Reduction Of Carbon Monoxide Research Articles

In silico design of dual-doped nitrogenated graphene (C2N) employed in electrocatalytic reduction of carbon monoxide to ethylene

Electrocatalytic reduction of carbon monoxide (CO) to valuable multi-carbon chemicals is among the most promising methods to ensure a sustainable carbon cycle.

CRUDE PALM OIL GUM AS ADSORBENT TO REDUCE RESEARCH OCTANE NUMBER AND BOILING POINT OF BIOETHANOL FOR GASOHOL E-85

The mixture of bioethanol with gasoline (gasohol) as vehicle fuel can increase the research octane number (RON) to perfect combustion and reduce carbon monoxide pollution from exhaust gases. The difference in electronegativity polarity causes the two fuels to be incompatible. This study aims to produce a homogeneous and compatible mixture of gasoline (85%) and bioethanol (15%) after the addition of crude palm oil (CPO) gum using degumming and distillation methods. The RON index calculation and physical properties of gasohol E-85 showed that the existence of CPO gum in bioethanol reduced the boiling point from 78 °C to 69 °C and the RON from 120 to 109. FTIR results showed that gasohol E-85 contains phosphatides, hydrocarbons, carboxylic acids, and tocopherols characteristic of CPO gum. The DSC results obtained a melting point of 43.8 °C which indicated that the CPO gum had mixed with bioethanol in gasohol E-85. The GC results of gasohol-85 obtained seven peaks indicating the presence of butylated hydroxytoluene, 1,9-decadiene, 4,4,7,7-tetramethyl, n-hexadecanoic acid, hexadecanoic acid, 2-hydroxy-1-(hydroxyl methyl) ethyl ester, 1-(3-methyl-2-butenyl)-2-phenylcyclopropane, and 9,9-bis(1"-indazolyl) -thioxanthene.

In situ formed N-containing copper nanoparticles: a high-performance catalyst toward carbon monoxide electroreduction to multicarbon products with high faradaic efficiency and current density.

Developing efficient catalysts for electrochemical carbon monoxide reduction (ECOR) with high faradaic efficiency (FE) and current density is highly desirable. In this work, we demonstrate that the N-containing Cu nanoparticles formed in situ by the reconstruction of cuprous 7,7,8,8-tetracyanoquinodimethane possess high-performance ECOR ability. Impressively, the N-containing Cu nanoparticle catalyst presented the highest FE of 81.31% towards multicarbon products with a high commercial-grade partial current density of 162.62 mA cm-2, which is among the best of the reported Cu-based ECOR catalysts at -0.69 V versus the reversible hydrogen electrode. The retained ligand on the formed catalyst via the convenient in situ formation is crucial for the selectivity of multicarbon products. This work will arouse enthusiasm for the utilization of reconstruction features for designing ligand-containing catalysts with enhanced artificial carbon fixation ability.

Medium-term Air Quality Benchmarking for Ecosystem Monitoring and Sustainability Planning: Case Study Dallas County (U.S.A.) 2015 to 2020

Medium-term air quality assessment, benchmarking it to recent past data can usefully complement short-term air quality index data for monitoring purposes. By using daily and monthly averaged data, medium-term air quality benchmarking provides a distinctive perspective with which to monitor air quality for sustainability planning and ecosystem perspectives. By normalizing the data for individual air pollutants to a standard scale they can be more easily integrated to generate a daily combined local area benchmark (CLAB). The objectives of the study are to demonstrate that medium-term air quality benchmarking can be tailored to reflect local conditions by selecting the most relevant pollutants to incorporate in the CLAB indicator. Such a benchmark can provide an overall air quality assessment for areas of interest. A case study is presented for Dallas County (U.S.A.) applying the proposed method by benchmarking 2020 data for air pollutants to their trends established for 2015 to 2019. Six air pollutants considered are: ozone, carbon monoxide, nitrogen dioxide, sulfur dioxide, benzene and particulate matter less than 2.5 micrometres. These pollutants are assessed individually and in terms of CLAB, and their 2020 variations for Dallas County compared to daily trends established for years 2015 to 2019. Reductions in benzene and carbon monoxide during much of 2020 are clearly discernible compared to preceding years. The CLAB indicator shows clear seasonal trends for air quality for 2015 to 2019 with high pollution in winter and spring compared to other seasons that is strongly influenced by climatic variations with some anthropogenic inputs. Conducting CLAB analysis on an ongoing basis, using a relevant nearpast time interval for benchmarking that covers several years, can reveal useful monthly, seasonal and annual trends in overall air quality. This type of medium-term, benchmarked air quality data analysis is well suited for ecosystem monitoring.

