Reduction In Carbon Monoxide Emissions Research Articles

Graphene-enhanced sustainable fuel from Calophyllum inophyllum for premixed charge compression ignition engines: Advancing circular economy and emission reduction

This study investigates the impact of modifying a conventional compression ignition (CI) engine by inducting pentanol in inlet manifold and injecting graphene-blended tamanu biodiesel into the cylinder. These modifications significantly enhance ignition quality and expand operational capabilities within the premixed charge compression ignition (PCCI) engine. The use of graphene-enhanced biodiesel in PCCI mode demonstrates potential for improved combustion efficiency and emission reduction. Dispersed graphene nanoparticles in tamanu biodiesel notably improve brake thermal efficiency due to their increased surface area, which enhances fuel-air mixing. Graphene-suspended biodiesel at a concentration of 100 ppm in PCCI mode results in an 11.5 % peak pressure rise and an 8.4 % rise in heat release rate with respect to pure biodiesel in CI mode. This nano-suspension biodiesel also shows significant thermal efficiency improvements, with an 8.20 % increase and a 22.08 % reduction in fuel consumption with respect to neat biodiesel in CI mode. The combination of pentanol and graphene-blended tamanu biodiesel improves combustion quality, yielding a 13 % reduction in carbon monoxide emissions, a 34.67 % reduction in hydrocarbon emissions, a notable 65.84 % lower in nitrogen oxide, and a 33.91 % reduction in smoke with respect to neat tamanu biodiesel in CI mode of operation.

Experimental investigation of emissions from a single-cylinder diesel engine using methanol–diesel blends

This study examines the effects of methanol–diesel blends on the emissions of a diesel engine, concentrating on carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides (NOx), hydrocarbons (HCs), and particulate matter (PM). Using a single-cylinder four-stroke diesel engine at varying torque settings (2 N m–6 N m), significant reductions in CO, CO2, HC, and PM emissions were observed with increasing methanol content. CO emissions reduced by up to 81.8%, CO2 by up to 64.2%, HC by up to 80.4%, and PM by up to 23.5% with the MD11 blend. NOx emissions initially increased but decreased by up to 20% at higher torques with the same blend. These results highlight the environmental benefits of methanol–diesel blends and the need for effective NOx reduction strategies.

Combination of high cetane diesel fuel and post injection mode in a diesel engine: A path towards lower exhaust emissions

The major objective of the presented work is to explore the effect of post injection (PI) strategy using neat diesel fuel (D100) blended with cetane number enhancer (CNE). The motive behind adding CNE in diesel fuel was to lower its self-ignition temperature and hence delay period subsequently. This can lead to more efficient combustion of post injected fuel which leads to lower incomplete combustion losses. The CNE used was Di-Tert-Butyl Peroxide (DTBP) which was blended with D100 in proportion of 1 % by volume. Initially experiments were conducted with D100 under various PI modes where variation of post injection timing (PIT) as well as post quantity (PQ) was considered. The experimental results showed that implementing PI resulted in lower smoke, unburned hydrocarbon (UHC), carbon monoxide (CO) and nitrogen oxides (NOx) emissions compared to single injection while affecting fuel consumption negatively. Then after similar experiments under various PI modes were repeated using blends of D100 and DTBP (D/DTBP) and results were compared with D100 case. It was found that addition of CNE in D100 resulted in more complete combustion of post fuel which further reduced CO and UHC emissions. The shorter delay period in case of D/DTBP blend compared to D100 case led to lower NOx emissions as well as higher smoke emissions. The obtained results revealed that PI mode with 3 mg PQ and 20° after top dead center (ATDC) PIT with D/DTBP blend offered 41.18 %, 17.55 %, 64 % and 62.5 % reduction in smoke, NOx, UHC and CO emissions respectively compared to single injection mode using D100 fuel.

Experimental study on energy and environmental impacts of alcohol-blended water emulsified cottonseed oil biodiesel in diesel engines

