Influence of advanced injection timing on the performance and emissions of CI engine fueled with ethanol‐blended diesel fuel

Ethanol has been considered as an alternative fuel for diesel engines. On the other hand, injection timing is a major parameter that sensitively affects the engine performance and emissions. Therefore, in this study, the influence of advanced injection timing on the engine performance and exhaust emissions of a single cylinder, naturally aspirated, four stroke, direct injection diesel engine has been experimentally investigated when using ethanol‐blended diesel fuel from 0 to 15% with an increment of 5%. The original injection timing of the engine is 27° crank angle (CA) before top dead center (BTDC). The tests were conducted at three different injection timings (27, 30 and 33° CA BTDC) for 30 Nm constant load at 1800 rpm. The experimental results showed that brake‐specific energy consumption (BSEC), brake‐specific fuel consumption (BSFC), NO_x and CO₂ emissions increased as brake‐thermal efficiency (BTE), smoke, CO and HC emissions decreased with increasing amount of ethanol in the fuel mixture. Comparing the results with those of original injection timing, NO_x emissions increased and smoke, HC and CO emissions decreased for all test fuels at the advanced injection timings. For BSEC, BSFC and BTE, advanced injection timings gave negative results for all test conditions. Copyright © 2008 John Wiley & Sons, Ltd.     

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.     

Experimental investigations of performance and emissions of Karanja oil and its blends in a single cylinder agricultural diesel engine

An experimental investigation has been carried out to analyze the performance and emission characteristics of a compression ignition engine fuelled with Karanja oil and its blends (10%, 20%, 50% and 75%) vis-a-vis mineral diesel. The effect of temperature on the viscosity of Karanja oil has also been investigated. Fuel preheating in the experiments – for reducing viscosity of Karanja oil and blends has been done by a specially designed heat exchanger, which utilizes waste heat from exhaust gases. A series of engine tests, with and without preheating/pre-conditioning have been conducted using each of the above fuel blends for comparative performance evaluation. The performance parameters evaluated include thermal efficiency, brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC), and exhaust gas temperature whereas exhaust emissions include mass emissions of CO, HC, NO and smoke opacity. These parameters were evaluated in a single cylinder compression ignition engine typically used in agriculture sector of developing countries. The results of the experiment in each case were compared with baseline data of mineral diesel. Significant improvements have been observed in the performance parameters of the engine as well as exhaust emissions, when lower blends of Karanja oil were used with preheating and also without preheating. The gaseous emission of oxide of nitrogen from all blends with and with out preheating are lower than mineral diesel at all engine loads. Karanja oil blends with diesel (up to 50% v/v) without preheating as well as with preheating can replace diesel for operating the CI engines giving lower emissions and improved engine performance.     

Performance and emission analysis of compression ignition engine using biodiesels from Acid oil,Mahua oil,and Castor oil

Research on and use of biodiesels for engines is growing continuously in the present era. Compression ignition (CI) engine performance for biodiesels of blends B20 from Acid oil, Mahua oil, and Castor oil is experimentally investigated. The engine performance analysis in the form of brake‐specific fuel consumption, brake‐specific energy consumption, brake thermal efficiency (BTE), exhaust gas temperature (EGT), and air fuel ratio are compared with diesel as base fuel. Emission characteristics like CO, CO₂, NOx, and opacity are comparatively studied in detail for the considered biodiesels. The entire study is compared with the performance of engine when pure diesel is chosen as fuel. From the complete analysis it was observed that the BTE was higher for Acid oil and Mahua oil among the biodiesels used. And regarding CO emissions, Mahua oil showed lower effect than other biodiesels. Upto 6% increase in EGT of Mahua oil was obtained at no load and for other loads the percent reduced. For all the biodiesels the % enhancement in Co, CO₂, and NOx was more than 60% at highest load compared with diesel.     

