Standard Diesel Research Articles

Experimental investigation on fuel properties and engine characteristics of biodiesel produced from Eruca sativa

This paper aims to consider the potential of Eruca sativa (ES) crops, which is a plant with a short production cycle and drought tolerance, for biodiesel feedstock source and to compare exhaust emissions and engine performance of using its biodiesel blends with pure diesel. Thus, ES methyl ester was produced through a transesterification reaction by using KOH as a catalyst. The fatty acid composition of ES biodiesel was determined by FTIR and GC–MS analysis and its properties were compared with ASTM biodiesel standard and regular diesel. The GC–MS analysis showed that oleic and palmitic acids were the main compounds in ES methyl ester. Then, biodiesel blends were injected into a single-cylinder 4-stroke diesel engine at various speeds. Experimental tests revealed that using ES methyl ester led to reductions in HC and CO emissions substantially and NOx emissions moderately, whereas there was a minor rise in CO2 emissions. Moreover, a slight decrease in engine power and an increase in specific fuel consumption (5.3%) occurred, which are acceptable due to the reduction of exhaust emissions. Based on the results, ES biodiesel has the capability to apply in CI engines and to diminish emissions.

Experimental performance investigation of Partially Stabilized Zirconia coated low heat rejection diesel engine with waste plastic oil as a fuel

ABSTRACT This experimental analysis is carried out to investigate the performance, emission, and combustion characteristics of partially stabilized zirconia (PSZ) coated compression ignition engine using waste plastic oil (WPO) as a fuel. The preparation and thermophysical properties of WPO are analyzed and found that the properties of fuel derived from the waste plastic merely similar to diesel fuel. The performance enhancement of WPO with low heat rejection (LHR) is conducted in direct ignition (DI) engine and compared with standard diesel fuel. From the results, we observe that the engine working with WPO+LHR show the evidence of higher thermal efficiency at the rated power. Surprisingly, the level of NOx emission tends to reduce with increasing load condition irrespective of fuel used. The WPO+LHR engine at full load condition emits <18.53% NOx, and around 10.67% of increment in the in-cylinder peak pressure when compared to the engine with standard diesel fuel (SDF). It is also found that the presence of unburnt hydrocarbon is reduced by about 14.75% compared to the SDF. The WPO and WPO+LHR fueled engines release the maximum amount of heat rate viz. 18.17% and 23.30% higher than that of diesel.

Reactivity of Standard Diesel Particulate Matter with NO2 under Different Operating Conditions

Nowadays, diesel vehicles include exhaust treatment technologies, such as diesel particulate filters, to meet the emission limitations of soot. Within the particle trap, soot can be oxidized by int...

COMBUSTION ANALYSIS OF CI ENGINE FUELLED WITH ALGAE BIOFUEL BLENDS

Algae-based biofuels are the most capable solutions to energy catastrophe and global warming for years to come due to its potentially high yield, higher growth rate, biodegradable, nontoxic, carbon neutral, low emission profile, use of non-arable land and non-potable water with less attention and resource consumption. A biofuel produced from chlorella algae oil through a transesterification process was used in this study. Experimental tests were performed on a single cylinder, four stroke, direct injection, naturally aspirated diesel engine at constant engine speed of 1500 rpm and compression ratio of 18 at various loading conditions to evaluate the performance, emission, and combustion characteristics using algae biofuel blends of 5%, 10%, 20%, and 30%, moreover the results are compared with those of standard diesel. The brake thermal efficiency showed decreasing trend (upto 5%) whereas specific fuel consumption (upto 7%) and exhaust gas temperature (upto 3%) showed increasing trend for algae biofuel blends compared to diesel. Reduction in hydrocarbon (upto 28%) and carbon monoxide (upto 22%) emission was noted for algae biofuel blends along with a marginal increase in NOx (upto 13%) emissions. Also, algae biofuel blends showed almost comparable combustion results compared to conventional diesel, however, the blends confirm shortened ignition delay due to their earlier start of combustion. From this study, we can conclude that small fraction by volume (20%) of algae biofuel addition with diesel has exhibited satisfactory results and could be used as a good substitute for petrodiesel fuel.