The increasing concern over environmental pollution and energy security has intensified the search for alternative fuels. This study explores the impact of 1-pentanol blends on the combustion performance and emission characteristics of water-emulsified Gossypium hirsutum (cottonseed) oil biodiesel in a compression ignition engine. Cottonseed oil was converted into biodiesel via transesterification, and its elemental, chemical, and physicochemical properties were thoroughly analyzed. A key contribution of this work is the formulation of a fuel blend comprising 30 % cottonseed oil biodiesel (COB) by volume mixed with diesel fuel, further emulsified with 10 % water by volume. The water-emulsified biodiesel was then enhanced with a 10 % volume concentration of 1-pentanol. The energy and environmental performance of these test fuels were evaluated in a single-cylinder compression ignition engine under various operating conditions. The study's findings reveal that the alcohol-blended, water-emulsified biodiesel significantly improves combustion efficiency and reduces emissions compared to conventional diesel fuel. Notably, the addition of 10 % 1-pentanol to the water-emulsified biodiesel led to a 14.3 % reduction in hydrocarbon emissions and a 12.8 % reduction in carbon monoxide emissions. Furthermore, there was a 3.2 % improvement in brake thermal efficiency and a 1.4 % decrease in specific fuel consumption. This research demonstrates that blending alcohol with water-emulsified biodiesel not only enhances combustion efficiency but also offers a promising strategy for reducing the environmental impact of diesel engines and potentially lowering fossil fuel dependence by 50 %.

Exergetic investigation of the influence of injector location in HCCI engines utilizing DEE as pilot fuel and biogas as primary fuel

To address the global demand for sustainable energy, integrating biogas into internal combustion engines is becoming more important. Homogeneous Charge Compression Ignition (HCCI) engines, known for high efficiency and low emissions, offer a promising solution. This study investigates the optimal injector location for using biogas in HCCI engines, with diethyl ether (DEE) as the pilot fuel, evaluating three positions: (i) at the port, (ii) 6 cm away (Manifold 1), and (iii) 10 cm away (Manifold 2). Through experiments and simulations, the impact of injector location on engine performance is analyzed across various parameters, including methane fractions, engine loads, and exhaust gas compositions. Results show that port injection achieves the highest first law and exergy efficiencies but increases emissions of hydrocarbons (HC), carbon monoxide (CO), and smoke. At 15 Nm load, Manifold 1 shows a 27.34 % reduction in exergy efficiency compared to port injection, while Manifold 2 exhibits an 18.49 % decrease at higher loads. Despite lower efficiencies, Manifold 1 effectively reduces harmful emissions. The study also considers exergo-economic and sustainability aspects, highlighting that while port injection is optimal for efficiency, Manifold 1 excels in minimizing HC and CO emissions, with a 50 % reduction in HC and 71.43 % reduction in CO emissions at 15 Nm load compared to port injection. Manifold 2 achieves the lowest smoke emissions across all loads. This investigation provides crucial insights into optimizing HCCI engines for biogas utilization, emphasizing injector location, fuel composition, and operating parameters to enhance performance and reduce environmental impact.

Pengaruh Modifikasi Permukaan Piston terhadap Emisi Gas Buang Motor Bakar Kapasitas 100 cc

Technological advances in motorized transportation are progressing rapidly, making motorized vehicles the main mode of transportation. The increasing number of motorized vehicles in society results in a significant increase in exhaust emissions. Combustion in vehicle engines is not always perfect, producing exhaust gases containing compounds harmful to human health, such as carbon monoxide (CO), hydrocarbons (HC), carbon dioxide (CO2), and nitrogen oxides (NOx). This study investigates the effect of variations in piston dome shape on exhaust emissions in a 100cc internal combustion engine using RON 90 fuel. The goal is to find the optimal compression ratio to produce cleaner exhaust emissions. The research data are presented in tabular form and analyzed using one-way ANOVA and graphs. The results showed a significant reduction in CO and HC emissions at all engine speeds (1000, 2000, 4000, and 5000 rpm) with variations in piston dome shape. The reduction in CO emissions ranged from 55.07% to 85.73%, while the reduction in HC emissions ranged from 54.14% to 86.10%. These results suggest that variations in piston dome shape can be an effective solution to minimize harmful exhaust emissions in internal combustion 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.

An Energy, and Emission Assessment of Diesel Engines Powered with Shorea Robusta Biodiesel and Blends

The present investigation examines the exergy, energy, and pollutants of a diesel-powered engine fuelled with a blend of Shorea Robusta Biodiesel (SRB) and normal diesel. The impact of engine power, speed, and fuel mix on emissions and operating characteristics are investigated. The use of blended fuels including SRB reduces a number of performance metrics, including BTE, exergy efficiency, and the sustainability index. Furthermore, CO (carbon monoxide), smoke, and HC (hydrocarbon) emissions are reduced when compared to utilising pure diesel fuel. SRB20 has the lowest HC emissions among the mixes SRB. At an engine speed of 1500 rpm and a power output of 5.5kW, SRB10, SRB20, and SRB30 blends lower HC emissions by 8.92%, 10.71%, and 7.14%, respectively. Similarly, when compared to conventional diesel fuel, SRB10, SRB20, and SRB30 blends reduce CO emissions by 1.25%, 5%, and 6.25%, respectively.

