-diesel)-blended fuel, the BTE (brake thermal efficiency) reaches up to 30% and lower BSFC (brake specific fuel consumption) of 0.37 kg/kW-hr. After optimization, the split injector control map showed significant improvements over the un-optimized map. At 19 Nm and 3000 rpm, the optimized map resulted in a 31.36% increase in BTE and a 29.31% decrease in BSFC. Moreover, the optimization successfully balanced the trade-off between reducing nitrogen oxide (NOx) emissions and smoke emissions. However, the optimized fuel map for 20% KBD-blended fuel shows slightly lower performance compared to diesel fuel. While the optimization process led to a decrease in smoke emissions about 22.3%, it also resulted in elevated NOx emissions about 9.83% when compared to diesel fuel. Furthermore, emissions of CO and HC are reduced by 12.8% and 19.2%, respectively, in an optimized control map of 20% KBD-blended fuel compared to un-optimized map.

Experimental studies on performance and emission measures of a 4-stroke compression ignition engine using palm bio-diesel blended with N-butanol

The enormous consumption of energy, stiff increase in oil prices, and customary fuel degradation contribute to massive fuel crises in most of the developed countries. Despite the mild energy disaster and extreme environmental regulations, Diesel engines pose a vital option for automobile vehicles. However, the increased Diesel emissions and the higher labor cost associated to cut down the same make the Bio-diesels blended with N-butanol a better option to resolve the fossil gasoline problems in the future. Hence, the present study highlights the performance and emission measures of a 4-stroke Compression Ignition (CI) engine using N-butanol additive (solvent) with Palm Bio-diesel. Experiments are conducted (i) with only Diesel (ii) with Palm Bio-diesel (in percentages of 10, 15, and 20) mixed with Diesel, and (iii) with N-butanol additive (considered 10% only) to the mixture of Palm Bio-diesel (in percentages of 10, 15, and 20) and Diesel. Experimental analyses are carried out in the same engine using an eddy current dynamometer. The effect of various performance parameters like Brake specific fuel consumption (BSFC), Brake thermal efficiency (BTE), Brake specific energy consumption (BSEC), and Exhaust gas temperature (EGT) on the engine load (varying between 0 and 16 N) is evaluated. On the other hand, different regulated emission measures like Smoke opacity, Nitrogen Oxide (NOx), Carbon Monoxide (CO), Carbon Dioxide (CO2), and Hydrocarbons (HC) are also evaluated at the same engine loads. The idea is to identify the feasibility and potential benefits of these biofuel blends in the CI engine. Adding 10% N-butanol to Bio-diesel, the HC, CO2, CO, and smoke opacity are reduced to a greater extent. The NOx emissions are also controlled to a larger extent using N-butanol. Again, the BA10 (10% Palm Bio-diesel, 10% N-butanol, and 80% Diesel) has a 2% higher BTE and a 1.33% lower BSFC compared to Diesel and B10 (10% Palm Bio-diesel, and 90% Diesel). The addition of N-butanol to Diesel also helps in reducing the fuel density, kinematic viscosity, and cetane value of blended fuels and can be used as a substitute fuel for Diesel engines.

Effect of C4 alcohol and ester as fuel additives on diesel engine operating characteristics

Due to their numerous advantages, diesel engines remain the primary energy source for heavy machinery. In the present experimental study, the effect of oxyfuel type, oxygen content and blend volume on diesel engine performance, combustion and emission characteristics has been investigated. Experiments were carried out on seven fuel blends using a 4-stroke, single cylinder, direct injection combustion ignition (CI) engine at a constant speed of 2000 rpm and varying loads. Four-carbon alcohol (n-butanol) and ester (ethyl ethanoate) were separately blended with pure diesel (D100) at three blending ratios. For each fuel type, two blends were prepared to contain an approximate oxygen mass content of 2.2 % and 4.1 %, then a third blend containing 15 % additive volume ratio was also formulated. All tested blends had minimal effect on in-cylinder pressure and heat release rate (HRR). At low loads, up to 20.9 % rise in brake specific fuel consumption (BSFC) was recorded but EE15 (15 % ethyl ethanoate, 85 % diesel) achieved 15.35 % lower BSFC at 60 % load. NOx emissions reduced for all blends, with n-butanol blends achieving 30.6 % less NOx emissions compared to D100. However, CO emissions increased by up to 37.6 % for n-butanol and 32.9 % for ethyl ethanoate. Considering engine stability, all blends were found to have a stable engine operation. Between the oxyfuel types, EE10.65 (10.65 ethyl ethanoate, 89.35 % diesel) has slightly superior emissions characteristics at equal fuel mass flow rate. Both fuel additives are suitable for CI engine at low blending ratios.

