Optical investigation of the compression ignition combustion process with biofuels

Combustion characterization of waste cooking oil and canola oil based biodiesels under simulated engine conditions

This study aimed to evaluate the concentrations of sulfur dioxide (SO2) and nitrogen oxides (NOX) around the Qom (a province in Iran) combined cycle power plant in relation to seasonal variations and fuel type from December 2014 to May 2015. Passive sampling was used in three monitoring sites around the power plant to assess noncarcinogenic health risks associated with exposure to SO2 and NOX. Results showed the higher concentrations of NOX and SO2 in winter than in spring. The highest concentrations of NOX in winter (when power plants used gasoil) and spring (when power plants used gas fuel) were 52.70 ± 21.70/52.70 ± 13.20 and 22.10 ± 7.00 µg/m3. Similarly, the highest concentrations of SO2 in winter and spring were 5.00 ± 0.20 and 3.90 ± 0.70 µg/m3. There was a moderately significant correlation between NOx and SO2 concentrations when the power plant consumed gasoil (Spearman rho coefficient, 0.68, p < .05). A significant difference was observed between gas concentration and fuel type (p < .05). The hazard quotient values for SO2 exposure were below 1 for all age groups, whereas those for NOx were above 1 for infants and children. The hazard index for NOX was above 1, indicating an unacceptable risk to human health. Sobol' sensitivity analysis identified the inhalation rate and NOX concentration as the most significant factors determining the noncarcinogenic risks across age groups. In conclusion, the use of gasoil by power plants increases the emission of pollutants, thereby raising the health risks for residents in these regions, particularly vulnerable demographics like children. Therefore, prioritizing air quality management such as using cleaner fuels and emission control technologies in power plants as well as continuous air quality monitoring are of utmost importance.

The objectives of this research were to examine the effect of Sechium edule ethanolic extract to repair beta pancreas cells damage and tomeasure nitrogen oxide (NO) concentration in streptozotocin-induced rats. Type I diabetic rats were obtained by intraperioneally injected therats with multiple low dose streptozotocin (MLD-STZ) for 5 days. In this research, rats were assigned into 5 treatment groups: untreated rats ingroup 1 were considered as negative control, while MLD-STZ induced type 1 diabetic rats in group 2 were considered as positive control. Inanother 3 groups, type 1 diabetic rats were orally treated with three doses of Sechium edule ethanolic extract (14, 28, 42 mg/kg bw) respectivelyfor 7 consecutive days. Repairing of beta pancreas cells were analyzed descriptively whereas concentration of NO were analyzed using one wayANOVA and continued with LSD test (α= 0.01). The result showed that the administration of Sechium edule ethanolic extract significantlydecreased NO concentration (P&lt;0.01) up to 67.9 µM and repaired beta pancreas cells damage. Dose of 42 mg/kg bw of Sechium edule ethanolicextract is the effective dose for diabetic rat therapy. Key words: Sechium edule extract, diabetic mellitus, rat, beta pancreas cells

The chemical pathways for the production of secondary organic aerosols (SOA) are influenced by the concentration of nitrogen oxides (NOx), including the production of organonitrates (ON). Herein, a series of experiments conducted in an environmental chamber investigated the production and partitioning of total organonitrates from α-pinene photo-oxidation from <1 to 24 ppb NOx. Gas-phase and particle-phase organonitrates (gON and pON, respectively) were measured by laser-induced fluorescence (LIF). The composition of the particle phase and the particle mass concentration were simultaneously characterized by online aerosol mass spectrometry. The LIF and MS measurements of pON concentrations had a Pearson correlation coefficient of 0.91 from 0.3 to 1.1 μg m–3. For 1–6 ppb NOx, the yield of SOA particle mass concentration increased from 0.02 to 0.044 with NOx concentration. For >6 ppb NOx, the yield steadily dropped, reaching 0.034 at 24 ppb NOx. By comparison, the yield of pON steadily increased from 0.002 to 0.022 across the range of investigated NOx concentrations. The yield of gON likewise increased from 0.005 to 0.148. The gas-to-particle partitioning ratio (pON/(pON + gON)) depended strongly on the NOx concentration, changing from 0.27 to 0.13 as the NOx increased from <1 to 24 ppb. In the atmosphere, there is typically a cross-over point between clean and polluted conditions that strongly affects SOA production, and the results herein quantitatively identify 6 ppb NOx as that point for α-pinene photo-oxidation under these study conditions, including the production and partitioning of organonitrates. The trends in SOA yield and partitioning ratio as a function of NOx occur because of the changes in pON volatility.

