Comparative assessment of a biogas run dual fuel diesel engine with rice bran oil methyl ester,pongamia oil methyl ester and palm oil methyl ester as pilot fuels

The present study tries to explore the potential of three different types of biodiesel viz. Rice bran oil methyl ester (RBME), Pongamia oil methyl ester (PME) and Palm oil methyl ester (POME) as pilot fuels for a biogas run dual fuel diesel engine designed for power generation. The results indicated that under dual fuel mode, RBME-biogas produced a maximum brake thermal efficiency of 19.97% in comparison to 18.4% and 17.4% respectively for PME-biogas and POME-biogas at 100% load. The emission study divulged that under dual fuel mode, on an average, there was an increase of CO emission by 25.74% and 32.58% for PME-biogas and POME-biogas, respectively in comparison to RBME-biogas. Furthermore, on an average, the HC emissions for PME-biogas and POME-biogas increased by 11.73% and 16.27%, respectively in comparison to RBME-biogas. On the other hand, on an average, there was a decrease in NO_X emission by 5.8% and 14%, respectively for PME-biogas and POME-biogas respectively in comparison to RBME-biogas.     

Effect on performance and emissions of a dual fuel diesel engine using hydrogen and producer gas as secondary fuels

Energy is an essential prerequisite for economical and social growth of any country. Skyrocketing of petroleum fuel cost s in present day has led to growing interest in alternative fuels like CNG, LPG, Producer gas, Biogas in order to provide suitable substitute to diesel for a compression ignition engine. This paper discusses some experimental investigations on dual fuel operation of a 4 cylinder (turbocharged and intercooled) 62.5 kW gen-set diesel engine with hydrogen, producer gas (PG) and mixture of producer gas and hydrogen as secondary fuels. Results on brake thermal efficiency and emissions, namely, un-burnt hydrocarbon (HC), carbon monoxide (CO), and NO_x are presented here. The paper also contains vital information relating to the performances of an engine at a wide range of load conditions with different gaseous fuel substitutions. When only hydrogen is used as secondary fuel, maximum increase in the brake thermal efficiency is 7% which is obtained with 20% of secondary fuel. When only producer gas is used as secondary fuel, maximum decrease in the brake thermal efficiency of 8% is obtained with 30% of secondary fuel. Compared to the neat diesel operation, proportion of un-burnt HC and CO increases, while, emission of NO_x reduces in all Cases. On the other hand, when 40% of mixture of producer gas and hydrogen is used (in the ratio (60:40) as secondary fuel, brake thermal efficiency reduces marginally by 3%. Further, shortcoming of low efficiency at lower load condition in a dual fuel operation is removed when a mixture of hydrogen and producer gas is used as the secondary fuel at higher than 13% load condition. Based on the performance studied, a mixture of producer gas and hydrogen in the proportion of 60:40 may be used as a supplementary fuel for diesel conservation.     

Experimental investigation of timed manifold injection of acetylene in direct injection diesel engine in dual fuel mode

The increase in demand and decrease in availability of fossil fuels with more stringent emission norms have led to research in finding an alternative fuel for internal combustion (IC) engines. Among the alternative fuels, gaseous fuels find a great potential. The gaseous fuel taken up for the present study is acetylene, which possesses excellent combustion properties. Preignition is the major problem with this fuel. In the present study, timed manifold injection technique is adopted to induct the fuel into the IC engine. A four-stroke, 4.4 kW diesel engine is selected, with slight modification in intake manifold for holding the gas injector, which is controlled by an electronic control unit (ECU). By using an ECU, an optimized injection timing of 10° after top dead center and 90° crank angle duration are arrived. At this condition, experiments were conducted for the various gas flow rates of 110 g/s, 180 g/s and 240 g/s. The performance was nearer to diesel at full load. Oxides of nitrogen, hydrocarbon and carbon monoxide emission decreased due to lean operation with marginal increase in smoke emission. To conclude, a safe operation of acetylene replacement up to 24% was possible with reduction in emission parameters.     