Applied Intelligent Grey Wolf Optimizer (IGWO) to Improve the Performance of CI Engine Running on Emulsion Diesel Fuel Blends

Water-in-diesel (W/D) emulsion fuel is a potential alternative fuel that can simultaneously lower NOx exhaust emissions and improves combustion efficiency. Additionally, there are no additional costs or engine modifications required when using W/D emulsion fuel. The proportion of water added and engine speed is crucial factors influencing engine behavior. This study aims to examine the impact of the W/D emulsion diesel fuel on engine performance and NOx pollutant emissions using a compression ignition (CI) engine. The emulsion fuel had water content ranging from 0 to 30% with a 5% increment, and 2% surfactant was employed. The tests were performed at speeds ranging from 1000 to 3000 rpm. All W/D emulsion fuel was compared to a standard of pure diesel in all tests. A four-cylinder, four-stroke, water-cooled, direct-injection diesel engine test bed was used for the experiments. The performance and exhaust emissions of the diesel engine were measured at full load and various engine speeds using a dynamometer and an exhaust gas analyzer, respectively. The second purpose of this study is to illustrate the application of two optimizers, grey wolf optimizer (GWO) and intelligent grey wolf optimizer (IGOW), along with using multivariate polynomial regression (MPR) to identify the optimum (W/D) emulsion blend percentage and engine speed to enhance the performance, reduce fuel consumption, and reduce NOX exhaust emissions of a diesel engine operating. The engine speed and proportion of water in the fuel mixture were the independent variables (inputs), while brake power (BP), brake thermal efficiency (BTE), brake-specific fuel consumption (BSFC), and NOx were the dependent variables (outcomes). It was experimentally observed that utilizing emulsified gasoline generally enhances engine performance and decreases emissions in general. Experimentally, at 5% water content and 2000 rpm, the BSFC has a minimal value of 0.258 kJ/kW·h. Under the same conditions, the maximum BP of 11.6 kW and BTE of 32.8% were achieved. According to the IGWO process findings, adding 9% water to diesel fuel and running the engine at a speed of 1998 rpm produced the highest BP (11.2 kW) and BTE (33.3%) and the lowest BSFC (0.259 kg/kW·h) and reduced NOx by 14.3% compared with the CI engine powered by pure diesel. The accuracy of the model is high, as indicated by a correlation coefficient R2 exceeding 0.97 and a mean absolute error (MAE) less than 0.04. In terms of the optimizer, the IGWO performs better than GWO in determining the optimal water addition and engine speed. This is attributed to the IGWO has excellent exploratory capability in the early stages of searching.

Fuel efficiency and emissions reduction of hydroxy added gasoline fuel using HydroBoost technology

In the present work, using the HydroBoost technology, performance and emission characteristics of HHO added Gasoline is investigated. HydroBoost technology offers longevity to cell and increases the efficiency as it requires less power to break the bonds of water. Achieving good emission characteristics using HydroBoost technology is still unexplored. In the present work, following the EPA protocols, a comprehensive analysis of Total Hydrocarbon (THC), Methane (CH4), NOx, CO2, MPG emissions in four phases is performed. It is shown that harmful gas emissions are reduced in HHO added Gasoline in comparison to only Gasoline fuel. The stoichiometric air-fuel mixture has been achieved in the present work. BSFC (Brake Specific Fuel Consumption) is reduced by up to 11% and the overall emissions of HHO added gasoline are reduced by up to 13% for CO2, up to 72% for Total Hydrocarbons, up to 69% for Methane, up to 48% for NOx in relation to bare Gasoline fuel. The present technology enables Hydroxy gas to be produced on board the IC vehicle without creating an undesirable amount of parasitic loss or hazard, which can be immediately deployed to lower both BSFC and emissions including greenhouse gasses such as CO2.