Experimental investigation of control of NOx emissions in biodiesel-fueled compression ignition engine

Biodiesel is an alternative fuel consisting of the alkyl esters of fatty acids from vegetable oils or animal fats. Vegetable oils are produced from numerous oil seed crops (edible and non-edible), e.g., rapeseed oil, linseed oil, rice bran oil, soybean oil, etc. Research has shown that biodiesel-fueled engines produce less carbon monoxide (CO), unburned hydrocarbon (HC), and particulate emissions compared to mineral diesel fuel but higher NO_x emissions. Exhaust gas recirculation (EGR) is effective to reduce NO_x from diesel engines because it lowers the flame temperature and the oxygen concentration in the combustion chamber. However, EGR results in higher particulate matter (PM) emissions. Thus, the drawback of higher NO_x emissions while using biodiesel may be overcome by employing EGR. The objective of current research work is to investigate the usage of biodiesel and EGR simultaneously in order to reduce the emissions of all regulated pollutants from diesel engines. A two-cylinder, air-cooled, constant speed direct injection diesel engine was used for experiments. HCs, NO_x, CO, and opacity of the exhaust gas were measured to estimate the emissions. Various engine performance parameters such as thermal efficiency, brake specific fuel consumption (BSFC), and brake specific energy consumption (BSEC), etc. were calculated from the acquired data. Application of EGR with biodiesel blends resulted in reductions in NO_x emissions without any significant penalty in PM emissions or BSEC.     

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.     

Artificial Neural Network based prediction of performance and emission characteristics of a variable compression ratio CI engine using WCO as a biodiesel at different injection timings

Due to the increasing demand for fossil fuels and environmental threat due to pollution a number renewable sources of energy have been studied worldwide. In the present investigation influence of injection timing on the performance and emissions of a single cylinder, four stroke stationary, variable compression ratio, diesel engine was studied using waste cooking oil (WCO) as the biodiesel blended with diesel. The tests were performed at three different injection timings (24°, 27°, 30° CA BTDC) by changing the thickness of the advance shim. The experimental results showed that brake thermal efficiency for the advanced as well as the retarded injection timing was lesser than that for the normal injection timing (27° BTDC) for all sets of compression ratios. Smoke, un-burnt hydrocarbon (UBHC) emissions were reduced for advanced injection timings where as NO_x emissions increased. Artificial Neural Networks (ANN) was used to predict the engine performance and emission characteristics of the engine. Separate models were developed for performance parameters as well as emission characteristics. To train the network, compression ratio, injection timing, blend percentage, percentage load, were used as the input parameters where as engine performance parameters like brake thermal efficiency (BTE), brake specific energy consumption (BSEC), exhaust gas temperature (T_exh) were used as the output parameters for the performance model and engine exhaust emissions such as NO_x, smoke and (UBHC) values were used as the output parameters for the emission model. ANN results showed that there is a good correlation between the ANN predicted values and the experimental values for various engine performance parameters and exhaust emission characteristics and the relative mean error values (MRE) were within 8%, which is acceptable.     

Performance and emissions characteristics of Jatropha oil (preheated and blends) in a direct injection compression ignition engine

The scarce and rapidly depleting conventional petroleum resources have promoted research for alternative fuels for internal combustion engines. Among various possible options, fuels derived from triglycerides (vegetable oils/animal fats) present promising “greener” substitutes for fossil fuels. Vegetable oils, due to their agricultural origin, are able to reduce net CO₂ emissions to the atmosphere along with import substitution of petroleum products. However, several operational and durability problems of using straight vegetable oils in diesel engines reported in the literature, which are because of their higher viscosity and low volatility compared to mineral diesel fuel.In the present research, experiments were designed to study the effect of reducing Jatropha oil’s viscosity by increasing the fuel temperature (using waste heat of the exhaust gases) and thereby eliminating its effect on combustion and emission characteristics of the engine. Experiments were also conducted using various blends of Jatropha oil with mineral diesel to study the effect of reduced blend viscosity on emissions and performance of diesel engine. A single cylinder, four stroke, constant speed, water cooled, direct injection diesel engine typically used in agricultural sector was used for the experiments. The acquired data were analyzed for various parameters such as thermal efficiency, brake specific fuel consumption (BSFC), smoke opacity, CO₂, CO and HC emissions. While operating the engine on Jatropha oil (preheated and blends), performance and emission parameters were found to be very close to mineral diesel for lower blend concentrations. However, for higher blend concentrations, performance and emissions were observed to be marginally inferior.     