Influence of cetane-detergent additives into diesel fuel with RME content increased to 10% on the parameters of indicator diagrams and rate of heat release in a diesel engine

This publication is the next part of the article “The influence of cetane-detergent additives in diesel fuel increased to 10% of RME content on energy parameters and exhaust gas composition of a diesel engine”. The cause-effect analysis of the phenomena related to the impact of 3 additive packages used in diesel oil with RME content increased to 10% (compare to standard diesel fuel with 7% of RME) was described. The basis for the analysis of the impact of the tested fuels on energy parameters and composition of exhaust gases were the parameters of indicator diagrams and heat release parameters. It was found that the first set of additives affects the delay of auto-ignition of fuel and kinetic fuel combustion speed only at low engine loads. In this range of engine operation the NOx concentration in the exhaust gas is low and besides there is a large of EGR.The second additive package was operated at high engine loads but its impact on the lower self-ignition delay was quantitatively small. Therefore, in the third packet of additives, the amount of additives used in the second packet was doubled. Then a satisfactory shortening of the self-ignition delay and reduction of the max rate of kinematic heat release was achieved as a reason of a reduction of NOx concentration in the exhaust up to 8% (compared to the reference fuel).

Experimental Evalution of Palmyra Oil Blends in VCR Diesel Engine by using EGR Systems.

In present days industries are growing at a rapid rate and so as the usage of the diesel. The fossil fuels are limited in nature, the increased usage of diesel is resulting in the depletion of its reserves this gives rise to the need of alternative fuels. Due to low specific fuel consumption and supreme power efficiency it has vast applications compared to other fuels but NOX and smoke has seriously causing problem to environment. For this the Palmyra oil has same properties of diesel with varying compression ratios effects the performance and emission characteristics are evaluated. In this process step wise increase of CRs from 16 initially .Then increases EGRs of 0%,5% and 10% and studied performance and emission characteristics. There is improvement in engine efficiency during EGR increment and at low load .There is simultanesly decrease in NOX emissions . The single cylinder four stroke variable compression performance and emissions can be varied.. when fuel is pure diesel,b15and b35 of Palmyra oil is examined and bear with standard automobile usable diesel was conducted at compression ratio of 16:1 at the degrees of 19 and 23 degrees. The influence of Palmyra oil like compression ratio on fuel consumption ,brake thermal efficiency and exhaust gas emissions like NOx and hc has been investigated .the overall optimum is found to be b15 biodiesel –diesel blended for compression ratio of 16 at different exhaust gas recirculation such as 0, 5 and 10. The same experimentation is done for other blends B15 and B35 with palmyra oil. All the values are compared with each other. The configuration which achieved highest Break thermal efficiency is compared to the common diesel engine configuration used and the advantages and the disadvantages are listed out.

Potentials to simplify the engine system using the alternative diesel fuels oxymethylene ether OME1 and OME3−6 on a heavy-duty engine

Polyoxymethylene dimethyl ether (POMDME or OME) is an emerging synthetic oxygenated fuel indicating high potential to meet the increasing challenges of CO2-neutrality and sustainability. The excellent ignitability and the sootless combustion of OME are ideal properties for its application in diesel engines. However, since other properties are fundamentally different compared to conventional diesel fuels, both its combustion behavior and necessary adaptations of standard diesel engine components and materials have to be studied in detail to realize all advantages of this fuel.In the present work, the combustion and emission characteristics have been compared between different neat OME fuels and a reference paraffinic diesel fuel (PDF) varying several operating parameters of a single cylinder heavy duty research engine. To evaluate the performance of unmodified nozzles, a variation of increasing load has been considered. Moreover, the NOx reducing potential of the sootless OME combustion has been investigated by increasing exhaust gas recirculation (EGR) up to stoichiometric conditions and evaluated considering thermal efficiency and different strategies for exhaust gas aftertreatment. Furthermore, it has been studied whether different OME fuels could realize a simplification of the fuel injection system by varying the rail pressure and injection pattern. Finally, in order to find an OME compatible sealing material the change in weight of several samples dipped in different OME fuels have been investigated.It is shown that ethylene propylene diene rubber (EPDM) is an alternative sealing material for an engine operation only with long-chained OME. In addition, it is proven that the particle emissions of the OME combustion are comparable to citys immission level regardless of significantly increased EGR rates or very low injection pressures. However, the emissions of methane rise drastically at stoichiometric conditions independent of molecules chain length of the used OME fuel. Moreover, it is demonstrated that an injection strategy using only a main injection could be possible, if the engine is operated with long-chained OME fuels.