Evaluating the hythane/water diesel emulsion dual fuel diesel engine characteristics at various pilot diesel injection timings

In this experimental study was mostly focused on the impact of pilot diesel fuel Injection Timing (IT) on a dual fuel engine. The diesel engine was renewed in to dual fuel mode by injecting the Hythane20 (20% hydrogen and 80Methane) from the inlet manifold and Water in Diesel Emulsion 10 (10% water and 90% diesel WiDE10) as a primary fuel. Initially, the engine was operated at a constant Compression Ratio CR (18.5) and standard IT of 23°bTDC. Further, carried out the experimentation with retarded IT of 20°bTDC and Advanced IT of 26°bTDC. From the obtained results observed the higher Brake Thermal Efficiency (BTE) for 26°bTDC than the other. It is around 3.1 % higher and 6.45% lower Brake Specific Fuel Consumption (BSFC) than the diesel. It was also reported drastic reduction in smoke opacity 27.45% than the diesel fuel operation.

Investigation on a diesel engine fueled with hydrogen‐compressed natural gas and Kusum seed biodiesel: Performance, combustion, and emission approach

AbstractThe objective of the present study is to evaluate the performance, combustion, and emission characteristics of a compression‐ignition engine using hydrogen‐compressed natural gas (HCNG)‐enriched Kusum seed biodiesel blend (KSOBD20). The flow rate of HCNG was set at 5, 10, and 15 liters per minute (lpm), and the injection pressure was varied in the range of 180–240 bar. Brake thermal efficiency (BTE) and brake‐specific fuel consumption (BSFC) were improved when HCNG was added to the KSOBD20. Combustion characteristics, namely, cylinder pressure (CP) and net heat release rate (NHRR), were also improved. Emissions of carbon monoxide (CO), hydrocarbons (HC), and smoke were also reduced, with the exception of nitrogen oxides (NOx). The higher injection pressure (240 bar) had a positive effect on operating characteristics. At an injection pressure of 240 bar, for KSOB20 + 15 lpm HCNG, the highest BTE and the lowest BSFC were found to be 32.09% and 0.227 kg/kWh, respectively. Also, the CP and NHRR were 69.34 bar and 66.04 J/deg. CO, HC, and smoke levels were finally reduced to 0.013%, 47 ppm, and 9%, respectively, with increased NOx levels of 1623 ppm. For optimum results in terms of engine characteristics, the fuel combination KSOBD20 + 15 lpm HCNG at fuel injection pressure 240 bar is recommended. Thus, HCNG‐enriched KSOBD20 can be used as an alternative fuel in diesel engines without requiring any modifications to increase performance and reduce emissions.

Effect of α-aluminium oxide nano additives with Sal biodiesel blend as a potential alternative fuel for existing DI diesel engine

The increasing demand, rapid consumption, price increase, limited reserves, and environmental concern due to pollution produced by conventional fossil fuel (diesel & gasoline) are a few reasons why biofuels need to be explored. The present paper employs a systematic methodology to examine the performance of a 20% volumetric blend of Sal biodiesel (S20) blended with diesel using α-aluminium oxide (α-Al2O3) nanoparticles (NP) as additives and is compared with a diesel under like circumstances. The central composite design, Box-Behnken design (BBD) based response surface methodology, and desirability tests are used in the organized experiments on a diesel engine configuration to facilitate calibration. The created multivariate regression model yields all of the best engine inputs. Interaction effects are used to determine the most influential element by observing the interaction of two distinct input factors on a single response. According to the desirability tests, the highest estimated desirability was 0.579; the optimal input parameters found are 21°bTDC injection timing (IT), 238 bar injection pressure (IOP), 17 compression ratio (CR), and 74 ppm concentration of α-Al2O3NP, estimated the optimized response of brake thermal efficiency (BHTE) 31.18%, brake specific fuel consumption (BSFC) 0.2975 kg/kWh, carbon monoxide (CO) 0.0887%, hydrocarbon (HC) 31 ppm, oxide of nitrogen (NOx) 677 ppm, and smoke level 54.92%. These predicted values were validated with experimental results, and errors were within the range. The nanoparticle combination sample offers improved brake thermal efficiency (BTHE) and lower BSFC rate than the S20 while testing for the optimal parametric condition. Graphical abstract [Formula: see text]

