Effect of changing injection pressure on Mahua oil and biodiesel combustion with CeO2 nanoparticle blend on CI engine performance and emission characteristics

Alternative fuels have sparked a lot of interest as oil deposits have decreased and environmental concerns have grown. Biodiesel is an alternative fuel that is being researched as a possible replacement for fossil fuels. In the current investigation, the combustion performance, and emission characteristics of CI(Compression Ignition) engine were examined by changing the fuel injection pressure (180, 200, 220 and 240 bar). The biodiesel (B20) used in this analysis was obtained from Mahua oil at 20% v/v blended with neat diesel (20% Mahua Biodiesel + 80% Diesel). CeO₂(Cerium Oxide) nanoparticles were introduced to the B20 fuel at four distinct concentrations are 25, 50, 75, and 100 ppm. Performance characteristics such as BTE(Brake Thermal Efficiency) and BSFC(Brake Specific Fuel Consumption) were inferior to diesel, at 240 bar B20 with 25 ppm CeO₂ indicated 1.9% increased BTE and 3.8% reduced BSFC compared B20 and 6% lower EGT (Exhaust Gas Temperature) compared diesel. At 200 bar, fuel samples indicated slightly higher In-Cylinder pressure and lower HRR (Heat release rate) compared to diesel. At 200 bar FIP(Fuel Injection Pressure), HC(Hydro Carbon) and CO(Carbon Monoxide) emissions were reduced significantly compared to diesel. The largest reduction in smoke opacity and NOx(Nitrous Oxide) emissions were observed at 240 bar with 75 ppm dosage, but CO₂(Carbon Dioxide) emissions were higher at 220 bar.     

Performance and emission study of preheated Jatropha oil on medium capacity diesel engine

Diesel engines have proved its utility in transport, agriculture and power sector. Environmental norms and scared fossil fuel have attracted the attention to switch the energy demand to alternative energy source. Oil derived from Jatropha curcas plant has been considered as a sustainable substitute to diesel fuel. However, use of straight vegetable oil has encountered problem due to its high viscosity. The aim of present work is to reduce the viscosity of oil by heating from exhaust gases before fed to the engine, the study of effects of FIT (fuel inlet temperature) on engine performance and emissions using a dual fuel engine test rig with an appropriately designed shell and tube heat exchanger (with exhaust bypass arrangement). Heat exchanger was operated in such a way that it could give desired FIT. Results show that BTE (brake thermal efficiency) of engine was lower and BSEC (brake specific energy consumption) was higher when the engine was fueled with Jatropha oil as compared to diesel fuel. Increase in fuel inlet temperature resulted in increase of BTE and reduction in BSEC. Emissions of NO_x from Jatropha oil during the experimental range were lower than diesel fuel and it increases with increase in FIT. CO (carbon monoxide), HC (hydrocarbon), CO₂ (carbon dioxide) emissions from Jatropha oil were found higher than diesel fuel. However, with increase in FIT, a downward trend was observed. Thus, by using heat exchanger preheated Jatropha oil can be a good substitute fuel for diesel engine in the near future. Optimal fuel inlet temperature was found to be 80 °C considering the BTE, BSEC and gaseous emissions.     

Combustion,performances, and emissions characteristics of Hermetia illucens larvae oil in a direct injection compression ignition engine

Hermetia illucens larvae oil (HILO) is among biofuel feedstock from insects that has high potential to reduce dependency on petroleum resources. The present paper is motivated by the need to critically examine the effect of HILO mixed with diesel fuel (DF) on combustion, engine performance, and emission characteristics of a single cylinder direct injection (DI) compression ignition (CI) engine. The experiment was performed at a constant speed of 1500 rpm under various engine loads. The results revealed that the in-cylinder pressure, heat release rate (HRR), and the ignition delay (ID) were reduced by an average of 3.32%, 12.89%, and 4.36%, respectively. The brake specific fuel consumption (BSFC) and exhaust gas temperature (EGT) increased considerably at all engine loads. The brake thermal efficiency (BTE) was discovered to be lower by 11.47% compared to DF. The finding also shows that carbon monoxide (CO), carbon dioxide (CO₂), and unburned hydrocarbon (UHC) emissions increased with the addition of HILO. The nitrogen oxides (NO_x) emission reduced by 19.80% compared to DF at all the engine loads. Overall, this study concluded the potential of HILO in CI engine as a promising renewable and environmentally friendly resource for the better earth.     