Effect of manifold and port injection of hydrogen and exhaust gas recirculation (EGR) in dairy scum biodiesel - low energy content gas-fueled CI engine operated on dual fuel mode

In this current work, exhaustive research work is conducted in three phases, in the initial phase, WFO was used for producing WFO treated biomass and in the second phase, influence of PFIP and PFIT has been examined. Further in the successive phase, effect of hydrogen HMI, HPI and EGR on the combustion and emission characteristics of CRDI diesel engine operated on dual-fuel mode using DiSOME and PG combination is evaluated. In the current study, in a CRDI engine, PFIT was employed ranging from 0 to 15°CA bTDC and changed in steps of 5 and PFIP was used from 600 to 1000 bar and varied in successive steps of 200 bar. Further flow rate of hydrogen was kept 8 L/min constant and HMIT was employed in the range from TDC to 15°aTDC and changed in stages of 5. Correspondingly, HID was varied from 30 to 90°CA with 30°CA dwell and EGR was used in the range from 0 to 15% by vol. and varied in steps of 5. Outcome of the work showed that, DiSOME-PG operation with 10°bTDC PFIT, 800 bar PFIP, 10°aTDC of HMI, 60°CAHID and 5% EGR rate showed lower BTE by 5.8% and increased smoke levels by 10.8%, HC by 8.6%, CO by 6.5% and marginally decreased NOx by 6.4% was observed in comparison to the same fuel blend with zero EGR at 80% load. Further, marginally amplifiedID and CD with loweredCP and HRR has been noticed. Study revealed thatH₂addition to low calorific value gas (PG), method of pilot fuel addition and EGR is affected dual fuel engine performance, but provided drastic reductions in smoke and NOx emissions.     

An experimental investigation on engine performance and emissions of a single cylinder diesel engine using hydrogen as inducted fuel and diesel as injected fuel with exhaust gas recirculation

Fast depletion of fossil fuels is demanding an urgent need to carry out research work to find out the viable alternative fuels for meeting sustainable energy demand with minimum environmental impact. In the future, our energy systems will need to be renewable and sustainable, efficient and cost-effective, convenient and safe. The technology for producing hydrogen from a variety of resources, including renewable, is evolving and that will make hydrogen energy system as cost-effective. Hydrogen safety concerns are not the cause for fear but they simply are different than those we are accustomed to with gasoline, diesel and other fossil fuels. For the time being full substitution of diesel with hydrogen is not convenient but use of hydrogen in a diesel engine in dual fuel mode is possible. So Hydrogen has been proposed as the perfect fuel for this future energy system. The experiment is conducted using diesel–hydrogen blend. A timed manifold induction system which is electronically controlled has been developed to deliver hydrogen on to the intake manifold. The solenoid valve is activated by the new technique of taking signal from the rocker arm of the engine instead of cam actuation mechanism. In the present investigation hydrogen-enriched air has been used in a diesel engine with hydrogen flow rate at 0.15 kg/h. As diesel is substituted and hydrogen is inducted, the NO_x emission is increased. In order to reduce NO_x emission an EGR system has been developed. In the EGR system a lightweight EGR cooler has been used instead of bulky heat exchanger. In this experiment performance parameters such as brake thermal efficiency, volumetric efficiency, BSEC are determined and emissions such as oxides of nitrogen, carbon dioxide, carbon monoxide, hydrocarbon, smoke and exhaust gas temperature are measured. Dual fuel operation with hydrogen induction coupled with exhaust gas recirculation results in lowered emission level and improved performance level compared to the case of neat diesel operation.     

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.     

Comparative performance studies of a 4-stroke CI engine operated on dual fuel mode with producer gas and Honge oil and its methyl ester (HOME) with and without carburetor

In order to meet the energy requirements, there has been growing interest in alternative fuels like biodiesels, methyl alcohol, ethyl alcohol, biogas, hydrogen and producer gas to provide a suitable diesel oil substitute for internal combustion engines. Biomass is basically composed of carbon, hydrogen and oxygen. A proximate analysis of biomass indicates the volatile matter to be between 60–80% and 20–25% carbon and the rest, ash. The first part of sub-stoichiometric oxidation leads to the loss of volatiles from biomass and is exothermic; it results in peak temperatures of 1400–1500 K and generation of gaseous products like carbon monoxide, hydrogen in some proportions and carbon dioxide and water vapor, which in turn are reduced in part to carbon monoxide and hydrogen by the hot bed of charcoal generated during the process of gasification. Therefore, solid biomass can be converted into a mixture of combustible gases, and subsequently utilized for combustion in a CI engine. Producer gas, if used in dual fuel mode, is an excellent substitute for reducing the amount of diesel consumed by the CI engine. Downdraft moving bed gasifiers coupled with an IC engine are a good choice for moderate quantities of available biomass, up to 500 kW of electric power. Vegetable oils present a very promising alternative to diesel oil since they are renewable and have similar properties. Vegetable oils offer almost the same power output with slightly lower thermal efficiency when used in diesel engines [1], [2], [3], [4], [5], [6], [7]. Research in this direction with edible oils have yielded encouraging results, but their use as fuel for diesel engines has limited applications due to higher domestic requirement [8], [9], [10]. In view of this, Honge oil (Pongamia Pinnata Linn) is selected and its viscosity is reduced by the transesterification process to obtain Honge oil methyl ester (HOME). Since vegetable oils produce higher smoke emissions, dual fuel operation could be adopted in order to improve their performance. A gas carburetor was suitably designed to maximize the engine performance in dual fuel mode with Honge oil–producer gas and HOME–producer gas respectively. Thus bio-derived gas and vegetable oil, when used in a dual fuel mode with carburetor, resulted in better performance with reduced emissions.     