Direct injection diesel engine performance,emission, and combustion characteristics using diesel fuel,nonedible honne oil methyl ester,and blends with diesel fuel

Honne oil methyl ester (HOME) is produced from a nonedible vegetable oil, namely, honne oil, available abundantly in India. It has remained as an untapped new possible source of alternative fuel that can be used for diesel engines. The present research is aimed at investigating experimentally the performance, exhaust emission, and combustion characteristics of a direct injection diesel engine (single cylinder, water cooled) typically used in agricultural sector over the entire load range when fuelled with HOME and diesel fuel blends, HM20 (20% HOME + 80% diesel fuel)–HM100. The properties of these blends are found to be comparable with diesel fuel conforming to the American and European standards. The combustion parameters of HM20 are found to be slightly better than neat diesel (ND). For other blend ratios, these combustion parameters deviated compared with ND. The performance (brake thermal efficiency (BTE), brake‐specific fuel consumption, and exhaust gas temperature) of HM20 is better than ND. For other blend ratios, BTE is inferior compared with ND. The emissions (CO and SO) of HM20–HM100, throughout the entire load range, are dropped significantly compared with ND. Unburned hydrocarbon emissions of HM20–HM40, throughout the entire load range, is slightly decreased, whereas for other blend ratios, it is increased compared with ND. NO_x emissions of HM20, throughout the entire load range, is slightly increased, whereas for other blend ratios, it is slightly decreased. The reductions in exhaust emissions together with increase in BTE made the blend HM20 a suitable alternative fuel for diesel fuel and thus could help in controlling air pollution. Copyright © 2011 John Wiley & Sons, Ltd.     

The effect of clove oil and diesel fuel blends on the engine performance and exhaust emissions of a compression-ignition engine

Diesel engines provide the major power source for transportation in the world and contribute to the prosperity of the worldwide economy. However, recent concerns over the environment, increasing fuel prices and the scarcity of fuel supplies have promoted considerable interest in searching for alternatives to petroleum based fuels. Based on this background, the main purpose of this investigation is to evaluate clove stem oil (CSO) as an alternative fuel for diesel engines. To this end, an experimental investigation was performed on a four-stroke, four-cylinder water-cooled direct injection diesel engine to study the performance and emissions of an engine operated using the CSO–diesel blended fuels. The effects of the CSO–diesel blended fuels on the engine brake thermal efficiency, brake specific fuel consumption (BSFC), specific energy consumption (SEC), exhaust gas temperatures and exhaust emissions were investigated. The experimental results reveal that the engine brake thermal efficiency and BSFC of the CSO–diesel blended fuels were higher than the pure diesel fuel while at the same time they exhibited a lower SEC than the latter over the entire engine load range. The variations in exhaust gas temperatures between the tested fuels were significant only at medium speed operating conditions. Furthermore, the HC emissions were lower for the CSO–diesel blended fuels than the pure diesel fuel whereas the NO_x emissions were increased remarkably when the engine was fuelled with the 50% CSO–diesel blended fuel.     

6BTA 5.9 G2-1 Cummins engine performance and emission tests using methyl ester mahua (Madhuca indica) oil/diesel blends

Neat mahua oil poses some problems when subjected to prolonged usage in CI engine. The transesterification of mahua oil can reduce these problems. The use of biodiesel fuel as substitute for conventional petroleum fuel in heavy-duty diesel engine is receiving an increasing amount of attention. This interest is based on the properties of bio-diesel including the fact that it is produced from a renewable resource, its biodegradability and potential to exhaust emissions. A Cummins 6BTA 5.9 G2- 1, 158 HP rated power, turbocharged, DI, water cooled diesel engine was run on diesel, methyl ester of mahua oil and its blends at constant speed of 1500 rpm under variable load conditions. The volumetric blending ratios of biodiesel with conventional diesel fuel were set at 0, 20, 40, 60, and 100. Engine performance (brake specific fuel consumption, brake specific energy consumption, thermal efficiency and exhaust gas temperature) and emissions (CO, HC and NOx) were measured to evaluate and compute the behavior of the diesel engine running on biodiesel. The results indicate that with the increase of biodiesel in the blends CO, HC reduces significantly, fuel consumption and NOx emission of biodiesel increases slightly compared with diesel. Brake specific energy consumption decreases and thermal efficiency of engine slightly increases when operating on 20% biodiesel than that operating on diesel.     