Butanol and selective catalytic reduction of gaseous emissions in a heavy-duty diesel engine

The impact of renewable fuels and their blends on vehicle exhaust emissions remains of high interest. In this study, we investigate the effect of butanol on the conversion efficiency of a Selective Catalytic Reduction (SCR) system installed on a commercial Euro V heavy-duty diesel engine (HDDE). Exhaust emissions were measured upstream and downstream of the SCR during dynamometer tests using diesel fuel and various butanol-diesel blends (5/95 %v, 10/90 %v, and 20/80 %v). Steady-state tests according to the World Harmonized Stationary Cycle (WHSC) on an engine bench were conducted including measurements of nitrogen oxides (NOX), total hydrocarbons (THC), and carbon monoxide (CO) emissions utilizing a portable emission measurement system (PEMS). The results showed a reduction in exhaust gas temperature (EGT) of around 4 % for a butanol content of 20 %. The use of butanol increased conversion efficiency of the SCR system by 4 % compared to diesel. The maximum SCR system conversion rate of around 96 % was obtained with a butanol content of 10 %. For all fuels, NOX conversion decreased at high engine loads (above 400 °C), while, as expected, was zero at low engine loads (below 200 °C). Reductions in CO and THC emissions were observed downstream of the SCR system. In general, this study shows that an SCR originally designed for a Euro V diesel engine can be equally effective when the engine is running on a partial blend of butanol.

Effect of Gadolinium Content on the Microstructures and Corrosion Properties of Mg-4Zn-3Gd Alloy

Lightweight metallic alloys in the transport sector are the essential choice to reduce carbon monoxide emissions. Magnesium (Mg) can serve this purpose appreciably because it has a low density compared to other metallic metals and a high strength in a small portion of metals. The reason behind this is having very low weight. Notwithstanding the alloys exhibit high susceptibility to corrosion especially galvanic corrosion, which impedes it from its various applications. The corrosion resistance of magnesium alloy depends largely on the surface film whether it can protect well and the corrosion due to galvanic effect between the second phase particles or microstructures and the magnesium matrix. Role of second phase particles eventually improves the corrosion property by enhancing its resistance to corrosion. Mg-4Zn being a promising alloy, 3 wt% Gd has been added further to investigate the corrosion resistant properties of Mg-4Zn-3Gd alloy. After preparing the alloys by casting method in induction furnace followed by homogenization at 410°C, the sample was hot rolled at 400°C. Preparation of the samples has been verified by EDS, XRF and XRD analysis. Corrosion study has been done for 1 hour, 24 hours and 72 hours. Microstructures have been taken for as cast, homogenized, and as rolled condition before corrosion test. The analysis shows a large difference in the grain size and phase distribution. Due to dynamic recrystallization during rolling hardness also shows differences compared to as cast and homogenized sample. The corrosion test is performed by weight loss test, electrochemical measurement, and immersion test. In the results, it has been seen an increase in corrosion rate at the initial stage, however it came to a constant rate after some time. After corrosion test, optical micrographs (OM) and scanning electron microstructures (SEM) images show typical morphology of corroded surface with some micro cracks. The presence of Gd in Mg-4Zn alloy enhanced the corrosion performance when it is done for longer time.

Study on the effect of wet scrubbing technique on emissions in a dual fuel engine operating with diesel and hydrogen.

Reducing emissions from internal combustion (IC) engines is a crucial goal, encompassing nitrogen oxide (NO), hydrocarbon (HC), carbon monoxide (CO), and smoke. To enhance both performance and emissions, contemporary IC engines have turned to alternative gases such as hydrogen (H2) and exhaust after-treatment systems. A promising method to effectively decrease exhaust emissions entails the application of the scrubber technique as an exhaust gas after-treatment. This study's objective is to explore two avenues for curtailing exhaust emissions. The first involves substituting traditional fuels in IC engines with hydrogen gas (H2) at a flow rate of 6 LPM. The second entails integrating a liquid chemical solution into the scrubber technique. Notably, the utilization of KMnO4 solutions exhibits an appreciable reduction in NO and CO emissions compared to solutions containing NaOH. The experimental process included two aspects: investigating hydrogen fuel (H2) as an alternative fuel for IC engines and incorporating a scrubber technique using both KMnO4 and NaOH solutions. These experiments were conducted using a single-cylinder engine with a power output of 5.2 kW, cooled by water. The engine underwent tests under various load conditions, spanning from minimal to maximal loads. The findings revealed that employing KMnO4 solutions within the scrubber technique led to reductions of 25% and 40% in NO and CO emissions, respectively, in contrast to the utilization of NaOH solutions. Similarly, introduction hydrogen gas also has a significant effect on emission reduction.

