Biodiesel Diesel Research Articles

Characteristics of High-Pressure Injection Pump Operated with Renewable Fuel for Diesel Engines

The use of renewable fuels for internal combustion engines marks a significant stride towards sustainability in transportation and power generation. Ensuring the compatibility of these fuels with existing diesel engines and infrastructure is paramount for a smooth transition. Diesel engines capable of harnessing the advantages of alternative fuels without extensive modifications offer a pragmatic approach to sustainable power for vehicles and industries. This article investigates the impact of carbon-neutral renewable fuel types (hydrogenated vegetable oils, or HVOs, and biodiesel) on the operation of a high-pressure injection pump, focusing on rotational speed and delivery pressure as key parameters. Our investigation, based on pump operating cycle analysis and volumetric efficiency measurements, aimed to investigate to what extent shaft speed and fuel type influence pump performance. Hydrogenated carbon-neutral fluids (HVOs) demonstrate adequate hydraulic capabilities compared to conventional fossil fuels. The findings underscore that while the fluids under consideration vary in viscosity and compressibility modulus, it is the compressibility modulus that predominantly affects the pump’s operation cycle. Diesel (fossil) fluid exhibits intermediate characteristics compared to hydrogenated fossil diesel fluids and biodiesel. The differences in terms of volumetric efficiency are finally reported, showing that hydrogenated carbon-neutral fluids do not significantly hinder the pump’s flow rate transfer capability.

Physicochemical exploration of castor seed oil for high-quality biodiesel production and its sustainable application in agricultural diesel engines

In Thailand, castor seeds often classified as weeds are locally distributed in every region of the country and not fully utilized. Therefore, this research aimed to study the physicochemical properties of castor seed oil as a raw material for the production of liquid biofuels. The study of extracting oil from castor seeds using various methods revealed that the Soxhlet extraction technique, a circulatory extraction method, yielded the highest amount of extracted oil at 52.45 wt%, compared to the dry weight of the castor seed. In the study of the physicochemical properties of castor seed oil, the results revealed that the major components were 89.71% ricinoleic acid, 3.96% linoleic acid, and 3.09% oleic acid, respectively. The kinematic viscosity of castor seed oil was as high as 164.68 cSt. However, when converted into castor seed oil biodiesel, the kinematic viscosity decreased to 10.36 cSt, still two times higher than that of the standard biodiesel oil. Therefore, blending castor seed oil biodiesel with petroleum diesel oil to obtain B30 and B40 revealed that the fuel properties met the qualifications of both ASTM D6751 and EN 14214 standards. The initial tests on agricultural diesel engines found that the gas emissions of CO2, CO, HC, and NO2 from biodiesel blends B30 and B40 tend to be lower than those from using only petroleum diesel oil and biodiesel oil derived from castor seeds. Therefore, blending biodiesel oils B30 and B40, derived from castor seed oil, not only results in good biofuel liquid qualities but also proves to be efficient for use in agricultural diesel engines. It is suitable to encourage the community to adopt it for agricultural purposes in the future.

Experiment investigation on Momordica Charantia biodiesel in CRDI engine with cerium oxide (CeO2) nanoadditives

Most of the transportation fuel is diesel. This type of fuel is widely used and helps the economy by providing high combustion efficiency and affordability. The goal of this study was to analyse the performance and characteristics of a multi-cylinder diesel engine utilising a rail direct injection system and fuel that's composed of 20% momordica. The addition of cerium oxide nanoparticles in the fuel mass fractions of 20 and 40 ppm was performed using an ultrasonicator and a mechanical homogeniser. These small particles help improve fuel stability and prevent injector blockages. By adding cerium oxide nanoparticles to the biodiesel–diesel blend, brake thermal efficiency and heat release rate were also improved. At full load, the MC20 emits 12.341 g/kW h of HC and 84 HSU of smoke, compared to 9.021 g/kW h and 52 HSU for the CONP 40 blended MC20. It is recommended to use cerium oxide nanoparticles at a concentration of 40 ppm for optimal performance, emission combustion, and characteristic enhancement.

Mitigating imported fuel dependency in agricultural production: Case study of an island nation's vulnerability to global catastrophic risks.