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.     

Synergetic effect OF CI engine characteristics when fuelled with neem oil methyl ester enriched with a oxy-hydrogen gas

The Neem-oil methyl ester (NME) produced from transesterification of Neem-oil was mixed with diesel fuel in the share of 10%(N10) and 20%(N20) were used with varying flow rate of oxy-hydrogen gas (HHO) gas at 5%,10% and 15% energy share along with exhaust gas recirculation (EGR) in a 3.7 kW CI engine. Presence of fuel-borne oxygen in NME, facilitates increase in brake thermal efficiency (BTE) at high load related to neat diesel operation. Further the BTE was improved by introducing varying flow rate of HHO gas in order to maintain energy share of 5, 10 and 15% at all loads. The BTE was found as 33.80% and 35.40% for N20 + 10%HHO and N20 + 15%HHO compared to 31.5%, 30.4% and 29.4% for N20, N10 and Neat diesel fuel respectively. Significant emission reduction of CO, CO₂, uHC and smoke opacity were observed during NME + HHO gas operation, but NOx emission was augmented which was controlled using EGR along with further improvement in the engine characteristics.     

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.     

Biodiesel production from waste cooking oil using heterogeneous catalysts and its operational characteristics on variable compression ratio CI engine

In the present work, the optimum biodiesel conversion from waste cooking oil to biodiesel through transesterification method was investigated. The base catalyzed transesterification under different reactant proportions such as the molar ratio of alcohol to oil and mass ratio of catalyst to oil was studied for optimum production of biodiesel. The optimum condition for base catalyzed transesterification of waste cooking oil was determined to be 12:1 and 5 wt% of zinc doped calcium oxide. The fuel properties of the produced biodiesel such as the calorific value, flash point and density were examined and compared to conventional diesel. The properties of produced biodiesel and their blend for different ratios (B20, B40, B60, B80 and B100) were comparable with properties of diesel oil and ASTM biodiesel standards. Tests have been conducted on CI engine which runs at a constant speed of 1500 rpm, injection pressure of 200 bar, compression ratio 15:1 and 17.5, and varying engine load. The performance parameters include brake thermal efficiency, brake specific energy consumption and emissions parameters such as Carbon monoxide (CO), Hydrocarbon (HC), Oxides of Nitrogen (NOx) and smoke opacity varying with engine load (BP). Diesel engine's thermal performance and emission parameters such as CO, HC, and NOx on different biodiesel blends demonstrate that biodiesel produced from waste cooking oil using heterogeneous catalyst was suitable to be used as diesel oil blends and had lesser emissions as compared to conventional diesel.     

Effects of turpentine and gasoline-like fuel obtained from waste lubrication oil on engine performance and exhaust emission

In this study, an experimental investigation was carried out to determine the effects of gasoline-like fuel (GLF), and its blends with turpentine with ratios of 10%, 20%, and 30% on the performance and emission characteristics of a gasoline engine. The GLF was obtained from waste lubrication engine oil by the method of pyrolitic distillation. Characteristics of the pure GLF and its blends were tested. A series of engine performance and emission tests were conducted using the fuel samples in the test engine. Performance parameters for each test were calculated utilizing measurement values of force exerted on the crank shaft, rate of air and fuel mass flow to the engine and engine speed. Effects of the fuels on the performance parameters, exhaust gas temperature, and emissions of NOx, CO, CO₂, and HC were discussed. The results indicated that torque, brake mean effective pressure and thermal efficiency increased but brake specific fuel consumption decreased with increasing amount of turpentine in the GLF sample. The main effect of 10%, 20% and 30% turpentine additions to GLF on pollutant formation was that the NOx ratio increased, whereas that of CO decreased.     

