Combustion Emissions Research Articles

Selenium and its mechanisms mitigate cadmium toxicity in plants: Promising role and future potentials.

Selenium and its mechanisms mitigate cadmium toxicity in plants: Promising role and future potentials.

Comprehensive research of some semi-volatile organic compounds (SVOCs) at very low levels in Lake and marine waters in Antarctica on-site by SBSE thermal desorption GC-MS/MS: Distribution, source apportionment, ecological and human health implication.

Comprehensive research of some semi-volatile organic compounds (SVOCs) at very low levels in Lake and marine waters in Antarctica on-site by SBSE thermal desorption GC-MS/MS: Distribution, source apportionment, ecological and human health implication.

Enhancing combustion performance and emission profiles using Citrullus colocynthis biodiesel blends with hydrogen

Enhancing combustion performance and emission profiles using Citrullus colocynthis biodiesel blends with hydrogen

Effects of nonextractable residual formation on the study of historical PAH pollution and source contribution in a lake sediment core.

Effects of nonextractable residual formation on the study of historical PAH pollution and source contribution in a lake sediment core.

Investigation of performance, combustion and exhaust emission characteristics of a CI engine using waste cooking biodiesel-hydrogen strategies: A trade-off analysis

Investigation of performance, combustion and exhaust emission characteristics of a CI engine using waste cooking biodiesel-hydrogen strategies: A trade-off analysis

Emulsifier-free B50 biodiesel-water-ethanol emulsion fuel: A study on combustion characteristics, fuel performance, and emissions

Emulsifier-free B50 biodiesel-water-ethanol emulsion fuel: A study on combustion characteristics, fuel performance, and emissions

Modeling of hydrogen blending natural gas combustion characteristics and emission analyses in industrial burners

Modeling of hydrogen blending natural gas combustion characteristics and emission analyses in industrial burners

Numerical simulation of predictive combustion and NOx emissions for different ammonia/hydrogen fuels in SI engine using zero-1 dimensional thermodynamic modeling

Numerical simulation of predictive combustion and NOx emissions for different ammonia/hydrogen fuels in SI engine using zero-1 dimensional thermodynamic modeling

Catalytic combustion efficiency and emission reduction of amorphous boron/lanthanum orthoferrite nano-hybrids in hydrocarbon fuels

Catalytic combustion efficiency and emission reduction of amorphous boron/lanthanum orthoferrite nano-hybrids in hydrocarbon fuels

Source characteristics and gas-particle partitioning of alkylated polycyclic aromatic hydrocarbons in coal combustion emissions

Source characteristics and gas-particle partitioning of alkylated polycyclic aromatic hydrocarbons in coal combustion emissions

Exhaust emission analysis of a motorcycle equipped with a Dual-Fuel Pertalite–LPG System under varying LPG flow rates and engine speeds

The increasing dependency on fossil-based fuels and the rise in vehicular exhaust emissions have intensified the search for environmentally friendly alternative fuels. This study aims to investigate the effect of varying liquefied petroleum gas (LPG) flow rates on the exhaust emissions of a motorcycle operating on a dual-fuel system combining Pertalite and LPG. Experimental tests were conducted on a four-stroke motorcycle with a manual transmission and a carburetor-based fuel system, under a range of engine speeds (1400–2000 rpm) and three LPG flow rates: 0.2, 0.5, and 0.8 L/min. The measured emission parameters include carbon monoxide (CO), hydrocarbons (HC), and carbon dioxide (CO2). The results demonstrate that an LPG flow rate of 0.5 L/min yields the highest CO2 emissions and relatively lower CO and HC levels compared to 0.2 and 0.8 L/min. In contrast, the 0.8 L/min flow rate exhibits signs of incomplete combustion, as indicated by elevated CO and HC emissions and a decline in CO2 concentration. The findings highlight the need for an optimal LPG flow rate to achieve efficient combustion and minimal emissions. The dual-fuel Pertalite–LPG system presents practical potential, particularly when integrated with a more advanced air–fuel ratio control system.