Performance of jatropha oil blends in a diesel engine

Results are presented on tests on a single-cylinder direct-injection engine operating on diesel fuel, jatropha oil, and blends of diesel and jatropha oil in proportions of 97.4%/2.6%; 80%/20%; and 50%/50% by volume. The results covered a range of operating loads on the engine. Values are given for the chemical and physical properties of the fuels, brake specific fuel consumption, brake power, brake thermal efficiency, engine torque, and the concentrations of carbon monoxide, carbon dioxide and oxygen in the exhaust gases. Carbon dioxide emissions were similar for all fuels, the 97.4% diesel/2.6% jatropha fuel blend was observed to be the lower net contributor to the atmospheric level. The trend of carbon monoxide emissions was similar for the fuels but diesel fuel showed slightly lower emissions to the atmosphere. The test showed that jatropha oil could be conveniently used as a diesel substitute in a diesel engine. The test further showed increases in brake thermal efficiency, brake power and reduction of specific fuel consumption for jatropha oil and its blends with diesel generally, but the most significant conclusion from the study is that the 97.4% diesel/2.6% jatropha fuel blend produced maximum values of the brake power and brake thermal efficiency as well as minimum values of the specific fuel consumption. The 97.4%/2.6% fuel blend yielded the highest cetane number and even better engine performance than the diesel fuel suggesting that jatropha oil can be used as an ignition-accelerator additive for diesel fuel.     

Exploration of engine characteristics in a CRDI diesel engine enriched with hydrogen in dual fuel mode using toroidal combustion chamber

The impact of dual fuel (diesel/hydrogen) on different performance aspects of CRDI diesel engines is investigated in this study. Amongst the fuel alternatives for IC (internal combustion) engines, the research described in this study recommended hydrogen as the least polluting and renewable in the long term. A CNG-LPG injector feeds hydrogen into the intake manifold, while diesel injectors pump pilot diesel to a DI engine adapted to hydrogen and diesel (dual-fuel mode). By maintaining 5.2 KW of consistent IP (Indicated Power) and engine speed at 1500 ± 10 rotations per minute (RPM), the hydrogen energy was varied in the dual fuel at 0% (100% diesel), 6%, 12%, 18% and 24%. With the increase in H₂ energy proportion, a decrease (5.2% decrease at 24% HES) in the BSEC (brake specific energy consumption) and the engine's BTE (brake thermal efficiency) is improved (7.85% increase at 24% HES). When emissions are considered, indicated NO_x increased (3.42%) while indicated CO₂ (3.61%), CO (2.84%), and smoke (4.85%) decreased with an increase in the proportion of hydrogen. Along with this, it was noted that the peak HRR (heat release rate) of 69.8 J/deg and in-cylinder pressure of 80.8 bar which increased significantly with the increase in hydrogen rate.     

Parametric studies for improving the performance of a Jatropha oil-fuelled compression ignition engine

A single cylinder, constant speed, direct injection diesel engine was operated on neat Jatropha oil. Injection timing, injector opening pressure, injection rate and air swirl level were changed to study their influence on performance, emissions and combustion. Results have been compared with neat diesel operation. The injection timing was varied by changing the position of the fuel injection pump with respect to the cam and injection rate was varied by changing the diameter of the plunger of the fuel injection pump. A properly oriented masked inlet valve was employed to enhance the air swirl level. Advancing the injection timing from the base diesel value and increasing the injector opening pressure increase the brake thermal efficiency and reduce HC and smoke emissions significantly. Enhancing the swirl has only a small effect on emissions. The ignition delay with Jatropha oil is always higher than that of diesel under similar conditions. Improved premixed heat release rates were observed with Jatropha oil when the injector opening pressure is enhanced. When the injection timing is retarded with enhanced injection rate, a significant improvement in performance and emissions was noticed. In this case emissions with Jatropha oil are even lower than diesel. At full output, the HC emission level is 532 ppm with Jatropha oil as against 798 ppm with diesel. NO level and smoke with Jatropha oil are, respectively 1162.5 ppm and 2 BSU while they are 1760 ppm and 2.7 BSU with diesel.     