Experimental study of NOx and CO2 emissions at load regimes for a passenger car powered by direct injection diesel engine

The paper presents a study of NOx and CO2 emissions for a standard diesel direct injection engine, which equips the Renault-Dacia Solenza 1.9D-SDI cars. The different pollutions levels are analysed between idling regimes and medium and high loads at different speeds and transmission gearboxes. To simulate the load regimes, chassis dynamometer V-Tech Dyno VT-2/B1 was used. The exhaust gases were taken to various operating modes on the chassis dynamometer, specific regimes in urban and extra-urban mode. In the paper, some recommendations are made on operating regimes that would ensure the functioning of the car at a lower polluting level.

Effects of low-pressure EGR on gaseous emissions and particle size distribution from a dual-mode dual-fuel (DMDF) concept in a medium-duty engine

The application of a low-temperature combustion concept, such as RCCI combustion under real engine operating conditions is extremely complex. However, the implementation of the dual-mode dual-fuel (DMDF) strategy allows operating in low-medium load with the RCCI combustion and in high load with dual-fuel diffusive combustion. This allows taking advantage of the benefits of RCCI combustion as the simultaneous reduction of PM and NOx emissions. However, there are still serious challenges that required to solve, such as the high-pressure rise rate and the excessive CO and HC emissions. In this sense, this work shows how the implementation and an adequate adjustment of the cooled LP-EGR rate significantly minimize these problems and also shows how the LP-EGR has a greater impact on the DMDF than on the CDC concept.This work has been performed in a modern medium-duty diesel engine fueled with standard gasoline and diesel fuels, with which a cooled LP-EGR loop has been coupled. A TSI Scanning Particle Sizer (SMPS 3936L75) was used to measure the particles size distribution and the Horiba MEXA-ONE-D1-EGR gas analyzer system to determine gaseous emissions. A parametric variation of the LP-EGR rate was experimentally performed to analyze the effect over each combustion process that encompasses the DMDF concept (fully premixed RCCI, highly premixed RCCI and dual-fuel diffusion) and its consequent impact on gaseous and particle emissions. In addition, results were compared against the CDC concept to state the benefits of the DMDF concept. Among the different results obtained, it can be highlighted that during the RCCI strategy the increase in LP-EGR rate provided a reduction in NOx emissions. Nonetheless, unlike that fully premixed RCCI in highly premixed RCCI combustion, the PM emissions increased with this increment in the LP-EGR rate, shifting the size distribution of particle toward larger sizes, but decreasing the HC and CO emissions. Finally, with the exception of the high HC and CO emissions in fully premixed RCCI, in all the combustion strategies of the DMDF concept, a reduction of the analyzed pollutants was observed when compared with the CDC mode.

Comparative study of using multi-wall carbon nanotube and two different sizes of cerium oxide nanopowders as fuel additives under various diesel engine conditions

This research reports the study of using Cerium oxide (CeO2) nano additive with two different sizes (25 nm and 50 nm) blended with standard diesel fuel (DF-Ce25 and DF-Ce50) at various engine speed and load conditions. Moreover, carbon nanotube (CNT) is employed as a single additive (DF-CNT). Results indicate that the in-cylinder pressure of DF-CNT is slightly lower than that of DF under the most conditions due to more heat absorption during the evaporation process. In contrast, the in-cylinder pressure of DF-Ce25 and DF-Ce50 is higher than that of DF at relatively low speed due to the improved fuel spray and faster combustion. In terms of emissions, all fuels with nano-additives are overall lower than DF. DF-CNT can reduce CO, HC, NOx and PN by 20%, 22.6%, 21% and 5.5% respectively compared with DF, due to its improved spray and lower combustion temperature. Meanwhile, DF-Ce25 and DF-Ce50 produce the overall higher level of emissions of CO, NOx and HC than DF-CNT except for PN. A minimum engine (load-speed) limit and a maximum engine limit are found for CO emissions. Furthermore, DF-Ce25 emits higher NOx and lower HC than DF-Ce50, because CeO2 of 25 nm has a higher reaction rate of CeO2 due to its larger surface area and in return hinders the reaction of Ce2O3. The difference of PN emissions between the two sizes of CeO2 is the comprehensive result of the oxidization of particulate matters and the aggregation of unburnt fuel.