Variable Valve Strategy Evaluation for Low-Load Operation in a Heavy-Duty Gasoline Compression Ignition Engine

By harnessing gasoline’s low reactivity for partially premixed combustion promotion, gasoline compression ignition (GCI) combustion shows the potential to produce markedly improved NOx-soot trade-off with high fuel efficiency compared to conventional diesel combustion. However, at low-load conditions, gasoline’s low reactivity poses challenges to attaining robust combustion with low unburned hydrocarbons (UHC) and carbon monoxide (CO) emissions. Increasing the in-cylinder charge temperature by using variable valve actuation (VVA) can be an effective means to address these challenges. In this numerical investigation, VVA strategies, including (1) early exhaust valve opening (EEVO), (2) positive valve overlap (PVO), and (3) exhaust rebreathe (ExReb), were investigated at 1375 RPM and 2 bar brake mean effective pressure in a heavy-duty GCI engine using a market-based gasoline with a research octane number (RON) of 93. The total residual gas level was kept over 50% to achieve an engine-out NOx target of below 1.5 g/kWh. For a complete engine system analysis, one-dimensional (1-D) system-level modeling and three-dimensional (3-D) computational fluid dynamics (CFD) analysis were close-coupled in this study. Performance of the VVA strategies was compared in terms of in-cylinder charge and exhaust gas temperatures increase versus brake-specific fuel consumption (BSFC). The EEVO strategy demonstrated in-cylinder charge and exhaust temperature increase up to 130 and 180 K, respectively. For similar in-cylinder charge temperature gains, the ExReb strategy demonstrated 11% to 18% lower BSFC compared to the EEVO strategy. This benefit primarily originated from a more efficient gas-exchange process. The PVO strategy, due to the valve–piston contact constraint, required excessive exhaust back-pressure valve (BPV) throttling for hot residuals trapping, thereby incurring higher BSFC compared to ExReb. In addition, the ExReb strategy demonstrated the highest potential for exhaust temperature increase (up to 673 K) among the three strategies. This was achieved by ExReb’s maximum air-fuel ratio reduction from high internal residuals mass and BPV throttling. Finally, the ExReb profile was optimized in terms of the peak lift, the duration, and the location for maximizing the fuel-efficiency potential of the strategy.

Comparative Studies of Piston Crown Coating with YSZ and Al2O3·SiO2 on Engine out Responses Using Conventional Diesel and Palm Oil Biodiesel

In this study, the effect of a thermal barrier coating with yttria-stabilized zirconia (YSZ) and aluminum silicate (Al2O3·SiO2) alongside an NiCrAl bond coat on the engine performance and emission analysis was evaluated by using conventional diesel and pure palm oil biodiesel. These materials were coated on the piston alloy via plasma spray coating. The findings demonstrated that YSZ coating presented better engine performances, in terms of brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) for both fuels. The piston with YSZ coating materials achieved the highest BTE (15.94% for diesel, 14.55% for biodiesel) and lowest BSFC (498.96 g/kWh for diesel, 619.81 g/kWh for biodiesel). However, Al2O3·SiO2 coatings indicated better emission with lowest emissions of NO, CO, and CO2 for both diesel and biodiesel. For the uncoated piston, the results indicated that the engine clocked the highest torque and power, especially on diesel fuel due to the high viscosity and low caloric value, and it recorded the lowest hydrocarbon emission due to the complete combustion of fuel in the engine. Hence, it was concluded that the YSZ coating could lead to better engine performance, while Al2O3·SiO2 showed promising results in terms of greenhouse gas emission.

