Reduce Engine Emissions Research Articles

Optimization of Biodiesel–Nanoparticle Blends for Enhanced Diesel Engine Performance and Emission Reduction

Optimization of Biodiesel–Nanoparticle Blends for Enhanced Diesel Engine Performance and Emission Reduction

Enhancing biodiesel engine performance and emission reduction using Fe and Zn coated zeolite catalytic converters

ABSTRACT This study evaluates the performance and emission characteristics of diesel, fish biodiesel (comprising 20% fish oil and 80% diesel), and fish biodiesel using Fe and Zn-coated zeolite catalytic converters. The research aims to mitigate environmental challenges associated with diesel engines by exploring the efficacy of metal-doped zeolite catalysts in reducing harmful emissions. Fish biodiesel was derived from fish waste via transesterification and tested in a single-cylinder diesel engine. Key performance metrics, including Brake Specific Fuel Consumption, Brake Thermal Efficiency, Exhaust Gas Temperature, cylinder pressure, Heat Release Rate, and ignition delay, were measured. Emission characteristics such as carbon monoxide, hydrocarbon, nitrogen oxide, and smoke opacity were also analyzed. Results showed diesel had the lowest Specific fuel consumption, ranging from 730 g/kWh at 25% load to 320 g/kWh at full load. Fish biodiesel exhibited higher Specific fuel consumption, from 770 g/kWh to 350 g/kWh. Regarding emissions, the NOx of the biodiesel increased significantly compared to diesel; the use of a catalytic converter has reduced the NOx emission to a maximum extent of 37.5% at full load for a Fe-coated converter. The Zn-coated converter also improved emissions by up to 33% for NO but was slightly less effective than the Fe-coated converter. The study concludes that Fe-coated zeolite catalytic converters significantly enhance biodiesel-fueled diesel engines’ performance and emission characteristics. Both catalytic converters reduced the smoke emission significantly. These findings highlight the potential for developing more efficient and eco-friendly emission control technologies and promoting using renewable transportation fuels.

An Experimental Study on Algae Biodiesel with Nano-additives for Engine Performance and Emission Reduction

Introducing nano-additives like aluminum oxide and cerium oxide into the B20 blend biodiesel exhibited encouraging outcomes of combustion efficiency and emission reduction. These additives likely catalyzed combustion, leading to more complete fuel burn and lower emissions. Additionally, the presence of nano-additives might have facilitated better fuel atomization and distribution within the combustion chamber, resulting in enhanced engine performance. The results indicate that adding nano-additives to biodiesel blends has significant potential for reducing environmental impact and enhancing engine longevity and efficiency. Moreover, the utilization of nano-additives represents a promising avenue for addressing the dual challenges of energy sustainability and environmental preservation. By harnessing the synergistic effects of nano-scale materials, such as aluminum oxide and cerium oxide, in biodiesel formulations, engineers and researchers can strive towards developing cleaner and more efficient propulsion systems. This holistic approach underscores the importance of cooperation across disciplines between materials science, engineering, and environmental studies to advance the frontiers of sustainable energy technologies. The study attempted to improve combustion efficiency and reduce emissions by introducing nano-additives like aluminum oxide and cerium oxide into B20 biodiesel. The outcome showed enhanced engine performance, more complete fuel burn, and significant potential for reducing environmental impact.

Comparative Experimental Analysis and Performance Optimization of Single-Cylinder DI and HCCI Engine with Series Catalytic Converters

The stringent norms imposed by the government to reduce emissions to the environment have forced all engine manufacturers to reduce engine emissions. Carbon monoxide and NOx emissions from diesel engines are topics of significant consideration. This causes climate change and natural calamities. The current paper focuses on the comparative performance optimization of single-cylinder engines in DI and HCCI mode fitted with custom-designed catalytic converters in Series configuration using Taguchi regression Analysis based on experimental results obtained for series combination. The present work tested a diesel engine in both DI and HCCI modes with catalytic converters in series configurations with various monolith lengths and compression ratios. The test results are then analyzed using the Taguchi method and regression analysis. Overall, BTE is higher for HCCI mode than DI mode with the series arrangement of catalytic converters in the 24% to 35% range. Meanwhile, BSFC is lower for HCCI mode, in the 20% to 64% range. Hydrocarbon emission is higher, starting from 15% to 48%. The NOx emissions are lower for lower load, but on full load, they are more than those in DI Mode. CO emissions are also Higher for HCCI mode in the 12% to 30% range.