Fossil fuels such as coal, petroleum and natural gas provide most of the energy needs of the world today. Coal and natural gas are used in their natural forms, but petroleum and other fossil fuels such as shale and bituminous sands require distillation and refinement to give usable fuels. These fuels exist in any of the following forms: solid, liquid and gas. The finite nature of global fossil fuel resources, high prices and most importantly, their damaging effect on the environment underscore the need to develop alternative fuels1 for many industrial systems that rely on fossil fuels. Increased use of renewable and alternative fuels can extend fossil fuel supplies and help resolve air pollution problems associated with the use of conventional fuels. This chapter reviews in detail some of the main alternative fuels used in cement production. It focuses on types of alternative fuels used, the environmental and socio-economic benefits of using alternative fuels, challenges associated with switching from conventional to alternative fuels, combustion characteristics of the alternative fuels concerned, and their effect on cement production and quality. The aim of this chapter is to provide empirical evaluation of alternative fuels. It offers an invaluable source of information for cement manufacturers that are interested in using alternative fuels. Researchers and students would also find this information valuable for their professional and academic development. Cement is considered one of the most important building materials around the world. Cement production is an energy-intensive process consuming thermal energy of the order of 3.3 GJ/tonne of clinker produced. Electrical energy consumption is about 90 – 120 kWh/tonne of cement (Giddings, et al, 2000; European Commission [EC] 2001). Historically, the primary fuel used in cement industry is coal. A wide range of other fuels such as gas, oil, liquid waste materials, solid waste materials and petroleum coke have all been successfully used as sources of energy for firing cement-making kilns, either on their own or in various combinations. The cement manufacturing industry is also under increasing pressure to reduce emissions. Cement manufacturing releases a lot of emissions such as carbon dioxide (CO2) and nitrogen oxide (NOx). It is estimated that 5 percent of global carbon dioxide emissions originate from cement production (Hendriks, et al, 1998). The use of alternative fuels in cement manufacturing, therefore do not only afford considerable energy cost reduction, but they also have significant ecological benefits of conserving non-renewable resources, the

The correlation between negative air ions (NAI) and nitrogen oxides (NOx) exhibits significant seasonal characteristics and is non-static. Previous studies have shown that NAI concentration is highly sensitive to meteorological factors, while NOx concentration is also affected by meteorological factors, resulting in potential differences in their correlation under different meteorological conditions. To deepen the understanding of this relationship, this study explored the impact of different meteorological factors on the correlation between NAI and NOx. The main conclusions are as follows: (1) The interaction between NAI and NOx in urban forests is regulated by meteorological factors; the higher the temperature, humidity, and solar radiation, the larger the correlation coefficient, and the stronger the negative correlation between the two; (2) Under synergistic meteorological conditions, NAI concentration is high and NOx concentration is moderate, which is suitable for outdoor activities: Condition 1 is temperature &gt; 20 °C, humidity 30–60%, air pressure &gt; 940 kPa, solar radiation 30–60 W·m−2, wind speed &lt; 1 m·s−1; Condition 2 is temperature &gt; 20 °C, humidity &gt; 60%, air pressure &gt; 940 kPa, solar radiation &gt; 60 W·m−2, wind speed &lt; 1 m·s−1 (based on NAI and NOx concentration data and health standards: NAI ≥ 1000 cm−3 is beneficial to health, and NOx ≤ 80 μg/m3 meets WHO limits); (3) Temperature, humidity, and air pressure have regulatory effects on the relationship between NAI and NOx, among which air pressure exerts positive regulation, while temperature and humidity exert negative regulation.

Diesel engine emissions for on-road, stationary and marine applications are regulated in the United States via standards set by the Environmental Protection Agency (EPA). A major component of diesel exhaust that is difficult to reduce is nitrogen oxides (NOx). Selective catalytic reduction (SCR) has been in use for many years for stationary applications, including external combustion boilers, and is promising for NOx abatement as a retrofit for mobile applications where diesel compression ignition engines are used. The research presented in this paper is the first phase of a program focused on the reduction of NOx by use of a stand-alone urea injection system, applicable to marine diesel engines typical of work boats (e.g., tugs). Most current urea SCR systems communicate with engine controls to predict NOx emissions based on signals such as torque and engine speed, however many marine engines in use still employ mechanical injection technology and lack electronic communication abilities. The system developed and discussed in this paper controls NOx emissions independentof engine operating parameters and measures NOx and exhaust flow using the following exhaust sensor inputs: absolute pressure, differential pressure, temperature, and NOx concentration. These sensor inputs were integrated into an independent controller and open loop architecture to estimate the necessary amount of urea needed, and the controller uses pulse width modulation (PWM) to power an automotive fuel injector for airless urea delivery. The system was tested in a transient test cell on a 350 hp engine certified at 4 g/bhp-hr of NOx, with a goal of reducing the engine out NOx levels by 50%. NOx reduction capabilities of 41-67% were shown on the non road transient cycle (NRTC) and ICOMIA E5 steady state cycles with system optimization during testing to minimize the dilute ammonia slip to cycle averages of 5-7 ppm. The goal of 50% reduction of NOx can be achieved dependent upon cycle. Further research with control optimization, urea distribution and possible use of oxidation catalysts is recommended to improve the NOx reduction capabilities while minimizing ammonia slip.