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.     

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.     

Energy,exergy and emission analysis on a DI single cylinder diesel engine using pyrolytic waste plastic oil diesel blend

Depletion of fossil fuels and stringent emission norms focus attention to discover an evitable source of alternative fuel in order to attribute a significant compensation on conventional fuels. Besides, waste management policies encourage the valorization of different wastes for the production of alternative fuels in order to reduce the challenges of waste management. In this context, pyrolysis has become an emerging trend to convert different wastes into alternate fuel and suitable to be used as a substitute fuel for CI engines. The current investigation provides a sustainable and feasible solution for waste plastic management by widening the gap between global plastic production and plastic waste generation. It investigates the performance and emission of a single cylinder DI four stroke diesel engine using waste plastic oil (WPO) derived from pyrolysis of waste plastics using Zeolite-A as catalyst. Engine load tests have been conducted taking waste plastic oil and subsequently a blend of waste plastic oil by 10%, 20%, and 30% in volume proportions with diesel as fuel. The performance of the test engine in terms of brake thermal efficiency is found marginally higher and brake specific fuel consumption comparatively lowest for 20% WPO-diesel blend than pure diesel. The NOx and HC emission is found lower under low load condition and became higher by increasing the load as compared to diesel. Fuel exergy was significantly increasing after blending of WPO with pure diesel, but exergetic efficiency of the blended fuels followed the reverse trend. However, increase in load of the engine improved the exergetic efficiency. The 20% WPO–diesel blended fuel is found suitable to be used as an alternative fuel for diesel engine.     

Preparation and characterization of pyrolytic oil through pyrolysis of neem seed and study of performance,combustion and emission characteristics in CI engine

This paper deals with production of pyrolytic oil from neem seed and using this pyrolytic oil in the form of blend with fossil diesel to study the performance and emission characteristics in CI engine. Thermal and catalytic pyrolysis of non edible neem seed was performed in a slow fixed bed pyrolyser to produce pyrolytic oil. Maximum pyrolytic oil obtained in thermal pyrolysis was 55% wt and in catalytic pyrolysis was 60% wt using both Al₂O₃ and K₂CO₃ catalysts followed by 41% wt and 38% wt for zeolite and kaolin catalysts respectively. The catalytic pyrolysis improved pH and calorific values of 12.4% and 14.4% respectively as compared to thermal pyrolysis. Blends of neem seed catalytic pyrolytic oil (NB) with fossil diesel in the ratio of 5% (NB5) and 10% (NB10) by volume were tested on an unmodified CI engine. Brake thermal efficiency (BTE) was lower at part load conditions and higher at full load condition up to 3.7% in the case of blends as compared to fossil diesel operation. Higher Brake Specific Fuel Consumption (BSFC) was observed in the case of NB5 blend on all load conditions, up to 23.9%. Reduction in emission levels were observed for HC (46.9%), CO (42.2%), CO₂ (29.8%) and NOx (20.7%) at full load condition. This study observed that neem seed catalytic pyrolytic oil is a potential renewable and sustainable green fuel.     

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

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

Effect of hydrogen on compression-ignition (CI) engine fueled with vegetable oil/biodiesel from various feedstocks: A review

Compression ignition (CI) engines used in the transportation sector operates on fossil diesel and is one of the biggest causes of air pollution. Numerous studies were carried out over last two decades to substitute the fossil diesel with biofuels so that the net carbon dioxide (CO₂) emission can be minimized. However, the engine performance with these fuel was sub-standard and there were many long-term issues. Therefore, many researchers inducted hydrogen along with the biofuels. The present study gives an outlook on the effect of hydrogen addition with biodiesel/vegetable oil from various sources in CI engine. Engine parameters (brake thermal efficiency, brake specific fuel consumption), combustion parameters (in-cylinder pressure and heat release rate) and emission parameters (unburned hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and smoke emissions) were evaluated in detail. The results show that hydrogen induction in general improves the engine performance as compared to biodiesel/vegetable oil but it is similar/lower than diesel. Except NOx emissions all other emissions showed a decreasing trend with hydrogen addition. To counter this effect numerous after-treatment systems like selective catalytic reduction (SCR), exhaust gas recirculation (EGR), selective non-catalytic reduction system (SNCR) and non-selective catalytic reduction system (NSCR) were proposed by researchers which were also studied in this review.     