Experimental study of engine performance and emissions for hydrogen diesel dual fuel engine with exhaust gas recirculation

With an alarming enlargement in vehicular density, there is a threat to the environment due to toxic emissions and depleting fossil fuel reserves across the globe. This has led to the perpetual exploration of clean energy resources to establish sustainable transportation. Researchers are continuously looking for the fuels with clean emission without compromising much on vehicular performance characteristics which has already been set by efficient diesel engines. Hydrogen seems to be a promising alternative fuel for its clean combustion, recyclability and enhanced engine performance. However, problems like high NOx emissions is seen as an exclusive threat to hydrogen fuelled engines. Exhaust gas recirculation (EGR), on the other hand, is known to overcome the aforementioned problem. Therefore, this study is conducted to study the combined effect of hydrogen addition and EGR on the dual fuelled compression ignition engine on a single cylinder diesel engine modified to incorporate manifold hydrogen injection and controlled EGR. The experiments are conducted for 25%, 50%, 75% and 100% loads with the hydrogen energy share (HES) of 0%, 10% and 30%. The EGR rate is controlled between 0%, 5% and 10%. With no substantial decrement in engine's brake thermal efficiency, high gains in terms of emissions are observed due to synergy between hydrogen addition and EGR. The cumulative reduction of 38.4%, 27.4%, 33.4%, 32.3% and 20% with 30% HES and 10% EGR is observed for NOx, CO2, CO, THC and PM, respectively. Hence, the combination of hydrogen addition and EGR is observed to be advantageous for overall emission reduction.     

Engine's behaviour on magnetite nanoparticles as additive and hydrogen addition of chicken fat methyl ester fuelled DICI engine: A dual fuel approach

The present work evaluated the influence of magnetite nanoparticles in chicken fat methyl-ester blend (CFME20) and hydrogen induction in CFME20 nano-fuels combustion performance and exhaust emissions using a 1-cylinder dual DICI engine. Results revealed that CFME20 blend exhibits a significant reduction in smoke, hydrocarbon, and carbon-monoxide emissions; however, increment in oxides of nitrogen and insignificant reduction in BTE also noted. Magnetite nanoparticles mixed with CFME20 through ultrasonication to make nano-additive fuel which noticeably decreased the exhaust emissions including oxides of nitrogen and slightly enhanced the BTE as well. Performance parameters gradually enhanced with escalating nanoparticles dosage up to 100 ppm. Hydrogen induction during nano-additive pilot fuel combustion further decreased the smoke, carbon-monoxide, and hydrocarbon emissions and enhanced the BTE to an appreciable level. However, oxides of nitrogen also enhanced with increasing hydrogen flow rate, but for 10 lpm trivial increased. Hence, the results confirmed that nano-fuel (100 ppm) with hydrogen (10 lpm) addition provides optimum outcomes.     

Influence of hydrogen injection timing and duration on the combustion and emission characteristics of a diesel engine operating on dual fuel mode using biodiesel of dairy scum oil and producer gas

The main aim of the present work is to investigate the influence of hydrogen injection timing and injection duration on the combustion and emissions of a CI engine functioning on dual fuel (DF) mode by employing diesel/dairy scum oil methyl ester (DiSOME)/Waste frying oil methyl ester (WFOME) - producer gas (PG) combination. Hydrogen flow rate was maintained constant (8 lpm) and injected in air-producer gas (PG) mixture an inlet manifold using a gas injector. In this current work, injection timing was varied from TDC to 15 deg., aTDC in steps of 5. Similarly, injection duration was adopted from 30 deg., CA to 90 deg., CA and differed in steps of 30. From the outcome of work, it is noticed that the best possible injection timing and injection duration were found to be 10 deg., aTDC and 60 deg., CA respectively. Results showed that, at optimum injection parameters, diesel-PG combination with hydrogen resulted in augmented BTE by 6.7% and 12.4%, decreased smoke by 26.04% and 36.4%, decreased HC by 16.6% and 22.4%, decreased CO by 23.5% and 29.6% and increased NOx by 12.4% and 22.1%, compared to DiSOME and WFOME supported DF operation. Investigation with DiSOME-hydrogen enriched PG combustion showed satisfactory operation.     