Computational Investigation of Advanced Compression Ignition with Wet Ethanol in an OP-2S

<div>Alcohol fuels have inherent properties that make them suitable candidates to replace conventional fossil fuels in internal combustion engines by reducing the formation of harmful emissions such as lifecycle carbon dioxide (CO<sub>2</sub>), nitrogen oxides (NO<sub>X</sub>), and particulate matter (PM). There is an increasing amount of work to use fuels such as ethanol or methanol in mixing-controlled compression ignition (MCCI) as a replacement for diesel fuel. However, employing these fuels in a strictly MCCI strategy results in an evaporative cooling penalty that lowers indicated fuel efficiency. This work proposes the use of an advanced compression ignition (ACI) strategy with a high autoignition resistant fuel, where a fraction of the fuel is premixed and autoignited in conjunction with a fraction of fuel that is burned in a mixing-controlled manner to achieve diesel-like efficiencies with significant emission reductions.</div> <div>A computational model for MCCI with diesel and wet ethanol in an opposed piston two-stroke (OP-2S) engine was validated against experimental data. Diesel and wet ethanol MCCI were then compared at a similar operating condition, where it was seen that wet ethanol provided a significant reduction in NO<sub>X</sub> emissions but resulted in a lower indicated efficiency. A triple injection strategy to enable ACI is then proposed by redesigning one of the injectors to enable compression stroke injections. The injector included angle, the injection split fractions, and injection timings of the triple injection strategy were varied to understand the impact of each on combustion performance and emissions. An optimal triple injection strategy based on simulation data was approximated and then simulated to compare to conventional diesel (i.e., MCCI with diesel) and MCCI with wet ethanol. ACI demonstrated a 3.5% point efficiency improvement over MCCI with wet ethanol, resulting in an efficiency that was the same as conventional diesel while still demonstrating nearly a 4 times reduction in NO<sub>X</sub> emissions.</div>

Multi-objective optimization of boiler combustion efficiency and emissions using genetic algorithm and recurrent neural network in 660-MW coal-fired power plant

Indonesia has demonstrated a firm commitment to achieving Net Zero Emissions (NZE) by 2060. The implementation of diverse strategies, such as the application of biomass co-firing technology in coal-based steam power plants, demonstrates this commitment. This study focuses on the 660 MW supercritical coal-fired boiler as the object of investigation. The key problem addressed in this research is the unstable combustion performance due to the dynamic and nonlinear interactions among operational variables under biomass co-firing conditions. These fluctuations can negatively impact boiler efficiency, CO2 emissions, and the plant’s capability factor. The study proposes a dynamic multi-objective optimization framework using a Recurrent Neural Network (RNN), Response Surface Methodology (RSM), and a Multi-Objective Genetic Algorithm (MOGA) to enhance performance reliability and support Indonesia’s transition to cleaner energy sources. The findings indicate that the RNN model exhibited superior prediction accuracy compared to the RSM, with a Root Mean Square Error (RMSE) value of 0.1523% for boiler efficiency, 1.6993% for CO2 emissions, and 0.5284% for the capability factor. The MOGA optimization exhibited an enhancement in boiler efficiency from 86.6793% to 87.32%, a reduction in CO2 emissions from 114.213 mg/Nm3 to 53.972 mg/Nm3, and an augmentation in the capability factor from 87.9% to 89.32%. Furthermore, coal consumption is reduced to 51,524 tons per hour, which can generate operational cost savings of IDR 1.34 billion per day. The RNN and MOGA-based approaches have been demonstrated to be more effective than RSM for optimizing boiler combustion. This method is important for developing a strategy to improve the efficiency of the combustion process in boilers in coal-fired power plants. It will also help support the transition to clean energy and achieve the NZE 2060 target

Combustion and Nitrogen Oxide Behaviors of Ammonia/Methane–Air Premixed Flames in a Model Gas Turbine Combustor: Model Validation and Numerical Investigation

Abstract This research presents a numerical analysis of the combustion and nitrogen oxide (NOx) emission characteristics of premixed ammonia/methane (NH3/CH4) swirl flames in a gas turbine combustor, aimed at supporting clean energy applications. Simulations were conducted at equivalence ratios of φ = 1.0 and 1.2 at varying ammonia doping ratios (NH3 by vol%) of 20%, 30%, 40%, and 50%. A detailed chemical mechanism consisting of 957 reactions and 128 species was integrated into a flamelet-generated manifold framework. The model validation showed strong agreement in temperature and species fields. The results show that increasing ammonia content leads to a reduction in the peak flame temperature, carbon monoxide, and carbon dioxide (CO2) emissions. For a 20% NH3 blend, the peak temperature reached 2206 K at φ = 1.0 and decreased to 2129 K at φ = 1.2. For a 50% NH3 mixture, peak temperatures were 2171 K and 2084 K, respectively. Increasing the ammonia fraction from 20% to 40% resulted in a CO2 reduction of 14.06% at φ = 1.0 and 18.05% at φ = 1.2. NOx emissions rose by 8.0% when ammonia content increased from 20% to 30% at φ = 1.0, but further increasing NH3 to 50% led to a 20% reduction. Overall, the highest NOx emissions were consistently observed at 30% NH3 and φ = 1.0.