Nationwide, in 2020, 24 % of the U.S. population lived near high volume roadways, a source of nitrogen oxides (NOx) and nitrogen dioxide (NO2) emissions. This study synthesizes literature regarding NOx and NO2 gradients in the near-road environment to understand community exposures. We synthesize literature reporting measured NOx and NO2 concentrations at increasingly large distances from a single roadway and variables impacting those concentrations. Using the systematic literature search devised by U.S. EPA to develop Integrated Science Assessments, we identified publications that focused on near-road gradients of NO2 and NOx. The literature around near-road decay gradients were synthesized and summarized. Concentrations, distance to roadway, and other relevant information were extracted and analyzed using visual and regression methods to better understand the near-road decay gradient. Concentrations of NOx and NO2 decrease with increasing distance from major roadways, following nonlinear decay patterns. Analyzing these data revealed a decreasing power decay trendline. NOx and NO2 concentrations typically reduced approximately to background levels by 500 m, with the steepest decline occurring within 50 m from roadways. Concentrations increased with cooler temperatures and higher traffic. Gradients characterized by this review described how near-road populations are exposed to NOx and the variables that may better describe community exposure. This review provides a quantitative research synthesis of variables most impactful on near-road gradient exposures to NOx. Various meteorological and traffic variables were found to impact near-road gradients, though the gradient was driven by distance from the road.

Research aimed at finding new alternative fuels is becoming more and more urgent with each day, due to depletion of the world’s oil deposits and pollution of the atmosphere with toxic emissions of exhaust gases produced by the internal combustion engine. The article below describes the results of using alternative renewable fuels, such as methyl alcohol and methyl ether of rapeseed oil and their effects on the process of heat generation in diesel engine under various load conditions. The object of research is a 2F 10.5/12.0 engine with a dual fuel supply system installed on it. The obtained results showed that the optimal fixer advance angle of fuel injection is equal to 34° to the top dead centre for both types of fuel. The use of alternative fuels does not significantly affect the operational process. At the same time, it was noted that emissions of toxic agents, such as nitrogen oxides and soot, have significantly decreased.

Observation of the primary NO2 and NO oxidation near the trunk road in Tokyo

On-road vehicle emissions of carbon monoxide (CO), nitrogen oxides (NOx), and volatile organic compounds (VOCs) during 1995–2009 in the Atlanta Metropolitan Statistical Area were estimated using the Motor Vehicle Emission Simulator (MOVES) model and data from the National Emissions Inventories and the State of Georgia. Statistically significant downward trends (computed using the nonparametric Theil-Sen method) in annual on-road CO, NOx, and VOC emissions of 6.1%, 3.3%, and 6.0% per year, respectively, are noted during the 1995–2009 period despite an increase in total vehicle distance traveled. The CO and NOx emission trends are correlated with statistically significant downward trends in ambient air concentrations of CO and NOx in Atlanta ranging from 8.0% to 11.8% per year and from 5.8% to 8.7% per year, respectively, during similar time periods. Weather-adjusted summertime ozone concentrations in Atlanta exhibited a statistically significant declining trend of 2.3% per year during 2001–2009. Although this trend coexists with the declining trends in on-road NOx, VOC, and CO emissions, identifying the cause of the downward trend in ozone is complicated by reductions in multiple precursors from different source sectors.Implications:Large reductions in on-road vehicle emissions of CO and NOx in Atlanta from the late 1990s to 2009, despite an increase in total vehicle distance traveled, contributed to a significant improvement in air quality through decreases in ambient air concentrations of CO and NOx during this time period. Emissions reductions in motor vehicles and other source sectors resulted in these improvements and the observed declining trend in ozone concentrations over the past decade. Although these historical trends cannot be extrapolated to the future because pollutant concentration contributions due to on-road vehicle emissions will likely become an increasingly smaller fraction of the atmospheric total, they provide an indication of the benefits of past control measures.