Influence of coconut and castor oil coating on engine intake non-woven filter performance

PurposeThis research focuses on the development and characterization of oil-wetted spun-bonded polypropylene (PP) non-woven filters for improved air intake systems in automobiles. The study aims to enhance engine performance, durability, fuel economy and emission reduction by addressing key aspects such as contaminants filtration efficiency, loading capacity, pressure drop, temperature performance and longevity.Design/methodology/approachThe research methodology involves the utilization of textile fabrics, particularly oil-wetted spun-bonded PP non-woven filters, renowned for their effective particle collection capability from intake air. Experiments were conducted using a Box–Behnken design with three variables – oil concentration, areal density and dust quantity – each at three different levels to establish correlations with the filter’s dust holding capacity (DHC) and pressure drop.FindingsThe findings indicate that immersing particles in oil-coated medium significantly enhances the filter’s DHC. Notably, castor oil as a coating demonstrates remarkable results, with a 97.53% increase in DHC and a high particulate matter filtration efficiency of 94.12%.Originality/valueThis study contributes to the originality of research by emphasizing the importance of oil density in determining the filter’s DHC and filtration efficiency. Furthermore, it highlights the superiority of castor oil over coconut oil-coated filter media, advancing air intake and/or filter systems for automotive engines.

Enhancing diesel engine performance and emission reduction through hydrogen enrichment in algal biodiesel blends.

The introduction of hydrogen into the engine could enhance its combustion efficiency and emission characteristics. The current study examines the attributes of compression ignition (CI) engines by introducing hydrogen into a biodiesel blend derived from algae. The improved thermal properties of hydrogen, when combined with algae biodiesel, significantly affect the performance, combustion, and emissions of dual-fuel engines. A study was conducted to evaluate the impact of hydrogen enrichment levels of 5%, 10%, 15%, and 20% of the nozzle volume on a biodiesel blend fuel. In comparison to diesel, algal biodiesel reduces emissions of unburned hydrocarbons (HC), carbon monoxide (CO), and oxygen (O2) by 5.19%, 3.61%, and 2.83%, respectively, while increasing nitrogen oxide (NO) emissions by 4.73%. In contrast to biodiesel, diesel demonstrated superior brake thermal efficiency (BTE) and lower specific energy consumption (SEC). Injecting hydrogen into A20 blend fuel at volumes of 5%, 10%, 15%, and 20% results in a respective increase in brake thermal efficiency of 2.65%, 2.97%, 3.50%, and 4.15%. The addition of hydrogen gas to biodiesel blends further enhances their combustion qualities, leading to elevated peak cylinder pressure, temperature, and heat release rate. The results indicate that A20H5, A20H10, A20H15, and A20H20 fuel reduced CO emissions by 3.75%, 8.75%, 12.5%, and 16.25%, respectively, compared to the A20 blend. In the same vein, HC emissions decreased by 5.76%, 10.29%, 15.52%, and 18.98%, respectively, as compared to A20 fuel. However, NO emissions rose by 5.36%, 10.20%, 15.28%, and 23.23%, respectively, for A20H5, A20H10, A20H15, and A20H20 test fuels. Ultimately, the utilization of algal biodiesel and hydrogen enrichment in diesel engines was proven to substantially reduce pollutants while increasing efficiency. This study contributes valuable insights into the intersection of renewable fuels, hydrogen enrichment, and engine technology, with the potential to drive significant advancements in sustainable transportation and environmental conservation.