Performance of agricultural tractor consuming diesel and biodiesel derived from babassu (Orbinya martiana)

Biodiesel is an alternative fuel to diesel engines. This study aimed to evaluate fuel consumption and smoke density of agricultural tractors fueled by biodiesel, diesel, and biodiesel/diesel mixtures in a tilled field. Treatments consisted of distilled methyl ester (biodiesel) of babassu (Orbinya martiana) and seven combinations of it with two standard diesel fuels (B S1800 and B S50). The blending ratios were 0, 5, 15, 25, 50, and 100% biodiesel in diesel oil (B0, B5, B15, B25, B50, and B100, respectively). Regarding the results for hourly volumetric consumption, no difference was found between B0 and B100 when using B S1800, whereas an 8% increase was observed when using the S50. The weighted hourly consumption increased by 11.29 and 16.9% from B0 to B100 using B S1800 and B S50, respectively. Similarly, the specific fuel consumption increased by 11.1% and 14.3% from B0 to B100 using B S1800 and B S50, respectively. Yet, when comparing B0 and B S1800, the smoke density reduction was 68.6% and between B S50 and B100 was 58.0%. Our findings show that babassu biodiesel is a suitable substitute for diesel oil, without causing any damage to the tractor's engine.

Performance, emission and combustion characteristics of low heat rejection diesel engine using waste cooking oil as fuel

In this work, waste cooking oil (WCO) was used as fuel in standard and low heat rejection (LHR) diesel engines. The experiments were conducted in standard and LHR engine to measure the performance, emission and combustion characteristics using WCO and diesel as fuels. The brake thermal efficiency was found to be 26.5% for LHR engine with diesel compared to 26% of a standard diesel engine. A significant reduction of smoke and hydrocarbon emission with LHR diesel engine for diesel and WCO as fuels. The CO emission was decreased with LHR diesel engine at higher engine loads. At maximum load, peak in-cylinder pressure of 55 bar observed for standard diesel engine fuelled with diesel as fuel compared to 53 bar with WCO. The ignition delay and rate of pressure rise were found lower with LHR engine.

Exergy analysis and nanoparticle assessment of cooking oil biodiesel and standard diesel fueled internal combustion engine

In this paper, the exergy analysis and environmental assessment are performed to the biodiesel and diesel-fueled engine at full 294 Nm and 1800 r/min. The exergy loss rates of fuels are found as 15.523 and 18.884 kW for the 100% biodiesel (BDF100) (obtained from cooking oil) and Japanese Industrial Standard Diesel No. 2 (JIS#2) fuels, respectively. In addition, the exergy destruction rate of the JIS#2 fuel is found as 80.670 kW, while the corresponding rate of the BDF100 is determined as 62.389 kW. According to environmental assessments of emissions and nanoparticles of the fuels, the biodiesel (BDF100) fuel is more environmentally benign than the diesel (JIS#2) fuel in terms of particle concentration and carbon monoxide and hydrocarbon emissions. So, it is better to use this kind of the 100% biodiesels in the diesel engines for better environment and efficiency in terms of the availability and environmental perspectives.

Research on the Comparisons between Sabah Cycle and Diesel Cycle of Common Rail Injection Diesel Engine

Pressure constant pre-expansion ratio has directly influenced on the highest temperature of Diesel cycle. The common rail injection system also has directly influenced on the highest temperature and pre-expansion ratio, thereby it also affects the technical indices, such as thermal efficiency and average valid pressure. Taking National VI emission standard diesel from Weicai Company as an instance, the highest temperature and other technical indices of Sabah cycle with a common rail injection system and Diesel cycle without a common rail injection system were compared.

Co-pyrolysis of sugarcane bagasse and polystyrene with ex-situ catalytic bed of metal oxides/HZSM-5 with focus on liquid yield

Catalytic co-pyrolysis of sugarcane bagasse (SCB) and polystyrene (PS) was conducted in a fixed bed reactor over microporous HZSM-5, mesoporous metal oxides (MgO, CaO) and their blends to examine the effect on pyrolytic liquid yields and quality. Though the catalyst addition decreased the liquid yield, improvement in mono-aromatic hydrocarbon yield with the least content of oxygenates was achieved in the catalytic trials. Results revealed that HZSM-5 showed maximum conversion efficiency of acids, furans and phenols acting as hydrocarbon source for aromatic production. Basic MgO, with acidic HZSM-5, was found to conduce better catalytic performance yielding improved oil quality compared to HZSM-5:CaO catalyst. Mass ratio of 1:3 HZSM-5:MgO exhibited most eminent synergistic effect with maximum (56.8 wt%) mono-aromatic hydrocarbon (MAH) yield and lowest (20.8 wt%) poly-aromatic hydrocarbon (PAH) content. Additionally, increased calorific value and density upgradation comparable to standard diesel fuel quality were observed in the presence of dual catalyst layout.