A major global catastrophe would likely disrupt trade in liquid fuels. Countries dependent on imported oil products might struggle to sustain industrial agriculture. Island nations importing 100% of refined fuels are particularly vulnerable. Our case study aimed to estimate the agricultural land area and biofuel volumes needed to feed the population of New Zealand in the absence of trade. Results showed that stored diesel would quickly be exhausted with ordinary use (weeks) and even with strict rationing (months). To preserve fuel, we found that farming wheat (requiring as little as 5.4 million liters [L] of diesel per annum) was more fuel-efficient than potatoes (12.3) or dairy (38.7) to feed the national population under a climate-as-usual scenario. In a nuclear winter scenario, with reduced agricultural yields, proportionately greater diesel is needed. The wheat would require 24% of current grain-cropped land, and the canola crop used as feedstock for the required biofuel would occupy a further 1%-7%. Investment in canola biodiesel or renewable diesel refineries could ensure supply for the bare minimum agricultural liquid fuel needs. Were subsequent analysis to favor this option as part of a fuels resilience response and as a tradeoff for routine food use, expansion in refining and canola cropping before a catastrophe could be encouraged through market mechanisms, direct government investment, or a combination of these. Logistics of biofuel refining scale-up, post-catastrophe, should also be analyzed. Further, biodiesel produced in normal times would help the nation meet its emissions reduction targets. Other countries should conduct similar analyses.

Vibration analysis using wavelet transformation technique and performance characteristics of a diesel engine fueled with tamarind biodiesel-diesel blends and diverse additives

This study investigates the combustion, performance characteristics, and emission levels of diesel and tamarind biodiesel mixtures (B20, B30, B40, and B100) in a single-cylinder, four-stroke, direct injection (DI) diesel engine. Further, two fuel additives, namely Butylated Hydroxytoluene (BHT) (an antioxidant) and Diethyl ether (DEE) (a cetane improver), were separately added to B20 to enhance the engine characteristics. In addition, Wavelet Transform and Wavelet Packet algorithms were used to investigate the vibration behaviour of the tested fuels. The results demonstrate that the B20 blend improved the performance and generated less emission than the other blends. Moreover, the brake thermal efficiency (BTE) and brake-specific fuel consumption (BSFC) for B20+BHT were 3.8% higher and 4.1% less than B20, respectively. B20+DEE combustion showed lower CO and smoke pollutants by 51% and 19% compared to B20, respectively. The NOx emissions for the blends containing BHT and DEE were decreased by 16% and 9%, respectively. The engine vibration analysis showed almost the same frequency with fuel blends B20 and B30, which were similar to the diesel fuel values. The results concluded the tamarind biodiesel/diesel mixtures with BHT and DEE improved the performance and emissions behaviors of DI diesel engine and could be considered a potential alternative biofuel for such engines. Wavelet analysis of the engine was accurately employed to extract the prominent features of the vibrations.

Performance and emissions assessment under full load operation of an unmodified diesel engine running on biodiesel-based waste cooking oil synthesized using JPW solid catalyst

The current study builds upon the prior research (Mulkan et al., 2023) [1], which successfully created an innovative solid catalyst from discarded jackfruit peel waste (JPW) to produce biodiesel from waste cooking oil (WCO). Expanding on this initial research, our study's primary objective is to assess the performance and emissions attributes of a diesel engine when utilizing blends of WCO biodiesel and conventional diesel fuel under full load conditions, covering engine speeds from 1200 to 2400 rpm. The results show that as engine speed increases, brake-specific fuel consumption (BSFC) decreases by an average of 16.67%–22.69%, while brake thermal efficiency (BTE) increases by 16.67%. Engine torque initially decreases and drops significantly at higher speeds, while brake power (BP) proportionally rises. Notably, substantial reductions in CO emissions (ranging from 6.11% to 48.63%) were observed at all engine speeds compared to pure diesel. However, CO2 and NO emissions generally increased, although some fuel samples demonstrated reductions. Hydrocarbon emissions decreased with higher engine speeds, while smoke opacity increased, with slight reductions observed for specific fuel samples at 1800–2400 rpm. In conclusion, blending WCO biodiesel synthesized using the JPW catalyst with pure diesel results in improved engine performance and reduced exhaust emissions.