Cover Feature: The Conversion of Carbon Monoxide and Carbon Dioxide by Nitrogenases (ChemBioChem 8/2022)

The three nitrogenase isoenzymes: The molybdenum (Mo) nitrogenase, the vanadium (V) nitrogenase and the iron (Fe)-only nitrogenase, here depicted as superheroes, have a unique spectrum of activities for the reduction of molecular nitrogen (N2), carbon monoxide (CO) and carbon dioxide (CO2). The cover feature (created by Ehmad Chehrghani Bozcheloe) summarizes this minireview: the Mo nitrogenase has the highest activity for the reduction of molecular nitrogen (N2), the V nitrogenase for the reduction of CO and the Fe-only nitrogenase for the reduction of CO2. More information can be found in the Minireview by N. N. Oehlmann and Dr. J. G. Rebelein.

Dynamics at Polarized Carbon Dioxide–Iron Oxyhydroxide Interfaces Unveil the Origin of Multicarbon Product Formation

Surface-sensitive ambient pressure X-ray photoelectron spectroscopy and near-edge X-ray absorption fine structure spectroscopy combined with an electrocatalytic reactivity study, multilength-scale electron microscopy, and theoretical modeling provide insights into the gas-phase selective reduction of carbon dioxide to isopropanol on a nitrogen-doped carbon-supported iron oxyhydroxide electrocatalyst. Dissolved atomic carbon forms at relevant potentials for carbon dioxide reduction from the reduction of carbon monoxide chemisorbed on the surface of the ferrihydrite-like phase. Theoretical modeling reveals that the ferrihydrite structure allows vicinal chemisorbed carbon monoxide in the appropriate geometrical arrangement for coupling. Based on our observations, we suggest a mechanism of three-carbon-atom product formation, which involves the intermediate formation of atomic carbon that undergoes hydrogenation in the presence of hydrogen cations upon cathodic polarization. This mechanism is effective only in the case of thin ferrihydrite-like nanostructures coordinated at the edge planes of the graphitic support, where nitrogen edge sites stabilize these species and lower the overpotential for the reaction. Larger ferrihydrite-like nanoparticles are ineffective for electron transport.

EFFECT OF NUMBER OF TRANSITION METAL CATALYST CELLS MANGANESE CATALYTIC CONVERTER ON EXHAUST BASIS EMISSION OUTPUT CARBON MONOXIDE MOTOR GASOLINE

The technology used to reduce air pollution is using a Catalytic Converter which is installed on the exhaust gas channel (muffler) of gasoline motorized vehicles. This Catalytic Converter serves to accelerate the oxidation of Hydrocarbon (HC) and Carbon Monoxide (CO) emissions, as well as to reduce Nitrogen Oxide (NOx). In this study it was designed in such a way on a laboratory scale by studying the manganese transition metal material as a supporting copper catalyst, to see the ability of the catalyst to reduce carbon monoxide exhaust emissions. This study aims first to examine the ability of the manganese transition metal catalyst as a support for copper (CuMn) and secondly to examine the effect of increasing the number of catalyst cells on exhaust emission output. The first research results obtained were that the Manganese Transition metal catalyst as a supporting Copper (CuMn) was able to reduce the output of Carbon Monoxide exhaust emissions. Second, the addition of the number of catalyst cells on the Copper (Cu) catalyst did not have a significant effect, while the addition of the number of catalyst cells on the Manganese Transition metal catalyst as a support for Copper, from 5 catalysts to 10 catalysts, was able to reduce the output of Carbon Monoxide exhaust gas more significantly. However, in the number of 15 catalyst cells, the reduction in exhaust emissions was not significant.

The Conversion of Carbon Monoxide and Carbon Dioxide by Nitrogenases.

Nitrogenases are the only known family of enzymes that catalyze the reduction of molecular nitrogen (N2) to ammonia (NH3). The N2 reduction drives biological nitrogen fixation and the global nitrogen cycle. Besides the conversion of N2, nitrogenases catalyze a whole range of other reductions, including the reduction of the small gaseous substrates carbon monoxide (CO) and carbon dioxide (CO2) to hydrocarbons. However, it remains an open question whether these ‘side reactivities’ play a role under environmental conditions. Nonetheless, these reactivities and particularly the formation of hydrocarbons have spurred the interest in nitrogenases for biotechnological applications. There are three different isozymes of nitrogenase: the molybdenum and the alternative vanadium and iron‐only nitrogenase. The isozymes differ in their metal content, structure, and substrate‐dependent activity, despite their homology. This minireview focuses on the conversion of CO and CO2 to methane and higher hydrocarbons and aims to specify the differences in activity between the three nitrogenase isozymes.