Experiment analysis and computational optimization of the Atkinson cycle gasoline engine through NSGA Ⅱ algorithm using machine learning

This paper is pioneered in developing digital twins by GT-Power software and multi-objective evolutionary optimization (MOEO) using NSGA II algorithm for an Atkinson cycle gasoline engine under China VI emissions standards. Firstly, an experimental investigation is conducted and relevant experimental data is obtained. Based on this, the corresponding 1D GT-Power simulation model is established and calibrated according to the obtained test data. Secondly, the four decision variables including the spark advance angle (SA), exhaust gas recirculation (EGR) rate, exhaust variable valve timing (VVT-E) and intake variable valve timing (VVT-I) are input into the simulation model, the optimal values of the decision variables will be determined via MOEO to minimize NOx emissions and the brake specific fuel consumption (BSFC). Thirdly, based on the data obtained from the scanning test, a machine learning method is used to build an engine performance prediction model through the support vector machine (SVM) regression algorithm. The inputs (control parameters obtained from the optimization process) including SA, EGR, VVT-I and VVT-E are imported to predict the performance output of the engine. The results show that under the engine control parameters obtained by the NSGA II algorithm, the simulation values of engine performance parameters have been greatly optimized, the decreasing extent of fuel consumption is about 5.0%, besides, the decreasing extent of NOx is about 70%. What is more, the increased EER and EEE is up to 6.21% and 2.26%, respectively. And then most of the predicted values obtained by machine learning have been optimized. For BSFC, in general, the simulation value and the predicted value are in good agreement at the smaller value, indicating that the simulation model and the regression prediction model basically achieve the same value at the lower BSFC of the engine. For NOx, the simulated and predicted values have all been optimized. Furthermore, the method and platform developed in this paper will help to carry out a series of related work in the field of vehicle energy flow distribution and optimization when changing different control strategies and optimization methods in the future. Besides, the above work provides a reliable theoretical basis and digital model support for the development of energy-saving and efficient Atkinson cycle engines, which further drives the application of Atkinson cycle engines in new energy vehicles.

RSM-Based Parameter Optimization of Compression Ignition Engine Fueled with Diesel Blended with Two Biofuels: Rice Bran and Karanja

The threat of depletion of fossil fuels, extensively used in transport sector, is promoting the research in the field of alternative fuels. Biofuels possess properties close to that of diesel, but being viscous, used as blend with diesel in compression ignition (CI) engines. The current work explores the mixing of two biofuels, karanja oil and rice bran oil, in diesel (designated as RK20) and to observe the performance of CI engine. The blend was made by mixing the oils in the proportion of 10:10:80 (karanja oil, rice bran oil and neat diesel (ND), respectively). The test rig used to conduct the investigation was a double-cylinder, turbocharged and water-cooled direct injection CI engine having constant speed of 1800 rpm and fixed compression ratio of 18.5:1. The injection parameters were varied to optimize the performance parameters of CI engine for the prepared blend of biofuel. The optimized output parameters were brake specific fuel consumption (BSFC) and brake power (BP) of the CI engine. The ranges of injection timing (IT) and injection pressure (IP) were $${{15}\,^{\circ }}$$ – $${{28}^{\circ }}$$ btdc and 230–300 bar, respectively. Central composite design technique of response surface methodology was used for design of experiments. The results include the lowest BSFC at low IP and IT for both ND and RK20 blend, also comparable with each other. Maximum BP and minimum BSFC were predicted at $${{15}^{\circ }}$$ btdc and 230 bar IT and IP respectively for both RK20 blend and ND.

Evaluating the impact of using various biodiesel blends on the performance of diesel engine at variable load conditions

Recently, researchers use various types of alternative fuels, for diesel engines. Previous studies, reveals that biodiesel with renewable origin, is the most promising alternative fuel, with less impact on the environment. The objective of this paper, is to determine experimentally, the impact of using different biodiesel blends, extracted from Sun flower, Palm, and Corn oils, on the performance on diesel engine. The engine was operated at variable load and fixed speed. The following main parameters were determined: Torque, Brake power, Brake Specific Fuel Consumption (BSFC), Brake thermal efficiency, Fuel consumption, and Exhaust temperature. Results show that when all the biodiesels were used as a fuel to the engine, the engine has lower BSFC and exhaust temperature, and higher brake thermal efficiency, than when using pure diesel as fuel for the engine. This implies that using the biodiesel blends is more economically than using pure diesel as a fuel for the engine. In addition, it was concluded that using all these blends produces less NOx emissions.