Theoretical and experimental investigations on the performance of dual fuel diesel engine with hydrogen and LPG as secondary fuels

The mathematical models to predict pressure, net heat release rate, mean gas temperature, and brake thermal efficiency for dual fuel diesel engine operated on hydrogen, LPG and mixture of LPG and hydrogen as secondary fuels are developed. In these models emphasis have been given on spray mixing characteristics, flame propagation, equilibrium combustion products and in-cylinder processes, which were computed using empirical equations and compared with experimental results. This combustion model predicts results which are in close agreement with the results of experiments conducted on a multi cylinder turbocharged, intercooled gen-set diesel engine. The predictions are also in close agreement with the results on single cylinder diesel engine obtained by other researchers. A reasonable agreement between the predicted and experimental results reveals that the presented model gives quantitatively and qualitatively realistic prediction of in-cylinder processes and engine performances during combustion.     

Emission analysis of different blends of karanja oil with producer gas in a twin-cylinder diesel engine in dual fuel mode

The present study describes the emission analysis of different blends of karanja oil and diesel with producer gas in dual fuel mode using a twin-cylinder diesel engine in two cases of operations. In case 1, the above fuels are tested in single mode and in dual fuel mode operation at an optimum gas flow rate of 21.49 Kg/h under different load conditions. Similarly, in case 2 the same test fuels are used in dual fuel mode only at an optimum load of 10 kW under different gas flow rates. The study reveals that dual fuel operation of all test fuels shows lower smoke and oxide of nitrogen emissions compared to their single mode operation, whereas other emission parameters are on the higher side. However, all blended fuels show better emissions compared to diesel in both cases of operations.     

Hydrogen supplemented natural gas effect on a DI diesel engine operating under dual fuel mode with a biodiesel pilot fuel

In order to slow down the continuing environmental deterioration, regulations for pollutant emissions limitations are increasingly rigorous. The development of new alternative fuels for internal combustion engines is a very interesting solution not only to overcome the pollution problem but also because of the petroleum shortage. In this context, the present work investigates the improvement of a DI diesel engine operating at constant speed (1500 rpm) and under dual fuel mode with eucalyptus biodiesel and natural gas (NG) enriched by various H₂ quantities (15, 25 and 30 by v%). The eucalyptus biodiesel quantity injected into the engine cylinder is kept constant, to supply around 10% of the engine nominal power, for all examined engine loads. The engine load is further increased using only the gaseous fuel (NG+H₂), which is introduced with the intake air. The effect of H₂/NG blending ratio on the combustion parameters, performance and pollutant emissions of the engine is investigated and compared with those of pure NG case. An important benefit in terms of brake specific fuel consumption, reaching a decrease of 4–10% with the 25% H₂ blend compared to the pure NG case, is achieved. Concerning the pollutant emissions, NG enrichment with H₂ is an efficient solution to enhance the combustion process and hence reduce carbon monoxide, unburned hydrocarbon and soot emissions at high loads where they are important for pure NG. However for the nitrogen oxide emissions, NG blending with H₂ is attractive only at low and medium loads where their levels are lower than pure NG.     

Optimum ratio of compressed biomethane gas as dual fuel in turbocharged common rail diesel engine