Gliding Arc Discharge for Emission Control in Swirl Fuel-lean Non-premixed Combustion

ABSTRACT A reverse vortex flow gliding arc discharge in a fuel-rich premixed mixture was applied to a high swirl fuel-lean global combustion to accelerate fuel oxidation. Both the discharge and flame were generated in natural gas and air. To evaluate the role of the gliding arc in the process, a gas analysis of the exhaust gas was performed in the same operational conditions with and without plasma. The chemical measurements show that the plasma reduces carbon monoxide and unburned hydrocarbons contents with a low impact on the NOx level. Furthermore, the comparison of the relative decrease of the hydrocarbon emissions shows that the hydrocarbons have different sensitivities to the plasma application.

Exhaust Emission Characteristics of a Three-Wheeler Auto Diesel Engine Fueled with Pongamia, Mahua and Jatropha Biodiesels

Background: In India, three-wheeler auto diesel engines are also known as autorickshaw, play a vital role in day to day transportation. On the other hand, it pumps huge amount of harmful exhaust emissions into the atmosphere. As per the study by European Union 1% of India’s over two billion tonnes of annual vehicular CO2 emissions are from autorickshaws. Objective: To address the issue of high exhaust emissions from diesel engine, this paper has proposed Pongamia (PME), Mahua (PME) and Jatropha (JME) biodiesels as an alternative fuel. Methods: Biodiesel is produced by transesterification process; exhaust emissions analysis is carried out on a single cylinder four stroke three-wheeler auto diesel engine at constant speed of 1500rpm. Diesel as a reference fuel and cent percent of PME, MME, and JME as an alternative fuel. Results: Exhaust emissions reveals that there is a maximum reduction of Unburnt Hydrocarbons (UHC), Carbon Monoxide (CO), NOx, Carbon Dioxide (CO2), and smoke compared to diesel fuel. At maximum load the NOx emission reduced by 18.41% for JME, 17.46% for MME and 7.61% for PME. Low levels of CO emissions are recorded for JME (66%) followed by MME (33%) and PME (22%). UHC were reduced by 85.75% for JME, MME and for PME 14.28% reduction is observed. Smoke emissions are also reduced for PME and MME by 18.84%, for JME 14.49%. Conclusion: It is observed that all the methyl esters exhibit significant reduction in harmful exhaust emissions compared to diesel fuel and jatropha biodiesel is noted as a better choice.

Utilizing Hydrogen Underpotential Deposition for Carbon Monoxide Reduction to Formaldehyde

Formaldehyde is an essential building block for hundreds of chemicals and a promising liquid organic hydrogen carrier (LOHC), yet its indirect energy-intensive synthesis process prohibits it from playing more significant role. Here we report a direct CO reduction to formaldehyde (CORTF) process that hybridizes thermal and electro-catalysis and utilizes hydrogen underpotential deposition property to overcome thermodynamic barrier and scaling relationship restriction. Using molybdenum phosphide as catalyst, formaldehyde can be produced with nearly 100% Faradaic efficiency in aqueous KOH solution, with its formation rate being one order of magnitude higher compared with state-of-the-art thermal catalysis approach. Simultaneous tuning of current density and reaction temperature leads to more selective and productive formaldehyde synthesis, confirming the effectiveness of “hybrid” approach. DFT calculations reveal that desorption of *H2CO intermediate likely serves as rate-limiting step, and the participation of H2O turns the reaction into thermodynamically favorable. Furthermore, a full-cell reaction set-up was demonstrated with CO hydrogenation to HCHO being achieved without any energy input, which shows the spontaneous potential of the reaction. Our study shows the advantage of hybridizing thermal and electro-catalysis in realizing thermodynamics and scaling relation confined reaction, which could serve as a new strategy in future reaction design.

Effect of injection system parameters on overall performance of a small diesel engine

AbstractLimited fuel capacity and pollution are major concerns in the automobile industry. The combustion, performance, and emission characteristics are important considering the engine's overall performance. In the present paper, an experimental investigation was carried out on a small diesel engine to analyze the effect of injection system parameters on all measurable characteristics. The conventional diesel engine injection system was retrofitted with a common rail diesel injection (CRDI) system. The injection system parameters such as injection pressure, start of pilot injection timing, the start of main injection timing, and quantity of fuel injection percentage during the pilot and the main injection period were considered in the study. With the use of the CRDI system, it was observed that mean effective pressure and cylinder pressure were increased compared to the conventional diesel engine. There was a decrease in the peak value of the HRR and RoPR curve and simultaneously an increase in the width of the curve. MGT inside the combustion cylinder was also decreased. The retrofitted CRDI system shows higher thermal efficiency with good fuel economy as well as found a considerable reduction in carbon monoxide (CO) and smoke percentage. Overall, the considered injection system parameters deliver a significant improvement to the overall attributes of the small diesel engine.