Cavitation Phenomenon and Spray Atomization in Different Types of Diesel Engine Nozzles: A Systematic Review

<div>The high-pressure common rail fuel injection system for diesel engines is one of the core technologies that need to be addressed in the automobile industry. The control of the internal flow in multi-hole injector nozzles is the key to achieve accurate control of the fuel injection and spray process. There are various types of research on cavitation phenomena currently conducted on various types of test benches, but there is no conclusive discussion. Therefore, it is to summarize these studies in order to identify the highlights of existing studies and point out their shortcomings. This article compares and analyzes the developing patterns of cavitation phenomena on four test benches through literature review and has obtained rich research data on these four types of nozzles, but they still have their own shortcomings at the same time, even with numerical simulation. Based on this, the article has conducted a detailed and critical discussion on the current research situation and completed a summary. Specifically, it mainly involves four geometry parameters, two dynamic factors, and three fuel physical property parameters. The discussion conducted can contribute to the future development of cavitation models, further improving the energy-saving and -reducing emission reduction of diesel engines.</div>

Effects of Valve, Armature, and Armature Pin Guidance on Diesel Injector Performance

The valve, armature, and armature pin are critical factors influencing the hydraulic pressure differences in diesel injectors, and are essential for injection and backflow quantity control. These components play crucial roles in enhancing energy efficiency and reducing engine emissions. This experimental study investigated the effects of clearance between the valve, armature, and armature pin guidance. Forty-nine 2000 bar common-rail injectors (Bosch) were tested in calibrated stations. Injection quantities were assessed at both minimum and maximum operational pressures. Backflow rates were specifically examined at maximum pressure. A correlation matrix was created using Python to analyze the relationship between inputs and outputs, identifying dominant characteristics that define injector behavior. Increased injector precision correlated with reduced fuel consumption and enhanced energy efficiency. The study found that the effect of clearance between the armature and armature pins was more significant than that between the valve and armature. Injection quantities were observed to increase with pressure, and no critical difference in injection quantities was noted among different diameter groups at the minimum pressure point. Backflow quantities were consistent within groups when the armature–armature pin and valve–armature clearances were minimized.

Investigation on the combined effect of the hydrogen premixing and nanoparticle mixed pyrolysed oil of transformer oil waste in engine characteristics

In the world, the waste of one situation is the perfect requirement for the other situation. The value addition of the waste can produce new products which contribute to different applications. The electrical grid system produced the transformer oil wastes based on their use and capacity. This waste can be converted into useful applications in the CI engine by pyrolysis at 480 °C. This Pyrolysed oil of transformer oil waste (POTOW) is blended with diesel as a 1:3 contribution by volume for improved fuel properties. But it produced lesser performance. Therefore, the nanoparticles of Titanium dioxide and Silicon dioxide are added to the blend to generate the nano fuel. Enhanced performance and emission reduction are tried with 2–6 lpm hydrogen induction with the nano fuel in a 5.2 kW CI engine. Even though nanofuel produced better results, hydrogen induction was used to increase performance with reduced engine emissions further. At full load, 6 lpm hydrogen induction with the nanofuel produced 10.4% higher brake thermal efficiency, nearly 40% drop in CO, 39% drop in the UHC, and 22.22% drop in the smoke emission but 28% higher NOx emission compared to the petroleum diesel. Therefore, this combination is recommended for the CI engine operation with higher performance with reduced emissions and the transformer oil waste reduction in the environment of this application.

Effect of Intake Conditions and Combustion Factors on Gasoline and Diesel Engines Performance and Exhaust Emissions

The study aimed to investigate the effects of intake conditions, including water injection, filter presence, and temperature variations, on the performance of petrol and diesel engines. The experiment was conducted on single-cylinder four-stroke engines at varying speeds and loads. The composition of the exhaust emissions was analyzed to determine the combustion method. The results indicated that injecting a mixture of water and air into the engine inlet could reduce engine emissions by 17-33% and exhaust temperature by 13-35% for both engines. When an air filter and water injection were present, air flow restrictions in the air inlet led to better combustion and less unburned mixture due to increased air availability. The study also investigated the impact of combustion parameters on heat generation and emissions inside the combustion chamber of gasoline and diesel engines. The parameters studied included intake temperature, intake pressure, equivalence ratio, compression ratio, engine speed, turbulence kinetic energy, and combustion chamber design. The test results showed that higher intake temperatures lead to increased heat generation, increased overall engine efficiency, and reduced CO2 and NOx emissions in gasoline engines. Increasing the value of the parity ratio also led to improved overall efficiency of the two engines.