Bone powder decorated TiO2 and ZnO nanoparticles: The first investigation of NOx degradation by solar light and visible light-driven photocatalyst

bustion, significant amounts of noxious substances are let off into the atmosphere, which produces an adverse effect on the environment. Further, one of the major sources of pollution are nitrogen oxides (NOx) consisting of the monoxide NO, the dioxide NO2, and the hemioxide N2O which are considered highly toxic. The concentration of nitrogen oxides has been going up constantly producing a greenhouse effect and reducing the ozone layer of the earth. Moreover, in the combustion products there is quite a lot of oxides of carbon, sulfur, benzopyrene, and other deleterious substances. Consequently, purification of combustion products from nitrogen and carbon oxides poses a serious technological problem. However, such purification is associated either with catching of gaseous emissions or with their conversion into useful or virtually harmless compounds. The methods employed in the industry for purification of gaseous emissions are based on absorption, adsorption, condensation, separation by a membrane, thermal combustion, chemical conversion of impurities into nontoxic compounds, biochemical purification, and catalysis. At present, catalysis is one of the promising and inexpensive methods of purification of combustion products. Its major advantages vis-a-vis other methods are high efficiency, low cost, and absence of harmful secondary phenomena. Catalytic reactions may be depicted as follows:

Driven by energy transition in the maritime industry, alternative fuels are considered one of the main energy solutions to meeting the demand forecast and achieving Greenhouse Gas (GHG) goals set by the International Maritime Organization (IMO). Zero/low-carbon fuels include methanol, ammonia, bio-fuel, hydrogen, etc. However, in contrast to traditional fuels, alternative fuels contain highly flammable (e.g., methanol) or toxic (e.g., ammonia) chemicals, posing safety concerns that need to be addressed in a structured manner. This paper presents several case studies using a fault tree analysis tool to improve the safety of zero-carbon fueled ships. INTRODUCTION Classification societies are at the frontier of setting the stage for alternative fuel propulsion systems. There is increased progress made by IMO in developing guidelines for ships using zero-carbon fuels. Design on the first ammonia internal combustion engine has been under significant development, whereas methanol engines have evolved further in the reliability journey. Safety is the driver for pursuit of the reliability journey involving new technologies, such as alternative fuels to responsibly minimize safety exposure and reduce GHG. Methanol engines have been in service for almost 10 years, and they have cleaner burning properties enabling reduced exhaust emissions such as sulfur oxides (SOx) and particulate matter (PM) and emit less nitrogen oxides (NOx) than conventional oil fuels. However, as a safety concern, in the open air, methanol burns with a flame that is nearly invisible in daylight with no smoke. Methanol as a marine fuel has been discussed in the ABS publication, Methanol bunkering: technical and operational advisory (ABS, 2024) Although ammonia is a well-established product with extensive land-based understanding and transportation history by Liquefied Petroleum Gas (LPG) carriers/cargo, its use as a marine fuel has not been demonstrated on a commercial scale. Technology providers such as engine, fuel supply system, and fuel treatment system vendors are currently working together to develop systems and equipment that can safely handle ammonia fuel. From the relevant ammonia hazards, toxicity is the most critical when compared with other conventional and alternative fuels. Ammonia as a marine fuel has been discussed in the ABS publication, Ammonia bunkering: technical and operational advisory (ABS, 2024).

This study was compiled from the results of various researches performed on using diethyl ether as a fuel or fuel additive in diesel engines. Three different techniques are used, the reduction of the harmful exhaust emissions of diesel engines. The first technique for the reduction of harmful emissions has improved the combustion by modification of engine design and fuel injection system, but this process is expensive and time-consuming. The second technique is the use of various exhaust gas devices like catalytic converter and diesel particulate filter. However, the use of these devices affects negatively diesel engine performance. The final technique to reduce emissions and also improve diesel engine performance is the use of various alternative fuels or fuel additives. The major pollutants of diesel engines are nitrogen oxides and particulate matter. It is very difficult to reduce nitrogen oxides and particulate matter emissions simultaneously in practice. Most researches declare that the best way to reduce these emissions is the use of various alternative fuels i.e. natural gas, biogas, biodiesel, or the use of fuel additives with these alternative fuels or conventional diesel fuel. Therefore, it is very important that the results of various studies on alternative fuels or fuel additives are evaluated together for practice applications. Especially, this study focuses on the use of diethyl ether in diesel engines as fuel or fuel additive in various diesel engine fuels. This review study investigates the effects of diethyl ether on the fuel properties, injection, and combustion characteristics.