Investigation on combustion and emission characteristics of hydrogen-enriched dual-fuel engine operated under waste frying oil biodiesel

Using nonedible waste frying oil (WFO) as biodiesel and hydrogen in the mix composition may partly replace significant quantities of diesel fuel and help reduce fossil fuel reliance. The combination of diesel fuel, waste-fired biodiesel, and hydrogen gas can improve the performance, combustion, and emissions of single-fuel and dual-fuel diesel engines. This may lead to a novel alternative fuel mix pattern and modification for diesel engines, which is the research gap. Although there has been some research on waste-fired biodiesel and hydrogen gas-powered dual-fuel engines with the goal of partly replacing fossil fuels to a larger degree, there has been very little progress in this area. As a result, the current research effort focuses on using diesel fuel (100%, 30%, and 60%), waste-fired biodiesel (at 100%, 70%, and 40%), and hydrogen gas as fuel sources (5 and 10 liters per minute [LPM]). According to the current experiment, it was perceived in both dual-fuel and single-fuel modes. Under duel-fuel mode, the engine results for WFOB70D30 + H10 fuel blend had higher 4.2% (brake thermal efficiency [BTE]), 19.72% (oxides of nitrogen [NO_x]), and 9.09% (ignition delay [ID]) with a minimal range of (in-cylinder pressure, MFB, volumetric efficiency and heat release rate [HRR]) and a dropped rate of 4.34% (brake-specific energy consumption [BSEC]), 33.33% (carbon monoxide [CO]), 39.28% (hydrocarbons [HC]), 9.43% (smoke), and 6.97% (combustion duration [CD]) related to diesel fuel at peak load. However, single-fuel powered diesel engines provide minimal performance for the WFOB40D60 fuel blend with (11.32% lower BTE and 2.04% higher BSEC) and minimal rate of combustion (lower cylinder pressure, 2.12% minimal CD, 14.72% higher ID, minimal HRR combustion, volumetric efficiency, and MFB). Emitted fewer emissions (9.09% less CO, 4.87% less HC, 0.92% higher NO_x, and 1.69% more smoke) than diesel fuel at peak load. Therefore, it was concluded that adding 10 LPM of hydrogen gas to the biodiesel under a dual-fuel condition leads to better combustion, better performance, and less pollution than the single-fuel mode of operation.     

Performance of a stationary diesel engine using vapourized ethanol as supplementary fuel

The modification and testing of a compression ignition engine using diesel and vapourized ethanol as fuel has been carried out. Tests on the engine fuelled with diesel only were made, and the performance evaluated to form a basis for comparison for those of ethanol–diesel dual fuelling.

Modifications were made in the introduction of the ethanol and air. A carburettor was used to vapourize aqueous ethanol into the engine. The effect of preheating the intake ethanol–air mixture was also investigated. Performance was evaluated in terms of engine horsepower, brake specific fuel consumption, brake thermal efficiency, the exhaust gas temperature, lubricating oil temperature and exhaust emissions. The vapourized ethanol partially reduced diesel fuel consumption but also increased total fuel delivery. Vapourization increased power output, thermal efficiency and exhaust emissions but lowered exhaust temperature and lubricating oil temperatures.     

Influence of injection timing on performance,combustion and emission characteristics of Jatropha biodiesel engine

The study of effect of injection timing along with engine operating parameters in Jatropha biodiesel engine is important as they significantly affect its performance and emissions. The present paper focuses on the experimental investigation of the influence of injection timing, load torque and engine speed on the performance, combustion and emission characteristics of Jatropha biodiesel engine. For this purpose, the experiments were conducted using full factorial design consisting of (3³) with 27 runs for each fuel, diesel and Jatropha biodiesel. The effect of variation of above three parameters on brake specific fuel consumption (BSFC), brake thermal efficiency (BTE), peak cylinder pressure (P_max), maximum heat release rate (HRR_max), CO, HC, NO emissions and smoke density were investigated. It has been observed that advance in injection timing from factory settings caused reduction in BSFC, CO, HC and smoke levels and increase in BTE, P_max, HRR_max and NO emission with Jatropha biodiesel operation. However, retarded injection timing caused effects in the other way. At 15 N m load torque, 1800 rpm engine speed and 340 crank angle degree (CAD) injection timing, the percentage reduction in BSFC, CO, HC and smoke levels were 5.1%, 2.5%, 1.2% and 1.5% respectively. Similarly the percentage increase in BTE, P_max, HRR_max and NO emission at this injection timing, load and speed were 5.3%, 1.8%, 26% and 20% respectively. The best injection timing for Jatropha biodiesel operation with minimum BSFC, CO, HC and smoke and with maximum BTE, P_max, HRR_max is found to be 340 CAD. Nevertheless, minimum NO emission yielded an optimum injection timing of 350 CAD.     