Glycerol Oxidation Pairs with Carbon Monoxide Reduction for Low-Voltage Generation of C2 and C3 Product Streams

Glycerol Oxidation Pairs with Carbon Monoxide Reduction for Low-Voltage Generation of C₂ and C₃ Product Streams

Efficient electrochemical reduction of CO to C2 products on the transition metal and boron co-doped black phosphorene

The synthesis of high-value multi-carbon products through the electrochemical reduction of carbon monoxide (COER) is one of the promising avenues for carbon utilization and energy storage, in which searching for efficient electrocatalysts that exhibit moderate CO intermediate binding strength and low kinetic barrier for C-C coupling is a key issue. Herein, by means of comprehensive density functional theory (DFT) computations, we theoretically designed three synergistic coupling catalysts by co-doping transition metal (TM = Fe, Co and Ni) and boron (B) into the two-dimensional black phosphorene (BP), namely TM-B@BP for COER to C2 products. DFT computations and ab initio molecular dynamics simulations reveal the good stability and high feasibility of these proposed TM-B@BP catalysts for practical applications and future experimental synthesis. More interestingly, high-value ethylene (C2H4), ethane (C2H6) and ethanol (C2H5OH) products can be obtained on these three designed electrocatalysts with ultra-small limiting potentials (−0.20∼−0.41 V) and low kinetic energy barriers of C-C coupling (0.52∼0.91 eV). Meanwhile, the competitive one-carbon (C1) products and hydrogen evolution reaction can also be effectively suppressed. The promising activity and selectivity of these three designed electrocatalysts render them ideal candidates for CO electroreduction, thus providing a cost-effective opportunity to achieve a sustainable production of high value C2 chemicals and fuels.

Biogeochemical Gradients in a Serpentinization‐Influenced Aquifer: Implications for Gas Exchange Between the Subsurface and Atmosphere

AbstractSerpentinization involves the hydration and alteration of ultramafic rocks, which produces hydrogen (H2) and methane (CH4) and results in distinctive groundwater chemistries. As reacted fluids mix with recharging surface water, gradients in chemistry and microbiology develop in the subsurface. We present a comprehensive analysis of biogeochemical gradients in the water column of a serpentinite‐hosted well, CSW1.1, at the Coast Range Ophiolite Microbial Observatory (CROMO) in California, USA. Samples for geochemistry, 16S rRNA gene sequencing, and metagenomics were collected at four discrete depths from the top of the well corresponding to 100%, 50%, 15%, and 0% of atmospheric oxygen (O2) levels, and from the well base at 19.5 m depth. Gibbs energy calculations assessed the energy available for a suite of reactions coupled to O2, sulfate (SO42−), and nitrate (NO3−). Metagenomic data from the profile was used to construct metagenome assembled genomes (MAGs) to evaluate the completeness of biochemical pathways and compare the relative abundance of key diagnostic genes. Bioenergetic data point to the favorability of CH4 oxidation reactions despite little genetic evidence for this. Amplicon sequencing results highlight the abundance of key taxa affiliated with the genera Truepera, Serpentinomonas, and Dethiobacter. Although concentrations of NO3− and H2 are low, genes for NO3− reduction and oxidation of H2 and carbon monoxide (CO) were found in high abundance. Conceptual modeling results demonstrate the net depletion of H2 and CO in the groundwater, the consumption of CO2 and O2, and the potential for CH4 emission into the atmosphere at this terrestrial site of serpentinization.

Effect of Injection System Parameters on Performance and Emission Characteristics of a Small Single Cylinder Diesel Engine

Limited fossil fuel reservoir capacity and pollution caused by them is the big problem in front of researchers. In the present paper, an attempt was made to find a solution to the same. The conventional fuel injection system was retrofitted with a simple version of the common rail direct injection system for the small diesel engine. Further, the effect of injection system parameters was observed on the performance and emission characteristics of the retrofitted common rail direct injection diesel engine. The parameters such as injection pressure, the start of pilot injection timing, the start of main injection timing and quantity of percentage fuel injection during the pilot and main injection period were considered for experimental investigation. It was observed that all the evaluated parameters were found vital for improving the engine’s performance and emission characteristics. The retrofitted common rail direct injection system shows an average 7% rise in brake thermal efficiency with economic, specific fuel consumption. At the same time, much more reduction in hydrocarbon, carbon monoxide and smoke opacity with a penalty of a slight increase in nitrogen oxides.