During the world faced a crude oil price crisis, the selling price of all fuel types increased considerably. Commercial carriers that use vehicles installed with the turbocharged common rail diesel engine (TCRD Engine) attempted to find methods to reduce the fuel cost. One of the many alternative methods was the use of compressed biomethane gas (CBG) together with diesel, which was called as the dual fuel. In general, the amount of CBG supplied into the engine is mostly adjusted to be in the highest ratio without taking care of the influences on the engine and the environment. In order to introduce a guideline to adjust the CBG dual fuel correctly, this study has been conducted with objectives as follows: (i) to study the optimum ratio of CBG on unmodified TCRD engine, (ii) to describe the effect of critical factors on the optimum duration of CBG injection, and (iii) to analyze the fuel cost and the economical break-even point. The test was conducted on a 2.5L, four-cylinder, four-stroke, TCRD Engine in which the crankshaft end was coupled to the hydraulic dynamometer for measuring and controlling the torque to be constant as the reference torques obtained from the use of the pure diesel. The study found that the trend of variation in the optimum ratio of CBG significantly depended on the trend of the optimum duration of CBG injection, that is, increasing in low engine speed ranges, being constant at relatively high values during medium to high engine speeds, and, finally, decreasing to reach the lowest at the highest engine speed that the CBG can be supplied safely. The critical factors to define the optimum ratio of CBG consisted of smoke opacity in exhaust gas, exhaust gas temperature, and engine knock, which dominated differently for each of the different values of engine speed and torque. The analysis on fuel consumption and fuel cost showed that although the brake specific fuel consumption (BSFC) of the CBG and diesel dual fuel was higher than that of diesel, the fuel cost of the dual fuel was less than that of diesel because of the lower price of the CBG. This study also presented that CBG could be safely used as a dual fuel in unmodified TCRD engines if suitable critical factors to limit the optimum ratio of CBG were defined. Moreover, CBG was confirmed as suitable for use as the dual fuel with diesel without modification of the engine except the installation on the gas supply system. Therefore, these results can be followed to promote a decrease in the overall cost in the use of the TCRD engine in commercial transportation with high effectiveness and safety to the engine and the environment.     

The effect of biodiesel fuel obtained from waste frying oil on direct injection diesel engine performance and exhaust emissions

In this study, usage of methyl ester obtained from waste frying oil (WFO) is examined as an experimental material. A reactor was designed and installed for production of methyl ester from this kind of oil. Physical and chemical properties of methyl ester were determined in the laboratory. The methyl ester was tested in a diesel engine with turbocharged, four cylinders and direct injection. Gathered results were compared with No. 2 diesel fuel. Engine tests results obtained with the aim of comparison from the measures of torque, power; specific fuel consumptions are nearly the same. In addition, amount of emission such as CO, CO₂, NO_x, and smoke darkness of waste frying oils are less than No. 2 diesel fuel.     

Emission analysis of different blends of karanja biodiesel with producer gas in a twin cylinder diesel engine in dual fuel mode

The present study demonstrates the emission analysis of different blends of Karanja biodiesel and diesel with producer gas in dual fuel mode using a twin cylinder diesel engine for two cases of operations. In case 1, a test is carried out using the above test fuels both in single mode and dual fuel mode operation with a constant gas flow rate of 21.49 Kg/h under different load conditions. Similarly, in case 2, a test is performed at a constant load of 10 kW under different gas flow rates using the same test fuels in the dual fuel mode only. The study reveals that all blended fuels show better emissions compared to diesel in both cases of operations. Dual fuel mode operation of all tested fuels shows lower smoke and oxide of nitrogen emissions compared to their single mode operation under all load conditions, whereas other emission parameters are found to be on the higher side.     

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.     

Effect of manifold injection of hydrogen gas in producer gas and neem biodiesel fueled CRDI dual fuel engine

The high flammability of hydrogen gas gives it a steady flow without throttling in engines while operating. Such engines also include different induction/injection methods. Hydrogen fuels are encouraging fuel for applications of diesel engines in dual fuel mode operation. Engines operating with dual fuel can replace pilot injection of liquid fuel with gaseous fuels, significantly being eco-friendly. Lower particulate matter (PM) and nitrogen oxides (NO_x) emissions are the significant advantages of operating with dual fuel.Consequently, fuels used in the present work are renewable and can generate power for different applications. Hydrogen being gaseous fuel acts as an alternative and shows fascinating use along with diesel to operate the engines with lower emissions. Such engines can also be operated either by injection or induction on compression of gaseous fuels for combustion by initiating with the pilot amount of biodiesel. Present work highlights the experimental investigation conducted on dual fuel mode operation of diesel engine using Neem Oil Methyl Ester (NeOME) and producer gas with enriched hydrogen gas combination. Experiments were performed at four different manifold hydrogen gas injection timings of TDC, 5°aTDC, 10°aTDC and 15°aTDC and three injection durations of 30°CA, 60°CA, and 90°CA. Compared to baseline operation, improvement in engine performance was evaluated in combustion and its emission characteristics. Current experimental investigations revealed that the 10°aTDC hydrogen manifold injection with 60°CA injection duration showed better performance. The BTE of diesel + PG and NeOME + PG operation was found to be 28% and 23%, respectively, and the emissions level were reduced to 25.4%, 14.6%, 54.6%, and 26.8% for CO, HC, smoke, and NO_x, respectively.