A Comprehensive Study: Seasonal Variation of BTEX in Ambient Air of Aligarh, Uttar Predesh, India

Volatile organic control of the air quality in the cities is becoming an issue especially when referring to BTEX- Benzene, Toluene, Ethylbenzene, and Xylene as a result of rapid growth of cities and high traffic and industrial engagements in ambient air of Aligarh. The current research paper determines the seasonal variability of the ambient BTEX concentration in Aligarh, an urban expanding province in western Uttar Pradesh, India. Passive diffusion and complementary active air samples were conducted in one-year period and BTEX levels were analyzed in summer and monsoon seasons and winter seasons. Meteorological parameters were also measured at the same time as the BTEX concentrations of the gas phase was determined by gas chromatography with Flame Ionization Detection (GC-FID). The findings suggest that moderate concentrations of BTEX were the most popular finding at the presence of all the compounds, winter was the highest in both seasonal exceedances. The greatest rate of exceedance was 36% of benzene followed by toluene (30%), xylene (26%), and ethylbenzene (18%). It can be predicted seasonally with the colder months being of higher risk since the atmospheric mixing is less, and increased combustion emissions during colder months increase the health hazard. The study indicates that consistent air quality surveying is vital in tier-2 cities such as Aligarh and offers the much-needed fundamental information to make specific intervention actions and guidelines on environmental health in Aligarh City.

Investigating the effect of butanol isomers on combustion and emissions in port injection dual fuel diesel engines: an experimental study

The present study examines the effects of substituting alternative fuels for diesel fuel and employing a dual fuel approach on diesel engine combustion characteristics and emissions. Various butanol isomers, namely ıso-butanol, n-butanol, tert-butanol, and sec-butanol, were chosen as novelty alternative fuels. In dual fuel combustion strategy, diesel fuel was injected directly into the cylinder, while butanol isomers as a secondary fuel were introduced into the cylinder at the beginning of the intake period using a port injection technique. The tests were repeated for 15%, 30%, and 45% premixing ratios (Rp) of butanol isomers. This study presents detailed combustion parameters and pollutant emission findings produced in diesel engines employing a dual fuel strategy with butanol isomers. In general, an increase within in cylinder pressure and heat release rate was observed. Especially at a premixing ratio of 45%, an increase of 50% within heat release rate was observed. Use of all butanol isomers increased the ignition delay and shortened combustion duration. Brake thermal efficiency remained at acceptable levels, and ringing intensity was below the knock limit. In addition to an increase in CO and HC emissions, NOX emissions were also up at other premixing ratios but declined at 15%. High levels of decreased smoke opacity were recorded. Especially at a premixing ratio of 45% iso-butanol, a decrease up to 90% is remarkable. In conclusion, the combustion characteristics and pollutant emission results obtained from the experimental engine are discussed in detail according to the operating parameters. The obtained findings provide important information about the performance and emission profiles of alternative fuels and dual fuel systems and provide guidance for future research.

Altitude-Dependent Analysis of Combustion Performance and Emissions in a Commercial Aircraft Engine Leveraging Real Engine Data

Abstract This study provides a comprehensive numerical investigation of altitude-dependent combustion performance and emissions of a commercial aircraft engine, leveraging real engine data to evaluate kerosene-fueled operation across six flight levels: FL300, FL318, FL336, FL354, FL372, and FL390. The combustion chamber geometry was modeled using Siemens NX, simplified in ANSYS SpaceClaim, and meshed with a five-layer inflation strategy to ensure proper boundary layer resolution. A high-quality mesh was achieved, and a mesh independence study was conducted to ensure numerical accuracy. Using the realizable k–ε turbulence model with enhanced wall treatment and an eddy-dissipation approach for turbulence-chemistry interactions, the results show that lower flight levels are associated with higher combustion efficiency, with peak temperatures exceeding 2500 K at FL300. Conversely, higher altitudes demonstrated reduced combustion efficiency and increased unburned fuel fractions, providing insights into the performance and environmental impact of altitude-dependent aircraft operations. These results may assist in optimizing engine design and operational strategies for improved fuel efficiency and reduced environmental impact across varying altitudes.