Determining the effect of tung biodiesel on thermodynamic, thermoeconomic, and exergoeconomic analyses at high engine speeds

Tung biodiesel is a promising alternative fuel type produced from the tung tree. In the current study, the effect of the addition of 20%, by volume, of tung biodiesel to diesel fuel was evaluated in terms of energetic–exergetic analyses based on the first and second laws of thermodynamic at various high engine speeds (2,400, 2,600, and 2,800 rpm). Additionally, this study aimed to assess the thermoeconomic and exergoeconomic aspects of a diesel engine. The findings revealed that the amount of energy converted to useful work for the diesel fuel was higher than that of the DTB20 fuel, even though the fuel energy obtained from DTB20 fuel was higher than that of diesel fuel at all engine speeds. The highest energy and exergy efficiencies for the engine fueled with diesel fuel were obtained as 31.07% and 29.15% respectively, while the corresponding values for the engine fueled with DTB20 fuel were determined as 27.15% and 25.19% at the engine speed of 2,400 rpm, respectively. However, at 2,800 rpm, a significant decrease in both the energy and exergy efficiencies was observed for both diesel and tung biodiesel blended fuels due to the increased mechanical friction of the engine components. Furthermore, at the highest engine speed, entropy generation increased, owing to a higher exergy destruction rate. The entropy generation rate increased to 0.38 kW/K for diesel fuel and 0.46 kW/K for DTB20 fuel since the enhancement of the engine speed caused the ascent of the fuel consumption rate. Regarding thermoeconomic–exergoeconomic analyses, for both diesel and tung biodiesel blended fuels, there is no distinct difference in the thermoeconomic–exergoeconomic parameters at 2,400 and 2,600 rpm as the values of these parameters at the engine speed of 2,800 rpm increased significantly. In light of all the findings, it can be concluded that the engine speed of 2,800 rpm is not applicable to run the engine due to higher friction and corresponding energy destruction in the engine system.

Improvement of worsened diesel and waste biodiesel fuelled-engine characteristics with hydrogen enrichment: A deep discussion on combustion, performance, and emission analyses

Due to the strict emission policies, fuel researchers are dedicated to mitigating the tailpipe emissions from internal combustion engines (ICEs). Therefore, researchers have considered biodiesel as the best alternative to conventional diesel fuel (D) for a while. However, many scientific papers experimentally announced that the use of biodiesel significantly worsens engine behaviors. In this framework, hydrogen enrichment has become a very reasonable option in order to minimize the reverse influences of biodiesel-fuelled engine characteristics. In this direction, waste cooking of 25% (B25) was volumetrically blended to D and reference data was collected. Then, 15 and 30 Lpm hydrogen was introduced from the intake manifold by mixing with air along with B25 test fuel to observe the changes from the hydrogen effect. Tests were performed on a three-cylinder, water-cooled diesel engine at constant engine speed (2000 rpm) and variable engine loads (15, 30, 45 and 60 Nm). In the results, it is witnessed that BSFC (brake specific fuel consumption) for B25 fuel increased by 8.23% as compared D fuel. However, along with the introduction of 15 and 30 Lpm hydrogen to B25 fuel, the BSFC value dropped by 17.58%, and 30.75%, respectively. In a similar way, B25 test fuel reduces BTE (brake thermal efficiency) by 7.54% as compared to D fuel. However, the hydrogen introduction of 15 and 30 Lpm (Litre per minute) along with B25 fuel improves the BTE value by 10.19%, and 17%, respectively. On the other hand, the inclusion of 15 Lpm and 30 Lpm H2 to B25 fuel provided a reduction of 23.75% and 45.59% for HC (Hydrocarbon) emissions, and 53.1% and 62.6% for NOx (Nitrogen oxide) emissions, respectively. In conclusion, it is seen that deteriorations in combustion, performance, and emission characteristics resulting from the use of biodiesel can be minimized by using hydrogen for ICEs.

Influence of phenolic antioxidant additives on performance and emission characteristics of diesel engine fuelled with Jatropha biodiesel: A sustainable hybrid model using RSM and ANFIS

This study aimed to assess the inclusion of antioxidant diphenylamine (DPA) to a Jatropha biodiesel (B30) blend to affects engine performance and exhaust emissions. In this research, three fuel blends has been utilized: diesel, B30, and 100 ppm of antioxidant diphenylamine is added to the B30 blend referred to as B30 + DPA100. A Response Surface Methodology (RSM) has been employed to analyze experimental data, resulting in the development of a regression equation. Additionally, an Adaptive Neuro-Fuzzy Inference System (ANFIS) has been employed to assess and verify the consistency of the developed model. The results from the experiments revealed that the inclusion of the antioxidant had a notable impact on reducing NOx emissions with only a slight effect on brake thermal efficiency (BTHE). Specifically, B30 + DPA100 showed a 7.48 and 15.53% decrease in average NOx emissions, while the average BTHE experienced a modest 0.78% decrease and a 2.67% increase compared to diesel and B30 biodiesel blend, respectively. The Brake Mean Effective Pressure (BMEP) of B30 + DPA100 has been found to be 3.91% and 1.3% higher than diesel and B30, respectively. The Brake Specific Fuel Consumption (BSFC) was 8.68% lower than B30 but 1.49% higher than diesel. Overall, these findings suggest that B30 + DPA100 can be used in diesel engines without modification, offering reduced NOx emissions.