Experimental investigation of using kerosene-biodiesel blend as an alternative fuel in diesel engines

Researchers are seeking alternative ways to deal with conventional fuels depletion and global warming. Biodiesel appears as one of the most candidate alternatives in this regard. The present work deals with biodiesel produced by transesterification of sunflower oil. The produced biodiesel was further mixed with kerosene to obtain a blend between new and traditional fuels. The physicochemical properties of the bio-fuel blended with kerosene have been tested in the laboratory maintaining different ASTM standards. In this study, blends of biodiesel and kerosene were tested on TQ small engine test set (TD200). BK60 (biodiesel 60 vol. % and kerosene 40 vol. %), BK45 (biodiesel 45 vol. % and kerosene 55 vol. %), BK30 (biodiesel 30 vol. % and kerosene 70 vol. %) and BK15 (biodiesel 15 vol. % and kerosene 85 vol. %) were tested. Three mixing speeds were used in the tests, namely; 1000 rpm, 2000 rpm, and 3000 rpm at constant high load of 80%. The performance parameters studied included; brake thermal efficiency (BTE) and brake specific fuel consumption (BSFC). Regarding the emissions, carbon monoxide (CO), hydrocarbons (HC), and oxides of nitrogen (NOx) were also recorded. Results showed that the new blends produce higher BTE and lower BSFC than the conventional kerosene and biodiesel.

Generation of biodiesel from industrial wastewater using oleaginous yeast: performance and emission characteristics of microbial biodiesel and its blends on a compression injection diesel engine.

Microbial-derived biodiesel was tested on a lab scale CI diesel engine for carrying out exhaust emission and performance characteristics. The performance, emission, and combustion characteristics of a single cylinder four stroke fixed compression ratio engine when fueled with microbial bio-diesel and its 10-30% blends with diesel (on a volume basis) were investigated and compared with conventional diesel. The bio-diesel was obtained from microbes which were grown by combining distillery spent wash with lignocellulosic hydrolysate at nutrient deprived conditions. The microbes consumed the wastes and converted the high strength waste water into lipids, which were trans-esterified to form bio-diesel. Testing of microbial bio-diesel blends with ordinary diesel at different loading pressures and the emission characteristics were compared. Results indicate that with increasing of the blends, reduction of HC and CO emissions were observed, whilst brake thermal efficiency maxed out at 20% blending. Further increase of blends showed a tendency of increasing of both emissions in the exhaust stream. The Brake Specific Fuel consumption was observed to decline with blending until 20% and then increased. The nitrogen oxide emissions, however, were found to increase with increasing blend ratios and reached a maximum at 20% blend. The escalation of HC, CO, CO2, and NOx emissions was also observed at higher blending ratios and higher engine loads. The performance studies were able to show that out of the three blends of biodiesel, 20% biodiesel blend was able to deliver the best of reduced hydrocarbon and carbon monoxide emissions, whilst also delivering the highest Brake thermal efficiency and the lowest Brake Specific Fuel consumption.

Induction of hydrogen, hydroxy, and LPG with ethanol in a common SI engine: a comparison of performance and emission characteristics

In this investigation, performance and emission characteristics for enhancing LPG, hydrogen, and hydroxy with E20 were evaluated for the understanding of which fuel combination performs better in a gasoline engine. In the upper sequence, hydroxy-hydrogen-LPG could perform best in terms of brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC). The induction of gaseous fuel improves CO, CO2, and HC emission but increases the NOx emission. More concisely, the enhancement of hydroxy with E20 shows the best engine performance for highest BTE while lowest BSFC as well as lowest exhaust emissions (CO, HC, except NOx).

Improvement of ternary fuel combustion with various injection pressure strategies in a toroidal re-entrant combustion chamber.