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 investigation of the influence of blending on engine emissions of the diesel engine fueled by mahua biodiesel oil

The present article elaborates on the various emission characteristics of mahua oil with diesel fuel in a diesel engine at various blending conditions. Experimental investigation results are studied for various parameters such as exhaust emission of carbon monoxide (CO), hydrocarbon (HC), and oxides of nitrogen (NO) gases and exhaust gas temperature. Results show that residual oxygen, CO, HC, and NO emission were the lowest for mahua biodiesel compared with diesel. The experimental results proved that the use of mahua oil biodiesel as fuel in the diesel engine is a viable alternative to diesel fuel. Mahua biodiesel oil may be beneficial in decreasing greenhouse gas emissions without any engine modification. Mahua oil has the possibility of becoming a sustainable fuel source as biodiesel.     

The effects of turbocharger on the performance and exhaust emissions of a diesel engine fuelled with biodiesel

This paper investigates the effects of turbocharger on the performance of a diesel engine using diesel fuel and biodiesel in terms of brake power, torque, brake specific consumption and thermal efficiency, as well as CO and NO_x emissions. For this aim, a naturally aspirated four-stroke direct injection diesel engine was tested with diesel fuel and neat biodiesel, which is rapeseed oil methyl ester, at full load conditions at the speeds between 1200 and 2400 rpm with intervals of 200 rpm. Then, a turbocharger system was installed on the engine and the tests were repeated for both fuel cases. The evaluation of experimental data showed that the brake thermal efficiency of biodiesel was slightly higher than that of diesel fuel in both naturally aspirated and turbocharged conditions, while biodiesel yielded slightly lower brake power and torque along with higher fuel consumption values. It was also observed that emissions of CO in the operations with biodiesel were lower than those in the operations with diesel fuel, whereas NO_x emission in biodiesel operation was higher. This study reveals that the use of biodiesel improves the performance parameters and decreases CO emissions of the turbocharged engine compared to diesel fuel.     

Combustion characteristics of CI engine fueled with WCO biodiesel/diesel blends at different compression ratios and EGR

The present study investigated the effect of compression ratio (CR) with the use of exhaust gas recirculation (EGR) technology on the performance of combustion characteristics at different CRs and engine loads; the brake thermal efficiency (BTE), specific fuel consumption (SFC), volumetric efficiency (VOL.EFF), exhaust gas temperature, carbon dioxide emission (CO₂), hydrocarbons (HC), nitrogen oxides (NOx), and oxygen content (O₂). The single-cylinder, four-stroke compression ignition engine was run on a mixture of diesel and biodiesel prepared from Iraqi waste cooking oil at (B0, B10, B20, and B30). A comparison has been achieved for these combustion characteristics at different blends, load, and CRs (14.5, 15.5, and 16.5) at 1500 rpm constant engine speed. The transesterification process is used to produce biodiesel and ASTM standards have been used to determine the physical and chemical properties of biodiesel and compare them to net diesel fuel. The preliminary conducting tests indicated that engine performance and emissions improved with the B20 mixture. Experimental test results showed an increase in BTE when CR increased by 17% and SFC increased by 23%. It also found a higher VOL.EFF by 6% at higher pressure ratios. A continuous decrease in BTE values and an increase in SFC were sustained when the percentage of biodiesel in the mixture was increased. Emissions of carbon dioxide, HC, and NOx increased by 12%, 50%, and 40%, respectively, as CR reached high values. NOx increased with the addition of biodiesel to 35%, which necessitated the use of EGR technology at rates of 5% and 10%. The results indicated that the best results were obtained in the case of running the engine with a mixing ratio of B20 with the addition of 10% EGR, NOx decreased by 47% against a slight increase in other emissions.     

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

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

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.