Research on the carbon emission reduction of internal combustion engines by reducing friction work

Research on the carbon emission reduction of internal combustion engines by reducing friction work

Enhancement of energy, exergy and soot characteristics with the utilization of MEK in diesel engine

This study investigated the effects of methyl ethyl ketone (MEK) on a diesel engine’s energy, exergy and emissions. The evaporation of a bi-component droplet of MEK and heptane was modeled. Furthermore, the soot morphology and nanostructure were quantified. Different blends were examined at other engine conditions. Running the engine under idle conditions and optimum speed considerably reduced engine emissions. MEK noticeably decreased the maximum reachable load of the diesel engine. Both specific fuel consumption and thermal efficiency increased with MEK. The exergetic efficiency increased while the fuel exergy decreased at the same work exergy. The effects of MEK on combustion characteristics were insignificant. However, a stronger premixed combustion phase was obtained where MEK evaporated first and caused a slightly longer droplet lifetime. Low percentages of MEK reduced CO emissions, while NOx emissions increased consistently with the MEK addition. The engine conditions noticeably influenced the unburned hydrocarbon emissions with MEK. Both smoke opacity and primary particle diameter decreased. The fringe analysis emphasized that MEK decreased fringe length, soot intensity, and alignment, increasing fringe tortuosity and spacing. Clearly, methyl ethyl ketone suppressed soot formation in a diesel engine and decreased its reactivity.Graphical abstract

Comparative analysis of PODE3 and PODE4 fuel additives for emission reduction and soot characteristics in compression ignition engines

Polyoxymethylene dimethyl ethers (PODEn) have been regarded as promising fuel additives in reducing engine emissions due to their extra oxygen content and absence of C–C bonds. This research compares the effectiveness of PODE3 and PODE4 as fuel additives (10 % oxygen content) in a compression ignition (CI) engine. The results show that PODE can retard the ignition delay and shorten the combustion duration. They can both reduce HC emissions, with PODE4 having the greatest reduction. Both additives comparably reduce NOx emissions while consuming similar oxygen amounts. PODE alters particle size distribution, favoring higher nucleation mode particles and reducing accumulation mode particles, especially for the case with Diesel/PODE3. Further, this study investigates the soot characteristics when with different fuel blends. Thermogravimetric analysis (TGA) reveals enhanced oxidative reactivity in soot when with Diesel/PODE3 and Diesel/PODE4 fuel blends. Raman spectroscopy shows reduced crystalline structure and increased crystalline width in soot when with PODE additives. Fourier transform infrared (FT-IR) spectroscopy indicates improved relative intensity of aliphatic C–H groups and intensified aromatic C–H groups with PODE addition. In summary, PODE3 and PODE4 are promising CI engine fuel additives, substantially reducing particulate matter (PM) emissions and enhancing soot reactivity. These findings hold significance for cleaner combustion technologies.

Development of a novel dual-loop optimization method for the engine electric turbocompound system based on particle swarm algorithm

Electric turbocompounding (ETC) plays a key role in fuel saving and emission reduction of internal combustion engines. In this paper, a novel dual-loop optimization method is proposed to rapidly obtain highest turbine efficiency and lowest engine BSFC. Firstly, turbine model and the engine cycle model are established and coupled in MATLAB. The predicted engine torque and BSFC are 4.48 % and 5.05 % deviated from the experimental data. The deviations of turbine swallowing capacity and efficiency are within 1 % and 2 %, respectively. Then, particle swarm optimization (PSO) is used to seek for the optimal ETC expansion/pressure ratio in the outer loop and the optimal turbine geometric parameters in the inner loop. It is shown that 3–4 particles are enough to obtain a good solution for the 2-D ETC system optimization and at least 25 particles are required for the 6-D turbine optimization. At last, case studies are carried out to analyze the impacts of ETC mechanical efficiency and back pressure. It is shown that 5 % higher of ETC mechanical efficiency results in 30 % increase in electric power and 10 kPa higher back pressure leads to 18.1 % lower in electric power. The optimized turbine can obtain efficiency higher than 78 % in all cases.