An Overview on the Conversion of Forest Biomass into Bioenergy

Biomass plays a crucial role in mitigating the concerns associated with increasing fossil fuel combustion. Among various types of biomass, forest biomass has attracted considerable attention given its abundance and variations. In this work, an overview is presented on different pathways available to convert forest biomass into bioenergy. Direct use of forest biomass could reduce carbon dioxide emissions associated with conventional energy production systems. However, there are certain drawbacks to the direct use of forest biomass, such as low energy conversion rate and soot emissions and residues. Also, lack of continuous access to biomass is a severe concern in the long-term sustainability of direct electricity generation by forest biomass. To solve this problem, co-combustion with coal, as well as pelletizing of biomass, are recommended. The co-combustion of forest biomass and coal could reduce carbon monoxide, nitrogen oxides, and sulfide emissions of the process. Forest biomass can also be converted into various liquid and gaseous biofuels through biochemical and thermochemical processes, which are reviewed and discussed herein. Despite the favorable features of forest biomass conversion processes to bioenergy, their long-term sustainability should be more extensively scrutinized by future studies using advanced sustainability assessment tools such as life cycle assessment, exergy, etc.

Study on energy saving and environmental protection generator with hydrogen-oxygen-gasoline compound fuel.

The generator is the most popular mobile power device and backup power device in the world. It is very important for human life. Therefore, it is important to develop more efficient combustion technology in order to save energy and reduce air pollution. In this paper, a novel technology of hydrogen and oxygen compound gasoline fuel is developed. Hydrogen and oxygen gases are produced from an electrolytic cell and then mixed with the intake gasoline and air. The compound fuel is sucked into the engine combustion chamber. The hydrogen and oxygen gases can be produced immediately without any storage device of hydrogen. The experimental results show that this technology can increase the power generation and decrease emission pollution due to promoting combustion efficiency. In addition, the spark plug seat temperature increases due to higher heat value of hydrogen. This technique can reduce carbon monoxide and HC, but increase carbon dioxide. The research and development of this technique can achieve the goals of energy saving, emission reduction, relative safety, easy refitting and low refitting expense. Moreover, this research possesses academic innovation and industrial application.

One-Dimensional Analysis of Double Annular Combustor for Reducing Harmful Emissions

The number of aircraft flights worldwide has increased steadily since the introduction of air transportation to the public. Accordingly, environmental issues caused by the exhaust gases of aircraft engines have emerged. In particular, international organizations have crafted emission regulations since gases exhausted during takeoff and landing have been identified as the direct cause of air pollution near airports. Nitrogen oxides (NOx) produced at high combustion temperatures and carbon monoxide (CO) due to incomplete combustion affect the performance of the combustion chamber. Therefore, annular combustors comprising two annular zones have been developed to reduce the emissions of these two substances, which occur under different conditions. Parameters that should be considered when modifying a conventional single annular (SAC) to a double annular combustor (DAC) are discussed herein. In this paper, an optimization algorithm for obtaining the main design parameters of the DAC is presented to minimize NOx and CO emissions and an operation solution for reducing carbon monoxide emission is identified. A thermodynamic model of a high-bypass turbofan engine (PS-90A) is used to establish the inlet and outlet conditions of the combustor. Analysis results show that NOx emissions can be effectively reduced by adjusting the design parameters and CO emissions can be significantly decreased by partially turning off the fuel supply based on the engine cycle.

The Effect of Installing Modified Copper in Muffler to Reduce CO Levels in Vehicle Exhaust

This study aims to determine the effectiveness of modified copper to reduce carbon monoxide (CO) levels. Copper in the form of a plate shaped like a honeycomb and altered with activated carbon (SiO) and ZSM-5. The test uses a four-stroke 125 CC two-wheeled motor vehicle, fuel using Petalite, gasohol E5, gasohol E10, gasohol E15. The test carried out is the emission test of the effect of fuel variations and modified copper. The use of petalite fuel, variations of honeycomb copper + activated carbon (SiO-C) + ZSM-5 is more effective because it can reduce CO levels the most, which is 3.66% CO at 9000 rpm engine speed. For E5 fuel, the use of a honeycomb-shaped copper exhaust + Titan dioxide (TiO2) + Activated carbon (SiO-C) + ZSM-5 reduces CO levels by 3.42% CO at 9000 rpm engine speed. On the other hand, E10 fuel reduces CO levels by 1.35% CO when using exhaust with honeycomb copper+ TiO2 + SiO-C +ZSM-5.