Performance, evaluation and gas emission of diesel and distilled biodiesel blends in IC engine

The greenhouse gas emissions caused by burning fossil fuels are a global issue. Nowadays, biodiesel has been shown to be a good alternative to substitute totally or partially diesel to minimize GHG emissions formed during the combustion of diesel fuel in engines. This research investigates the usability of distilled biodiesel–diesel blends in a diesel engine. The distilled biodiesel was produced from soybean and coconut oil, and each fraction’s composition was characterized by gas chromatography–mass spectrometer. The soybean biodiesel light fraction was shown to be rich in compounds with up to 17 carbons, while the coconut biodiesel light fraction contained compounds with up to 13 carbons. All blends evaluated were within the density range of commercial diesel (0.82 to 0.85 g.cm−3). The consumption and emissions experiments were performed on a 1-cylinder, 4-stroke diesel engine at various loads to evaluate the influence of distilled biodiesel from soybean and coconut oil. For all blends, adding distilled biodiesel, both from soybean and coconut oil, increased the brake thermal efficiency up to 56.08% and reduced the specific fuel consumption up to 18.33% compared to diesel fuel. In addition, all distilled biodiesel–diesel blends reduced carbon monoxide emissions by up to 30%.

Predicting the effects of direct-injected fuels co-powered by high-CO2 biogas on RCCI engine emissions using kinetic mechanisms and multi-objective optimization

High inert gas content in biogas resulted in poor burning and emissions attributes, though scarcely investigated in reactivity controlled compression ignition (RCCI). Established kinetic mechanisms were combined with multi-objective optimization to investigate, predict, and analyze emissions occurrence and trade-offs for reduced environmental impacts. The work examined the impact of direct-injected high reactivity fuels (HRF) and port-injected Biogas at various inert gas (carbon dioxide, CO2) rates (25 – 45% vol), biogas fractions (40 – 70%), speeds (1600 – 2000 rpm), and loads (4.5 – 6.5 bar IMEP) on emissions of RCCI engine, experimentally. The findings revealed that while engine speeds greatly decreased CO (carbon monoxide) and NOx (nitrate oxide) emissions with rising unburned hydrocarbon (UHC) regardless of HRF employed, higher engine load significantly reduced UHC emissions. Diesel-biogas reduces NOx emissions and performs better in reducing CO and UHC emissions at lower speeds than B5-biogas, except in low-level loads. Although increasing CO2 impact led to a reduction in UHC and CO emissions, the biogas proportion was the most significant variable. The main factor influencing increased NOx emissions was engine load, which is inversely correlated with reduced NOx and increased particulate emissions owing to high CO2 content and biogas proportion. The premixed mode's optimisation outcome confirms the trade-off reduction at 5.5 bar IMEP, 35.586% CO2, and 50% fraction. As a result, running the RCCI engine with direct-injected diesel co-powered in equal proportion with high-CO2 biogas cuts the emissions trade-off dramatically, limiting the environmental repercussions of the emissions.

Spatial and temporal analysis of influential factors on motor vehicle carbon monoxide emissions in China considering emissions trading scheme.

The number of cars is increasing every year and the environmental aspects of transport are becoming a hot topic. The spatial and temporal patterns of motor vehicle carbon monoxide (CO) emissions are still unclear due to the unbalanced economic development and heterogeneous geographic conditions of China. With the objective of realizing a reduction in motor vehicle CO emissions, his study explores the transport carbon emission reduction pathways of China from motor vehicle CO emission. Firstly, the entropy method is adopted to comprehensively evaluate the CO emissions from motor vehicles in each province; secondly, the development of a Geographically and Temporally Weighted Regression (GTWR) model facilitates the examination of the spatiotemporal dynamics pertaining to the influencing factors of motor vehicle CO emissions within each province.; finally, the characteristics of motor vehicle CO emissions in ETS pilot areas and non-ETS pilot areas are compared. The results show that: (1) After the completion of the six ETS pilot areas in 2011, the CO emission from motor vehicles is reduced by 18% compared with 2010.(2)The entropy method shows that the largest CO emissions from motor vehicles are from Beijing, Shanghai, Guangdong and other provinces with high economic levels.(3) The results of the GTWR model show that the positive effects of economic level, population size, road mileage intensity and motor vehicle intensity on motor vehicle CO emissions are decreasing year by year. The negative effect of metro line intensity on CO emission decreases year by year. This study can help decision makers to identify the high emission areas, understand the influencing factors, and formulate emission reduction measures to achieve the purpose of carbon emission reduction in transport.