The present experimental work focuses on the influence injection pressure and toroidal re-entrant combustion chamber in a single cylinder diesel engine fuelled with ternary fuel (diesel-biodiesel-ethanol) blend. Ternary fuel (TF) is prepared by blending 70% diesel, 20% biodiesel, and 10% ethanol blends and its fuel properties were investigated and compared with diesel fuel. Since the physic-chemical properties of TF are well behind the diesel fuel, it is proposed to be blended with 20ppm alumina nano additives which act as an ignition enhancer and catalytic oxidizer. The resulting fuel mixture (TF + 20ppm alumina additive) is named as high performance fuel (HPF). Experimentations were conducted on HPF subjected to various injection pressures of 18MPa, 20MPa, 22MPa, and 24MPa respectively and are operated in toroidal re-entrant chamber geometry (TG) at an injection timing of 22 obTDC. From experimentation, it was identified that, for TG-HPF, higher injection pressure of 22MPa ensued highest BTE (Brake Thermal Efficiency) of 35.5% and lowest BSEC (Brake Specific Fuel Consumption) of 10.13MJ/kWh owing to the pooled effect of higher swirl formation, improved atomization enhanced evaporation rate, and better air-fuel mixing. Emission wise TG-HPF operated at 22MPa lowered the HC (hydrocarbon), CO (carbon monoxide), and smoke emissions by 18.88%, 7.19%, and 5.02%, but with marginally improved NOx (oxides of nitrogen) and CO2 (carbon dioxide) emissions by 3.92% and 3.89% respectively. In combustion point of view, it is observed that injection pressure increased the cylinder pressure, heat release rate (HRR), and cumulative heat release rate (CHRR) by 5.35%, 5.08%, and 3.38% respectively indicating improved combustion rate as a result of enhanced atomization, evaporation, and high turbulence inducement. Overall, it is concluded that operating the ternary fuel at 22MPa injection pressure at toroidal re-entrant combustion chamber results in improved performance and minimized emissions.

Mitigation of NOx emission using aromatic and phenolic antioxidant-treated biodiesel blends in a multi-cylinder diesel engine.

The present work analyzes the effect of antioxidants on engine combustion performance of a multi-cylinder diesel engine fueled with PB30 and PB50 (30 and 50 vol.% palm biodiesel (PB)). Four antioxidants namely N,N'-diphenyl-1,4-phenylenediamine (DPPD), N-phenyl-1,4-phenylenediamine (NPPD), 2(3)-tert-Butyl-4-methoxyphenol (BHA), and 2-tert-butylbenzene-1,4-diol (TBHQ) were added at concentrations of 1000 and 2000ppm to PB30 and PB50. TBHQ showed the highest activity in increasing oxidation stability in both PB30 and PB50 followed by BHA, DPPD, and NPPD respectively, without any negative effect on physical properties. Compared to diesel fuel, PB blends showed 4.61-6.45% lower brake power (BP), 5.90-8.69% higher brake specific fuel consumption (BSFC), 9.64-11.43% higher maximum in cylinder pressure, and 7.76-12.51% higher NO emissions. Carbon monoxide (CO), hydrocarbon (HC), and smoke opacity were reduced by 36.78-43.56%, 44.12-58.21%, and 42.59-63.94%, respectively, than diesel fuel. The start of combustion angles (SOC) of PB blends was - 13.2 to - 15.6 °CA BTDC, but the combustion delays were 5.4-7.8 °CA short compared to diesel fuel which were - 10 °CA BTDC and 11°CA respectively. Antioxidant fuels of PB showed higher BP (1.81-5.32%), CO (8.41-24.60%), and HC (13.51-37.35%) with lower BSFC (1.67-7.68%), NO (4.32-11.53%), maximum in cylinder pressure (2.33-4.91%) and peak heat release rates (HRR) (3.25-11.41%) than baseline fuel of PB. Similar SOC of - 13 to - 14 °CA BTDC was observed for PB blended fuels and antioxidants. It can be concluded that antioxidants' addition is effective in increasing the oxidation stability and in controlling the NOx emissions of palm biodiesel fuelled diesel engine.