Impact of Post-Injection Strategies on Combustion and Emissions in a CTL–Ammonia Dual-Fuel Engine

Ammonia is a carbon-free fuel with strong potential for emission reduction. However, its high auto-ignition temperature and low reactivity lead to poor ignitability and unstable combustion. In contrast, coal-to-liquid (CTL) fuel offers high cetane number, low sulfur content, and low aromaticity, making it a clean fuel with excellent ignition performance. Blending CTL with ammonia can effectively compensate for ammonia’s combustion limitations, offering a promising pathway toward low-carbon clean combustion. This study explores the effects of post-injection strategies on combustion and emission characteristics of a CTL–ammonia dual-fuel engine under different levels of ammonia energy fractions (AEFs). Results show that post-injection significantly improves combustion and emission performance by expanding ammonia’s the favorable reactivity range of ammonia and enhancing NH3 oxidation, particularly under moderate AEF conditions (5–10%) where ammonia and CTL demonstrate strong synergy. For emissions, moderate post-injection notably reduces CO at low AEFs, while NOX emissions consistently decrease with increasing post-injection quantity, with greater suppression observed at higher AEFs. Soot emissions are also effectively reduced under post-injection conditions. Although total hydrocarbon (THC) emissions increase due to ammonia’s low reactivity, post-injection mitigates this accumulation trend to some extent, demonstrating overall co-benefits for emission control. Comprehensive evaluation indicates that the combination of 5–10% AEF, 8–12 mg post-injection quantity, and post-injection timing of 10–15 °CA achieves the most favorable balance of combustion efficiency, emissions reduction, and reaction stability, confirming the potential of the CTL–ammonia dual-fuel system for clean and efficient combustion.

Environmental risk assessment of lignite storage in the mining industry: Strategies for hazard mitigation

This study evaluates risk factors in the mining industry, focusing on environmental hazards linked to lignite storage in bunker yards. Through SPSS analysis and employee feedback, it identified environmental risks as the most critical, with a mean risk rating of 3.82, emphasizing their high priority in risk management. The research notes significant environmental concerns with lignite storage, including large heaps prone to spontaneous combustion and hazardous gas emissions like carbon monoxide. Given carbon monoxide’s severe health risks, effective management is essential. Event Tree Analysis (ETA) using RAM Commander software revealed a high probability (P=0.507) of major environmental challenges. To address this, the study suggests introducing CO2 into coal storage areas to control toxic gas emissions and reduce spontaneous combustion risk, thereby maintaining the coal’s Net Calorific Value (NCV) and Gross Calorific Value (GCV). Additionally, the study examines the social and environmental impacts of land acquisition for mining, recommending the use of uncultivable land and underground mining techniques to minimize community displacement and land-related risks. In alignment with IS 14000 environmental management standards, the study supports these strategies and continuous ETA monitoring to enhance safety and reduce adverse environmental and community impacts.

The Role of Nanoparticles as Additives in Diesel/Biodiesel: A Review on Performance and Emission Enhancements

This paper presents a comprehensive review of recent advancements in the use of nanoparticles as additives in diesel-biodiesel blends to enhance engine performance and reduce emissions. Various preparation techniques, including ultrasonication and surfactant-assisted dispersion, are discussed to improve nanoparticle stability and fuel blend homogeneity. The review evaluates the effects of commonly used metal oxide nanoparticles such as TiO₂, Al₂O₃ and CeO₂ on brake thermal efficiency, fuel consumption and exhaust emissions, including reductions in CO, HC and NOx emissions. Among the nanoparticles studied, cerium oxide showed significant potential in improving combustion and lowering harmful emissions. The paper also examines environmental and health impacts associated with nano-additive usage and highlights challenges in large-scale application. Overall, this study supports the development of sustainable, cleaner fuel technologies by identifying effective nano-additives and preparation methods that optimize engine performance while minimizing environmental risks.