Green Synthesis of CuO Nanoparticles from Blackberry Leaves Extract (Rubus fruticosus) and Experimental Research of Its Effects on Emissions Analysis for IC Engines

As an additive for diesel engines, copper oxide nanoparticles (CuONPs) are thought to offer a lot of promise. In this work, an experimental investigation was conducted to ascertain the impact on a diesel engine of adding copper oxide (CuO) particles made from a Rubus fruticosus leaf extract product using a novel green synthesis approach. The presence and morphology of the CuO were analyzed by different characterization studies. Subsequently, was investigated the effects of the addition of CuONPs at two concentrations (15 and 20 ppm) on diesel engine performance, brake‐specific fuel consumption (BSFC), carbon monoxide (CO), hydrocarbon (HC), nitrogen oxide (NOX), and smoke emissions. From the experimental outcomes, the D100 + 20 ppm CuO blend shows a significant reduction in CO, HC, and smoke emissions by 58.19%, 25.15%, and 26.67%, respectively, when compared with standard diesel. Also, it was found that the D100 + 20 ppm CuO blend showed better engine performance with enhanced combustion characteristics. The experimental results provided a reduction of around 1.10% in BSFC. This study demonstrates how changes in fuel composition through the addition of nanoparticles to commonly used diesel fuel can provide meaningful improvements in engine performance and emissions.

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

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

Southern Hemisphere atmospheric history of carbon monoxide over the late Holocene reconstructed from multiple Antarctic ice archives

Abstract. Carbon monoxide (CO) is a naturally occurring atmospheric trace gas, a regulated pollutant, and one of the main components determining the oxidative capacity of the atmosphere. Evaluating climate–chemistry models under different conditions than today and constraining past CO sources requires a reliable record of atmospheric CO mixing ratios ([CO]) that includes data since preindustrial times. Here, we report the first continuous record of atmospheric [CO] for Southern Hemisphere (SH) high latitudes over the past 3 millennia. Our continuous record is a composite of three high-resolution Antarctic ice core gas records and firn air measurements from seven Antarctic locations. The ice core gas [CO] records were measured by continuous flow analysis (CFA), using an optical feedback cavity-enhanced absorption spectrometer (OF-CEAS), achieving excellent external precision (2.8–8.8 ppb; 2σ) and consistently low blanks (ranging from 4.1±1.2 to 7.4±1.4 ppb), thus enabling paleo-atmospheric interpretations. Six new firn air [CO] Antarctic datasets collected between 1993 and 2016 CE at the DE08-2, DSSW19K, DSSW20K, South Pole, Aurora Basin North (ABN), and Lock-In sites (and one previously published firn CO dataset at Berkner) were used to reconstruct the atmospheric history of CO from ∼1897 CE, using inverse modeling that incorporates the influence of gas transport in firn. Excellent consistency was observed between the youngest ice core gas [CO] and the [CO] from the base of the firn and between the recent firn [CO] and atmospheric [CO] measurements at Mawson station (eastern Antarctica), yielding a consistent and contiguous record of CO across these different archives. Our Antarctic [CO] record is relatively stable from −835 to 1500 CE, with mixing ratios within a 30–45 ppb range (2σ). There is a ∼5 ppb decrease in [CO] to a minimum at around 1700 CE during the Little Ice Age. CO mixing ratios then increase over time to reach a maximum of ∼54 ppb by ∼1985 CE. Most of the industrial period [CO] growth occurred between about 1940 to 1985 CE, after which there was an overall [CO] decrease, as observed in Greenland firn air and later at atmospheric monitoring sites and attributed partly to reduced CO emissions from combustion sources. Our Antarctic ice core gas CO observations differ from previously published records in two key aspects. First, our mixing ratios are significantly lower than reported previously, suggesting that previous studies underestimated blank contributions. Second, our new CO record does not show a maximum in the late 1800s. The absence of a [CO] peak around the turn of the century argues against there being a peak in Southern Hemisphere biomass burning at this time, which is in agreement with (i) other paleofire proxies such as ethane or acetylene and (ii) conclusions reached by paleofire modeling. The combined ice core and firn air [CO] history, spanning −835 to 1992 CE, extended to the present by the Mawson atmospheric record, provides a useful benchmark for future atmospheric chemistry modeling studies.

