Carbon Burning Research Articles

Modeling and Simulation of Janus-like Nanoparticles Formation by Solid-Gas Exothermic Reactions

Theoretical model for the simulation of synthesis of Janus-like particles (JP) consisting two different phases using the Carbon Combustion Synthesis of Oxides (CCSO) is presented. The model includes the variation of sample initial porosity, carbon concentration and oxygen flow rate used to predict the formation of JP features. The two temperature (2T) combustion model of chemically active submicron-dispersed mixture of two phases including ferroelectric and ferromagnetic was implemented and assessed by using the experimentally estimated activation energy of 112±3.3 kJ/mol and combustion temperature. The experimental values allowed to account the thermal and concentration expansion effect along with the dispersion by the slip-jump simulation for high Knudsen numbers. The model predicted that the smaller initial porosity of the combustion media creates higher formation rate of Janus-like particles. The simulation of slippage and jumps of the gas temperature allowed the scale-bridging between macro- and micro- structures.

The most metal-rich asymptotic giant branch stars

ABSTRACT We present new stellar evolutionary sequences of very metal-rich stars evolved with the Monash Stellar Structure code and with mesa. The Monash models include masses of 1–8 M⊙ with metallicities Z = 0.04 to Z = 0.1 and are evolved from the main sequence to the thermally pulsing asymptotic giant branch (TP-AGB). These are the first Z = 0.1 AGB models in the literature. The mesa models include intermediate-mass models with Z = 0.06 to Z = 0.09 evolved to the onset of the TP phase. Third dredge-up only occurs in intermediate-mass models Z ≤ 0.08. Hot bottom burning shows a weaker dependence on metallicity, with the minimum mass increasing from 4.5 M⊙ for Z = 0.014 to ≈5.5 M⊙ for Z = 0.04, 6 M⊙ for 0.05 ≤ Z ≤ 0.07 and above 6.5 M⊙ for Z ≥ 0.08. The behaviour of the Z = 0.1 models is unusual; most do not experience He-shell instabilities owing to rapid mass-loss on the early part of the AGB. Turning off mass-loss produces He-shell instabilities, however thermal pulses are weak and result in no TDU. The minimum mass for carbon ignition is reduced from 8 M⊙ for Z = 0.04 to 7 M⊙ for Z = 0.1, which implies a reduction in the minimum mass for core-collapse supernovae. mesa models of similarly high metallicity (Z = 0.06–0.09) show the same lowering of the minimum mass for carbon ignition: carbon burning is detected in a 6 M⊙ model at the highest metallicity (Z = 0.09) and in all 7 M⊙ models with Z ≥ 0.06. This demonstrates robustness of the lowered carbon burning threshold across codes.

Effect of Selected Components on Combustion of Methane

Abstract Article discusses the effect of various gases on the combustion of methane in LGW 702 combustion engine intended for use in cogeneration unit. The measured results were evaluated for internal, performance and economic parameters of the combustion engine the ideal operating parameters can be set. The aim of the study was to assess the effect of combustible carbon monoxide and carbon dioxide and nitrogen on the parameters.

A study of white dwarf shock detonation and type Ia supernova explosion

Type Ia supernovae are not only sources of the elements of “life”, but also “standard candles” for measuring distances in the Universe. To describe the process, a hydrodynamic model of white dwarfs that takes into account the nuclear combustion of carbon is constructed. It is closed by a stellar equation of state and supplemented by a Poisson equation for the gravitational potential. The results of a mathematical simulation of a white dwarf shock detonation and subsequent explosion of a type Ia supernova are described. The computational experiments have shown that the dynamics of the shock detonation is determined by the explosion energy and the ignition point. A study of scalability and energy efficiency of the software implementation are also performed.'

Mathematical simulation of turbulent combustion of carbon in the problems of white dwarf mergers and explosions of the type Ia supernovae

Mathematical simulation of turbulent combustion of carbon in the problems of white dwarf mergers and explosions of the type Ia supernovae

CO2 reduction in a common rail direct injection engine using the combined effect of low carbon biofuels, hydrogen and a post combustion carbon capture system

ABSTRACT The transportation sector is a major emitter of carbon dioxide emissions. It is a known fact that carbon dioxide is the cause of global warming which has resulted in extreme weather conditions as well as climate change. In this study a combination of different methods of expediting the CO2 emission from a single cylinder common rail direct injection (CRDI) engine has been explored. The methods include use of low carbon content biofuels (lemon peel oil (LPO) and camphor oil (CMO), inducing hydrogen in the intake manifold and zeolite based after-treatment system. Initial engine operation with the low carbon content biofuel blends resulted in reduced smoke and CO2 emissions. Substitution of the blends with hydrogen further assisted in decrease in emission and improvement in engine efficiency. Later on in the exhaust pipe an after-treatment system containing zeolite was placed. The emissions were found to reduce even further and at full load condition the lowest CO2 (39.7% reduction) and smoke (49% reduction) emissions were observed with LPO blend and hydrogen induction. The NO emission with hydrogen induction increases for both the blends, however, it was seen that the zeolite based treatment system was effective in reducing the emission as well. As compared to baseline diesel, the maximum reduction in NO emission was 23% at full load with LPO blend, hydrogen induction and after-treatment system.