Airport emission particles: exposure characterization and toxicity following intratracheal instillation in mice

BackgroundLittle is known about the exposure levels and adverse health effects of occupational exposure to airplane emissions. Diesel exhaust particles are classified as carcinogenic to humans and jet engines produce potentially similar soot particles. Here, we evaluated the potential occupational exposure risk by analyzing particles from a non-commercial airfield and from the apron of a commercial airport. Toxicity of the collected particles was evaluated alongside NIST standard reference diesel exhaust particles (NIST2975) in terms of acute phase response, pulmonary inflammation, and genotoxicity after single intratracheal instillation in mice.ResultsParticle exposure levels were up to 1 mg/m3 at the non-commercial airfield. Particulate matter from the non-commercial airfield air consisted of primary and aggregated soot particles, whereas commercial airport sampling resulted in a more heterogeneous mixture of organic compounds including salt, pollen and soot, reflecting the complex occupational exposure at an apron. The particle contents of polycyclic aromatic hydrocarbons and metals were similar to the content in NIST2975. Mice were exposed to doses 6, 18 and 54 μg alongside carbon black (Printex 90) and NIST2975 and euthanized after 1, 28 or 90 days. Dose-dependent increases in total number of cells, neutrophils, and eosinophils in bronchoalveolar lavage fluid were observed on day 1 post-exposure for all particles. Lymphocytes were increased for all four particle types on 28 days post-exposure as well as for neutrophil influx for jet engine particles and carbon black nanoparticles. Increased Saa3 mRNA levels in lung tissue and increased SAA3 protein levels in plasma were observed on day 1 post-exposure. Increased levels of DNA strand breaks in bronchoalveolar lavage cells and liver tissue were observed for both particles, at single dose levels across doses and time points.ConclusionsPulmonary exposure of mice to particles collected at two airports induced acute phase response, inflammation, and genotoxicity similar to standard diesel exhaust particles and carbon black nanoparticles, suggesting similar physicochemical properties and toxicity of jet engine particles and diesel exhaust particles. Given this resemblance as well as the dose-response relationship between diesel exhaust exposure and lung cancer, occupational exposure to jet engine emissions at the two airports should be minimized.

Reuse of waste animal fat in biodiesel: Biorefining heavily-degraded contaminant-rich waste animal fat and formulation as diesel fuel additive

Here we report a study on the technical feasibility of using purified animal fat as additive in a diesel fuel for internal combustion engines. The objective is to obtain a base fat with contaminant-free and ready to be diluted in petroleum diesel to obtain a diesel fuel blend with acceptable characteristics in terms of engine-system tolerances.A crude fat refining process composed of a vacuum distillation step and a glycerolysis step to convert the free fatty acids (FFA) recovered from distillation step into triglycerides (TAG) is used. Parametric study to determine the optimal purification-process conditions are used. The TAG obtained after a refining step, is then blended with standard diesel.A satisfactory formulation has already been used to power a system-equipped (converted) diesel engine, and blend ratio of up to 40% in standard diesel perform well enough to run the target engine.The results of this study show that this approach is technically feasible and economically interesting for recovering this waste into fuel. Moreover, it permits a decrease of the fuel carbon balance.

Environmental pollution cost analyses of biodiesel and diesel fuels for a diesel engine