Investigation of the light-off characteristics and secondary pollutants production mechanism in Pd/Rh catalyst for natural gas engines

To investigate the influence mechanism of the light-off characteristics and secondary pollutants (N2O and NH3) of the Pd/Rh catalytic converter for natural gas engines, a global model of the catalytic converter and a more comprehensive catalytic reaction mechanism were first established. Further, the model and the catalytic reaction mechanism were validated by using experimental data. Then, the effects of exhaust temperature and exhaust composition (H2O, O2, and H2 concentrations) on the catalytic converters were investigated. The results showed that a higher temperature reduced the light-off time t50 of NO and CO. The production of N2O decreased to 0 at high temperatures due to the reduction reactions of R14 (N2O+H2 = H2O+N2) and R16 (N2O+CO = CO2 + N2). NH3 would form at the temperature above 825 K, and the required H2 originated from SR and WGS reactions. Increasing the H2 concentration promoted the conversion of NO and CO. When the temperature exceeds 600 K, increasing the H2 concentration decreases the production of N2O. H2O has the opposite effect on the production of N2O and NH3 at high temperatures. Increasing the content of H2O increased the conversion of NO and inhibited the conversion of CO. O2 concentration at 4000 × 10−6 is beneficial to reduce secondary pollutants of N2O and NH3. At the condition of 730–820 K and 4000 × 10−6 O2, the productions of N2O and NH3 were reduced to 0. This study contributes to the efficient application of Pd/Rh catalytic converters and further enhances the emission reduction of natural gas engines.

Evaluation of thermal management technologies for fuel efficient cold-start emissions reduction in diesel engines

The ultra-low NOx emission limits for heavy and mid-duty vehicles, which are expected to be imposed in both Europe and the USA by 2027, together with the enforcement of continuous decrease in CO2 emission levels, make the need for adoption of newer technologies in the automotive industry imperative. To achieve low tailpipe NOx emissions, the accelerated warm-up of the exhaust aftertreatment system is of great importance. On the other hand, the thermal management strategies applied for this purpose result in fuel consumption penalty and consequently higher CO2 as it can be widely found in the literature. Thus, the use and optimization of advanced thermal management technologies is critical to decrease the NOx– fuel penalty trade-off on the basis of complete driving cycles. In the present work an integrated modeled-based approach is implemented by coupling advanced, predictive 1D engine, and aftertreatment simulation models which are extensively validated via dedicated experimental data. The main goal of this approach is to define and investigate multiple engine or aftertreatment-based thermal management technologies, as well as a combination of them, creating a more efficient warm-up mode for the engine. Thermal measures such as cylinder deactivation, retarded start of the main injection, late intake valve closing (Miller cycle), intake throttling, elevated idle speed, and secondary fuel injection upstream the DOC are evaluated for their effect on the exhaust system heat-up time, the fuel consumption penalty and more importantly, for their impact on the tailpipe NOx emissions calculated by this holistic simulation approach.

Effect of different ammonia mixing methods for diesel ignition on combustion and emission performance of high pressure common rail engine