Experimental study of the transient properties of a diesel and castor biodiesel blend in a mini boiler with the optimal combustion efficiency

The researcher looks into alternative fuels because petroleum fuel is becoming increasingly scarce and energy demand is rising as a result of population expansion. In this work, experimental investigation of the transient characteristics of castor biodiesel and diesel is conducted. Castor crude oil was extracted with a Soxhlet apparatus. The crude oil is then transformed into biodiesel using potassium hydroxide as a catalyst in the esterification process. Different experimental procedures are employed for the small boiler (VITOLA 200) to ascertain the combustion performance, emission characteristics, and thermal efficiency with regard to time for blends of 10%, 20%, and 30% castor biodiesel. The results are then compared to 100% diesel fuel combustion performances. By setting the boiler pressure, mass flow rate, and damper opening to 200 kPa, 1.25 kg hr−1, and 41/2, respectively, the experiment tests are carried out. The outcomes demonstrated that the antioxidant from moringa increased the stability of the castor biodiesel blend’s combustion, resulting in an increase in cetane number to 56.61, which was significantly higher than the minimum cetane number (37.55) required to have good ignition. Furthermore, the 30% castor biodiesel blend results in a boiler with a maximum thermal efficiency of 63.25%. Additionally, a 30% castor biodiesel blend can reduce CO2 and HC emissions by 27.53% and 15.2%, respectively. Since the boiler uses heavy fuels, the investigation found that gasoline can be substituted with a blend of castor biodiesel and moringa antioxidant fuel. This seems like a promising way to lower greenhouse gas emissions while simultaneously improving the boiler’s overall efficiency.

Experimental investigation on biodiesel–diesel blends in a single-cylinder DI diesel engine

The present study analyses the utilisation of biodiesel–diesel blends in a single-cylinder diesel engine. Biodiesel is prepared via conventional transesterification with standard conditions (60°C reaction temperature, 1% by wt. catalyst, 7.5:1 molar ratio and 120 min reaction time). The test engine utilised is a single-cylinder naturally aspirated direct injection diesel engine. The test engine is operated at 100% load with different engine speeds ranging from 1000 to 2400 rpm. Performance, combustion and emission characteristics were analysed at different engine speeds. The MB10 blend (10% biodiesel + 90% diesel) has resulted in higher brake power of 7.43%, lowered brake-specific fuel consumption and carbon dioxide by 7.49% and 7.6%, respectively. Also, it can be concluded that the MB10 blend lowered the smoke by 24% and hydrocarbon by 10.34% with respect to neat diesel. The MB20 blend resulted in a lowered CO profile than the CO profile of diesel fuel by about 0.84%. However, the MB10 blend’s average CO profile is improved by 1.97% than mineral diesel. These results are compromised with higher CO and NOx profiles of 2.4% and 8.9%, respectively.

Detection of gaseous pollutants emitted from engine powered by biodiesel and diesel mixtures

Nowadays air pollution has been regarded as a serious environmental problem. One of the main generators of air pollution is the transportation, since the gas combustion from various chemical species is emitted mainly in urban transportation, using mainly diesel fuel. The use of renewable fuels is an attractive alternative choice to reduce environmental impacts. Brazil stands out in the current world scene as a major of alternative energy producer. Brazilian government introduced a program that includes blends of biodiesel to diesel in order to reduce the environmental impact caused by air pollution. Therefore, this study aims to evaluate the emission of gaseous pollutants using a diesel engine bench with mixtures of B5, B10, B15, B20, B25 and B50 of biodiesel in diesel. For this type of analysis, the Infrared Analyser was used to detect CO2 in the range of 1.88 to 2.76 %, electrochemical sensors were used to detect CO in the range of 1161 to 1485 ppmv and NOx in the range of 213 to 351 ppmv.