In this study, Japanese Industrial Standard diesel no 2 and waste cooking oil biodiesel fuels are compared in terms of environmental pollution cost analysis. The experiments of the diesel and biodiesel fueled diesel engine are done at 100 Nm, 200 Nm and full load (294 Nm), while engine speed is constant at 1800 rpm. The method used in this study consists of a combination of economic and environmental parameters. According to the analyses, the total environmental pollution cost of the biodiesel is higher than the diesel fuel. On the other hand, the total cost of the CO2 emissions of the diesel fuel is generally found to be higher than biodiesel fuel in terms of the life cycle based environmental pollution cost. The specific environmental pollution cost is found as minimum at full load to be 2.217 US cent/kWh for the diesel fuel and 2.449 US cent/kWh for the biodiesel fuel at full load. On the other hand, the life cycle based specific environmental pollution cost is determined as minimum at full load to be 5.050 US cent/kWh for the diesel fuel and 5.309 US cent/kWh for the biodiesel fuel. The biodiesel fuel has higher values than diesel fuel in terms of the specific environmental pollution cost rates. The maximum total carbon dioxide emission rate is found as 0.2405 × 10−3 kg/kJ for the biodiesel fuel at 100 Nm engine torque and the minimum one is obtained as 0.1884 × 10−3 kg/kJ for the diesel fuel at full load. When the payback periods of the fuels are examined, biodiesel has longer period than diesel. The environmental payback period and life cycle based environmental payback period are also compared for fuels. In this context, the biodiesel has longer environmental payback periods rates than diesel. Consequently, the biodiesel fueled engine has higher environmental pollution cost rates than the diesel fueled engine, while the total carbon dioxide parameter of the diesel fuel is close to the biodiesel fuel's rate. Also, all of the other environmental parameters of diesel fuel is generally better than biodiesel. Consequently, the diesel fuel is generally better option than the biodiesel considering environmental aspects. For better environmental management, the diesel fuel utilization in the diesel engine is slightly better option than biodiesel fuel in terms of environmental pollution cost analysis.

Performance, combustion and emission characteristics on VCR multi-fuel engine running on methyl esters of rubber seed oil

This research work is proposed to test and evaluate the performance, combustion and emission characteristics of variable compression ratio engine fueled with methyl esters of rubber seed oil as biodiesel. Experiments are carried out on variable compression ratio engine by considering the compression ratio, load, fuel blends, injection pressure and supercharging pressure as variables. The response surface method prediction models for indicated mean effective pressure, brake thermal efficiency, specific fuel consumption, exhaust gas temperature, maximum combustion pressure, heat release rate, ignition delay, carbon monoxide, hydrocarbon and nitrogen oxides emission are developed using the experimental results. D-optimality test is carried out to get optimum engine-operating conditions with improved performance and emission. Test is conducted via the fuel blends of 20, 40, 60 and 80% biodiesel with neat diesel, with an injection pressure of 160 bar at a fixed compression ratio of 20 and at different supercharging conditions at 80% load. The results of the experiment are compared with that of diesel, which confirms that significant improvements in performance and emission characteristics are obtained with the help of supercharging. The combustion characteristics of biodiesel blends comprehend with that of standard diesel.

Environmental impacts of biodiesel production from waste spent coffee grounds and its implementation in a compression ignition engine

This study explores the environmental, economic, and technical feasibility of using spent coffee grounds as parent feedstock for biodiesel production. Biodiesel is produced from the spent coffee grounds, and four blends are prepared—B5, B10, B15, and B20. The effects of two extraction solvents (hexane and petroleum ether) on oil yields of the spent coffee grounds are investigated, employing the Soxhlet extraction technique. The properties of any intermediate yield throughout the production process are characterised and adjusted by post processes to ensure the conformity of the final biodiesel product with the standards (ASTM D6751 and ISO EN14214). The major part of the study investigates the effects of blends on tailpipe emissions and performance of a naturally aspirated single-cylinder compression ignition engine. A wide range of engine speeds (1600–3600rpm at 200-rpm increments) has been considered at three engine loads (100, 75, and 50%). The standard diesel fuel is set as a basis for comparison. Results show that the post processes on the extracted oil yielded water content of 0.038%, free fatty acid fraction of 0.41%, and acid number of <2mg KOH/g. The highest oil extraction (14.12%) was obtained over a 45-min extraction time using a hexane solvent. Biodiesel blends produced lower levels of CO2, CO, and HC. Blend B5 showed average reductions of 0.34, 12.5, and 4.23% at full load for the three aforementioned emissions, respectively; B10 reductions were 3.12, 29.85, and 19.14%, respectively. Higher levels of NOx emissions were detected from all blends. At full load, the average NOx increments of B5, B10, B15, and B20 were 0.35, 1.28, 1.8, and 2.3%, respectively. The outstanding environmental and ecological benefits of using the spent coffee grounds as a potential feedstock for biodiesel production are apparent.