Ammonia is a zero-carbon fuel. Diesel/ammonia dual-fuel combustion mode can solve the problem of difficult compression ignition of pure ammonia. This article aims to explore the best mixing method and mixing ratio of ammonia fuel. The research results show that with the increase of the ammonia mixing ratio in the intake duct, the fuel consumption rate decreases by 7.71%. However, the serious ammonia escape phenomenon reaches a maximum of 37.35%, resulting in a serious decrease in power output. The cylinder temperature dropped by 197.12K, CO2 emissions decreased by 49.34%, NOx emissions decreased by 16.84%, and emissions significantly improved. When using direct injection ammonia mixing in the cylinder, as the ammonia mixing ratio increases, the explosion pressure in the cylinder decreases by 8.32%, the temperature in the cylinder decreases by 127.37K, the maximum ammonia escape is only 6.89%, CO2 emissions decreased by 88.10%, NOx emissions decrease by 75.90%, and CO2 and NOx emissions significantly decrease. Compared with the two ammonia blending methods, the direct injection ammonia blending method in the cylinder is obviously better. When the direct injection ammonia blending ratio in the cylinder is 70%, compared to the original engine, the diesel engine has the best working performance, increased power, and improved economy by 7.52%, and the proportion of ammonia escape is small. CO2 emissions are reduced by 69.05%, and NOx emissions are reduced by 29.22%. The research results of this article provide data support for achieving energy-saving, emission reduction, and low-carbon environmental protection of diesel engines.

A study on carbon dioxide emissions reduction in marine diesel engines using a chemical carbon absorber

A study on carbon dioxide emissions reduction in marine diesel engines using a chemical carbon absorber

Effect of early intake valve closing, exhaust gas recirculation and split injection on combustion and emissions characteristics of a HDDI diesel engine operating in PCCI combustion mode

Premixed Charge Compression Ignition (PCCI) combustion is an alternative to conventional diffusion-controlled combustion for Mono-nitrogen oxides (NOx) and soot emissions reduction in DI diesel engines. However, bringing the center of combustion (CoC) near top dead center (TDC) to reduce brake specific fuel consumption is challenging. In this study, for two Early Intake Valve Closing (EIVC) profiles of split injection strategy, combustion characteristics and emissions of a heavy-duty direct injection (HDDI) diesel engine are evaluated by CFD simulations. Combustion efficiency, Indicated Specific Fuel Consumption (ISFC), NOx, soot, and carbon monoxide (CO) emissions are evaluated for 40 ˚CA and 80˚CA EIVC timings with respect to the base diesel combustion with 0, 30, 50, and 70% Exhaust Gas Recirculation (EGR) rates at 3 bar Brake Mean Effective Pressure (BMEP).CFD simulations reveal that EIVC strategy can displace the CoC towards TDC up to 5–10 ˚CA depending on the EGR rate. Moreover, up to 30% NOx reduction can be achieved in EIVC cases. In 70% EGR case, lower ISFC and near zero NOx emissions can be obtained compared to conventional diesel combustion due to CoC being closer to TDC. However, the EIVC strategy with EGR increases CO emissions due to incomplete combustion of a lower air/fuel ratio mixture.

A novel finding on tribological, emission, and vibration performances of diesel engines linking to graphene-attapulgite lubricants additives under hot engine tests

The cylinder liner-piston ring (CL-PR) that worked under harsh conditions is extremely susceptible to wear, and its friction loss is the primary source of mechanical loss of engines, affecting its equipment reliability and energy consumption. Recently, the use of low sulfur fuel oils (LSFO) aggravated the wear of the CL-PR, further increasing friction loss. Furthermore, the emissions of diesel engines also affect the environment and human health. In this study, the graphene-attapulgite (G-ATP) additive was prepared and applied to engines in response to these challenges. The prepared G-ATP additive was dispersed into 5040 lubricating oil with a 0.25 wt% concentration, then the effects of the additive on engines were investigated under hot test conditions with a speed of 1750 rpm. It was found that the G-ATP additive displayed excellent tribological properties, the wear mass loss of the piston ring was reduced by 64.5% with the addition of the G-ATP additive, and the wear of the cylinder liner was significantly reduced. Meanwhile, owing to the excellent tribological properties and thermal conductivity of the G-ATP additive, the HC and NOx emissions of the engine were reduced by 3.0% and 6.1%, respectively. Additionally, the vibration performances of the engine were improved by 42.1% in the final stage. These findings revealed the potential mechanism of the G-ATP additive for performance enhancements of diesel engines, as well as the relationships between the emission and vibration of engines and tribological properties of CL-PRs, which promote the energy saving and emission reduction of engines.