Amplifying performance attributes of biodiesel–diesel blends through hydrogen infusion and graphene oxide nanoparticles in a diesel engine

Amplifying performance attributes of biodiesel–diesel blends through hydrogen infusion and graphene oxide nanoparticles in a diesel engine

Evaluation of the Rate of Reduction of Greenhouse Gases from Diesel Engine Powered with Jatropha Curcas Seed Oil Blend Diesel

As part of the effort to reduce greenhouse gases emissions and lower its negative effects on climate change, this study was conceived with the aim of evaluating the rate of reduction of greenhouse gases emission from diesel engine powered with Jatropha Curcas seed oil blend diesel. The study produced biodiesel from the oil extracted from the Jatrophha Curcas seed using trans-esterification method. The amount of CO2, SO2 and NO2 emitted from a diesel engine powered with conventional oil and jatropha biodiesel blend were determined to ascertain whether there was reduction or increment in percentage of emissions. Laboratory analysis of Jatropha Curcas oil shows that 131.9524g jatropha curcas seed yielded 90.559ml of biodiesel and 41.2437ml of glycerol. Conventional diesel and Jatropha curcas biodiesel produced has similar physiochemical characteristics confirmed through ASTM(US) and DIN(EN) hence their combustibility. CO2 emissions increased with increase in diesel at B100 and B50 while it decreases in B20 and B40. While NO2 emissions increased by 1% in all the revolutions per minute, SO2 was only detected at B100 and B50 emission of the greenhouse gases. From the questionnaire survey conducted at Egbema, it was found that gas flaring has serious adverse effect on vegetation in the area, significant negative effect on the economy of the area due to the rise in air pollution. The result of the laboratory experiments showed that blended green diesel reduces the emission of greenhouse gases from combustion of diesel. The study recommended adoption of renewable energy sources for the operation of the oil firms in Egbema the study therefore concluded that blended green diesel is a promising alternative fuel for internal combustion engines.

Effect of Di-tert Butyl Peroxide on Diesel Engine Performance Fuelled by Biodiesel Blends

This study is motivated by the fact that the vegetable oils are being considered as the fuel of the future for the internal combustion engines, especially the compression ignition engines which are working with diesel as fuel. Different approaches for using the vegetable oils in CI engines as fuel are either to modify the oils to match with that of diesel to run successfully with these oils. Fuel additives are compounds formulated to enhance the quality and efficiency of the fuels used in motor vehicles. There are several benefits associated with the use of fuel additives. Di-tert butyl peroxide (DTBP) is effective for enhance the quality and efficiency of the fuels used in CI engine. The investigation was to check the feasibility of di-tert butyl peroxide as an additive in different blends of diesel and jetropha bio-diesel on engine performance. The short-term tests on an unmodified diesel engine were conducted using the bio diesel and di-tert butyl peroxide blends (0, 10, 20, 30, 40, 50, and 100 per cent and 0, 0.5, 1.0, 1.5, 2.0, 2.5 per cent) with diesel. The engine performance and emission characteristics were measured during the short-term test. In all types of fuel, with increased percentage of load, brake specific energy consumption (BSEC) of the engine was observed to be decreased, on the other hand brake thermal efficiency, fuel consumption rate, sound level (db.), exhaust temperature, and the engine exhaust emissions like CO2, CO, HC and NOx was increased, respectively.

Performance Evaluation of a 3.5 kW Diesel Engine Fueled with Blended Biodiesel of Mustard Oil

In this investigation, methyl ester of Mustard oil was prepared by trans esterification using solid potassium hydro-oxide as catalyst and used in a 3.5kW single cylinder four stroke diesel engine. Tests were performed at different load conditions and the per-formance was analyzed for B5 to B30 blends of Mustard biodiesel and pure mineral diesel. It was concluded that the lower blends of biodiesel enhance the break thermal efficiency and reduce the fuel consumption. It is proved that the use of biodiesel (produced from Mustard oil) in compression ignition engine is a viable substitute to diesel.

Performance Evaluation of a 5 hp Diesel Engine Fueled with Blended Biodiesel of Benola Oil

In this communication, methyl ester of Benola oil was prepared by transesterification using solid potassium hydro-oxide as a catalyst and used in a 5 hp single cylinder four stroke diesel engine. Tests were performed at different load conditions and the performance was analyzed for B5 to B30 blends of Benola biodiesel and pure mineral diesel. It was concluded that the lower blends of biodiesel enhance the brake thermal efficiency and reduce fuel consumption. It was also noticed that it reduces carbon pollution but slightly increases the NOx.