Reduction of Carbon Monoxide Emissions into the Atmosphere When Burning Fuel Oil in Technological Thermal Power Plants

An effective method and device for additional heating of fuel oil used in the production of soda ash as fuel in soda drum dryers has been developed. It is concluded that the use of a high-frequency induction unit mounted on the fuel oil supply line in the thermal power equipment of soda ash drum dryers provides an increase in the temperature of fuel oil from 60 to 98 °С, a reduction in its specific consumption by 15.7 % and a reduction in carbon monoxide emissions into the atmosphere from 0.20 to 0.024 g /s.

A novel model of a hydrogen production in micro reactor: Conversion reaction of methane with water vapor and catalytic

This study presents a comprehensive investigation of a thermally integrated membrane micro reactor for efficient hydrogen production through the conversion of methane with water vapor. The reactor design incorporates a catalytic Au/ZnO system to enhance performance. The effects of key operational variables, including inlet gas flow rate, pressure, temperature, water-to-methane ratio, and membrane thickness, were examined. Optimal conditions were sought to maximize methane conversion, hydrogen yield, and minimize carbon monoxide production. As feed flow increases, methane conversion decreases due to reduced retention time in the reactor. This decrease is almost six times greater at 240 °C than at 270 °C. Higher water-to-methane ratios improved methane conversion and reduced hydrogen and carbon monoxide production. Shell pressure affected methane conversion, with higher pressures resulting in decreased rates and carbon monoxide levels. As shell airflow velocity increases, methane conversion rises about 0.96 %. Tube pressure influenced hydrogen passage through the membrane, causing decreased hydrogen output from the tube section and increased output from the shell section, while reducing carbon monoxide emissions. These findings contribute to the optimization of a thermally integrated membrane micro reactor for efficient hydrogen production through water vapor-methane conversion.

Methanol (M85) Port-Fuel-Injected Spark Ignition Motorcycle Engine Development—Part 2: Dynamic Performance, Transient Emissions, and Catalytic Converter Effectiveness

<div>Methanol is emerging as an alternate internal combustion engine fuel. It is getting attention in countries such as China and India as an emerging transport fuel. Using methanol in spark ignition engines is easier and more economical than in compression ignition engines via the blending approach. M85 (85% v/v methanol and 15% v/v gasoline) is one of the preferred blends with the highest methanol concentration. However, its physicochemical properties significantly differ from gasoline, leading to challenges in operating existing vehicles. This experimental study addresses the challenges such as cold-start operation and poor throttle response of M85-fueled motorcycle using a port fuel injection engine. In this study, M85-fueled motorcycle prototype is developed with superior performance, similar/better drivability, and lower emissions than a gasoline-fueled port-fuel-injected motorcycle. An open electronic control unit was installed using suitable wiring harness/sensors and actuators to control the engine. Then the motorcycle electronic control unit was calibrated for transient operations on a chassis dynamometer. The motorcycle was tested under road load simulation and wide-open throttle conditions on the chassis dynamometer to compare its performance with a baseline gasoline-fueled motorcycle. Evaluation parameters included power at wheels, maximum vehicle speed, and time-based and speed-based acceleration characteristics. Transient emissions were evaluated following the Indian driving cycle protocols. The effectiveness of the catalytic converter for M85 fueling was assessed by comparing various emissions upstream and downstream of the catalytic converter. M85-fueled motorcycle generated higher power at wheels and similar maximum speeds as baseline gasoline-fueled motorcycle. Fine-tuned M85-fueled motorcycle exhibited superior acceleration characteristics over baseline gasoline-fueled motorcycle, indicating that an appropriate tuning strategy could tackle the issue of “drivability.” M85-fueled motorcycle emitted lower carbon monoxide and hydrocarbon during the warm-up cycles in the Indian driving cycle protocol. The inherent fuel oxygen of M85 enhanced the carbon monoxide–carbon dioxide conversion, reducing carbon monoxide emissions in the engine exhaust. The existing catalytic converter was also suitable for M85 fueling since the hydrocarbon, nitric oxide, and carbon monoxide emissions were effectively reduced downstream of the catalytic converter in all test conditions.</div>