Effect of pilot fuel injection pressure and injection timing on combustion,performance and emission of hydrogen-biodiesel dual fuel engine

The present study highlights the influence of fuel injection pressure (FIP) and fuel injection timing (FIT) of Jatropha biodiesel as pilot fuel on the performance, combustion and emission of a hydrogen dual fuel engine. The hydrogen flow rates used in this study are 5lit/min, 7lit/min, and 9lit/min. The pilot fuel is injected at three FIPs (500, 1000, and 1500 bar) and at three FITs (5°, 11°, and 17?bTDC). The results showed an increase in brake thermal efficiency (B_th)from 25.02% for base diesel operation to 32.15% for hydrogen-biodiesel dual fuel operation with 9lit/min flow rate at a FIP of 1500 bar and a FITof17?bTDC. The cylinder pressure and heat release rate (HRR) are also found to be higher for higher FIPs. Advancement in FIT is found to promote superior HRR for hydrogen dual fuel operations. The unburned hydrocarbon (UHC) and soot emissions are found to reduce by 59.52% and 46.15%, respectively, for hydrogen dual fuel operation with 9lit/min flow rate at a FIP of 1500 bar and a FIT of 11?bTDC. However, it is also observed that the oxides of nitrogen (NO_X) emissions are increased by 20.61% with 9lit/min hydrogen flow rate at a FIP of 1500 bar and a FIT of 17?bTDC. Thus, this study has shown the potential of higher FIP and FIT in improving the performance, combustion and emission of a hydrogen dual fuel engine with Jatropha biodiesel as pilot fuel.     

Effect of methanol fumigation on performance and emission characteristics in a waste cooking oil-fuelled single cylinder CI engine

Use of bio-oils in diesel engines results in increased NOx and smoke and reduced brake thermal efficiency. Dual-fuel engines can use a wide range of fuels mainly alcohols and yet operate with high thermal efficiency and simultaneous reduction of NO and smoke emissions. The present study aims to explore the effect of methanol–waste cooking oil (WCO) dual-fuel mode on performance and emission characteristics in a single cylinder Compression ignition (CI) engine producing 3.7 kW at 1,500 rpm. WCO was injected in the conventional injection system, replacing diesel as pilot fuel. Methanol was fumigated along with intake air using a variable jet carburetor, which was installed in the inlet manifold. The methanol was fumigated, and the energy share was varied for each load till the knock limit. Performance parameters like brake thermal efficiency (BTE) and emission parameters like HC, CO, NO, and smoke emissions were tested for various energy shares of methanol with WCO as a pilot fuel. The results show that an increase in methanol fumigation reduced BTE at lower loads. At 75% and 100% load conditions, BTE was higher with methanol addition. The maximum BTE was observed for 38% methanol share, which is about 11% higher, compared to WCO at 100% load condition. Methanol fumigation aided in the simultaneous reduction of NO and smoke emission, and the maximum reduction was occurred with 51% methanol share at 100% load condition. HC and CO emissions were higher at all load conditions with methanol fumigation.     

Performance and exhaust emission characteristics of a CI engine fueled with Pongamia pinnata methyl ester (PPME) and its blends with diesel

Transport vehicles greatly pollute the environment through emissions such as CO, CO₂, NO_x, SO_x, unburnt or partially burnt HC and particulate emissions. Fossil fuels are the chief contributors to urban air pollution and major source of green house gases (GHGs) and considered to be the prime cause behind the global climate change. Biofuels are renewable, can supplement fossil fuels, reduce GHGs and mitigate their adverse effects on the climate resulting from global warming. This paper presents the results of performance and emission analyses carried out in an unmodified diesel engine fueled with Pongamia pinnata methyl ester (PPME) and its blends with diesel. Engine tests have been conducted to get the comparative measures of brake specific fuel consumption (BSFC), brake specific energy consumption (BSEC) and emissions such as CO, CO₂, HC, NO_x to evaluate the behaviour of PPME and diesel in varying proportions. The results reveal that blends of PPME with diesel up to 40% by volume (B40) provide better engine performance (BSFC and BSEC) and improved emission characteristics.