Effects of ethanol addition to diesel–biodiesel blends on the CI engine characteristics

This research work investigates the effects of adding ethanol to biodiesel–diesel blends on the performance and emissions of a single-cylinder, four-stroke, air-cooled compression-ignition engine. The engine was half-loaded within a speed range of 1000–2500 rpm. Four different fuel blends are considered: B0 (no biodiesel or ethanol), B10 (10% biodiesel), B10E2.5 (10% biodiesel with 2.5% ethanol), and B10E5 (10% biodiesel with 5% ethanol). The findings show that adding biodiesel slightly affects the engine power at low and medium speeds but increases power by approximately 6% at high speeds. Ethanol addition has a more significant impact, with an increase in engine power of 16% at 1700 rpm and 13% at 2500 rpm for 2.5% and 5% ethanol blends, respectively. All blends show an increase in brake mean effective pressure (BMEP) compared to B0, with the maximum enhancement observed in B10 with an average increase of 13% across all speeds. Specific fuel consumption is reduced with both biodiesel and ethanol addition, with a slight advantage for biodiesel, particularly at low and medium speeds. Thermal efficiency shows a reverse behaviour, with a small negative impact of ethanol addition. Biodiesel addition significantly increases carbon monoxide (CO) emissions, reaching an average of 190% across all speeds. However, adding ethanol helps mitigate this increase, especially at low and medium speeds, with an average decrease of 32% for a 2.5% ethanol blend compared to B0. Carbon dioxide (CO2) and nitrogen oxides (NOx) emissions are reduced with biodiesel addition and further reduced with ethanol addition. Overall, CO2 and NOx emissions are reduced with both biodiesel and ethanol addition.

A Review on the Influence of Additive Blended Biodiesel to the Performance and Emission Characteristics of Heavy-Duty Diesel Engines

Modern industrial society is heavily dependent on energy. The amount of energy needed to sustain a society increases as the world's population grows and transportation systems improve. However, the stringent emissions regulations enacted to control the number of harmful exhaust pollutants from heavy-duty diesel engines are likely to gradually phase out internal combustion engines that run solely on petrochemical fuels. This challenge puts constant pressure on researchers to seek improved fuel technologies that meet emission standards while reducing costs and emissions. In this paper, the impact of biodiesel blends, with or without additives was found to have both positive and negative effects on heavy-duty diesel engines. Biodiesel blends with additives such as 50% biodiesel 400mg/l additive and 100 % biodiesel 500mg/l additive have the potential to reduce emissions of harmful pollutants such as particulate matter (PM), carbon monoxide (CO), and hydrocarbons (HC). However, the impact on nitrogen oxide emissions is less clear and may depend on engine type and operating conditions. Regarding engine performance, additive biodiesel blends exhibited lower power and torque output and slightly lower fuel consumption than conventional diesel. On the other hand, non-additive biodiesel blends such as 5%, 10%, and 20% biodiesel in conventional diesel showed higher nitrogen oxide emissions and fuel consumption, but a reduction in HC and CO emissions. Overall, the use of additives in biodiesel blends can improve certain properties, such as cold weather performance and oxidation stability but the effect largely depends on engine design, operating conditions, and the percentage of additives used. Hence, more research is needed to fully understand the effect of biodiesel blends and additives on heavy-duty diesel engines and optimize their use for maximum benefits.

Effect of biodiesel on environmental impacts of diesel mechanical power generation by life cycle assessment

The novel goal of the present research is to integrate response surface and life cycle assessment methods to reduce the environmental impacts of mechanical power generation in a diesel engine fueled by diesel-biodiesel blends. Environmental impacts of mechanical power generation in an OM 314 diesel engine under the effect of biodiesel were investigated using the life cycle assessment method. Response surface methodology was used to find the optimum percentage of alga biodiesel in diesel-biodiesel fuel blends under the effects of different engine loads and speeds. In the optimization process, the dependent variables were engine performance characteristics and emissions. A blend containing 57 % diesel and 43 % biodiesel was found as the optimum fuel blend. The environmental impacts of the optimum diesel-biodiesel blend were calculated by the CML-IA baseline impact assessment model and compared with those of pure diesel and pure biodiesel. The results showed that the values of abiotic, abiotic fossil fuel, and ozone layer depletion indicators decreased by 16.09–44.09 % compared to pure diesel. Also, the values of other indicators decreased by 16.74–131.84 % compared to pure biodiesel. Normalization process showed that the marine aquatic ecotoxicity was the main indicator for all studied fuels.