Metal Oxides as Soluble Nano Catalyst on Biodiesel: A Review

Nano particles of metal oxide developed as soluble nano additive in liquid fuels to improve fuel quality. One application of nano metal oxide particles is an additive to biodiesel. Biodiesel is an alternative fuel that can reduce dependence on fossil fuels. Pure biodiesel has a relatively lower calorific value compared to fossil fuels. Low calorific value results in increased brake specific fuel consumption. Moreover, biodiesel has a higher density and viscosity compared to fossil fuel. The content of carbon monoxide (CO), unburned hydrocarbons (HC) and nitrogen oxide (NOx) in exhaust gases with biodiesel is higher than fossil fuels. Metal oxide nanoparticles are added to biodiesel between 6 to 80 nm with concentrations about 50 to 500 ppm. Addition of metal oxide nanoparticles to biodiesel can improve brake thermal efficiency, reduce brake specific fuel consumption, carbon monoxide (CO), unburned hydrocarbons (HC), nitrogen oxide (NOx) and improve carbon dioxide (CO2) emission due to the catalytic effect of metal oxide nanoparticles. Metal oxide acts as an oxidation catalyst thereby reduce the carbon combustion activation temperature and thus enhances hydrocarbon oxidation, promoting complete combustion. Nanoparticles that are often used in various studies are nickel (II) oxide (NiO), cerium (IV) oxide (CeO2), titanium oxide (TiO2), zinc oxide (ZnO), aluminum oxide (Al2O3), and silicon dioxide (SiO2). This review paper describes the progress and development of nano metal oxide applications as additives for biodiesel, and the discussion in this paper is divided into 3 main topics, including the effects of nanoparticles on the properties of biodiesel, engine performance, and emission characteristics.

Investigation on combustion, gaseous pollutants emission and ash characteristics during co-combustion of semicoke and coal slime

Co-combustion of semicoke and coal slime is promising for their co-disposal. In this study, the co-combustion behaviors, interaction and gaseous pollutants emission of semicoke and coal slime were studied by thermogravimetric analyzer coupled with Fourier transform infrared spectrometer (TG-FTIR). The ash characteristics after co-combustion were also investigated. Results showed adding coal slime could improve the ignition and burnout performance of blends but lead to the declining comprehensive combustion index. Inhibitory effects were prominent at the early stage of co-combustion due to the heat competition while promoting effects existed in fixed carbon combustion. The ash accumulation suppressed co-combustion again at the burnout stage. Semicoke could reduce NO, NO2 and SO2 emission of blends but also cause serious slagging because of the high Ca content. Adding coal slime could prevent the generation of eutectics and thus decrease the ash slagging propensity of blends. The sulfur-retention reaction was more intense at coal slime blend ratio of 40%. Semicoke ash had higher Mn, Ni and Cu concentrations while coal slime ash has more Zn and Pb contents. With the increase of coal slime blend ratios, Mn, Ni and Cu in ash gradually decreased while Zn and Pb increased.

The Deposit Formation Mechanism in Coal-Fired Rotary Kiln for Iron Ore Pellet Production: A Review

The deposit-forming problem is one of the main bottlenecks restricting the yield and production benefit of iron ore pellets produced by coal-fired rotary kilns. In order to implement measures to ensure the efficient production of pellets by coal-fired rotary kilns, the mechanism and influencing factors on the deposit formation were reviewed. The pellet powder and coal ash come together to form the material base of the deposit. Meanwhile, the local reducing atmosphere caused by the continued combustion of residual carbon increases the FeO content, resulting in the formation of low-melting-point silicates. Moreover, alkali metal elements in coal ash can also promote liquid phase formation to cause serious deposit aggregation problems. During high-temperature roasting, the liquid phase corrodes the surface of the refractory brick to form the initial deposit, whereafter, it binds the pellet powder and coal ash from the material layer, which causes the deposit to accumulate continuously. The deposit formation of coal-fired rotary kilns is the result of interaction between many factors, which includes the quality of the green pellets, the composition of coal ash, the combustion efficiency of pulverized coal, roasting temperature, FeO content and alkali metal input. Finally, it is recommended that some measures to mitigate deposit formation can be adopted, such as increasing the compression strength of preheated pellets, choosing high-quality raw materials with low alkali metals, improving the combustion of pulverized coal.

Mathematical Simulation of Turbulent Combustion of Carbon in the Problems of White Dwarf Mergers and Explosions of Type Ia Supernovae

Mathematical Simulation of Turbulent Combustion of Carbon in the Problems of White Dwarf Mergers and Explosions of Type Ia Supernovae

Easy-to-Fabricate K₂Pd(SO₃)₂-Dyed Polyester Fabric with Highly Selective and Fast Response to Carbon Monoxide.

Carbon monoxide (CO) is an odorless, colorless, tasteless, extremely flammable, and highly toxic gas. It is produced when there is insufficient oxygen supply during the combustion of carbon to produce carbon dioxide (CO₂). CO is produced from operating engines, stoves, or furnaces. CO poisoning occurs when CO accumulates in the bloodstream and can result in severe tissue damage or even death. Many types of CO sensors have been reported, including electrochemical, semiconductor metal-oxide, catalytic combustion, thermal conductivity, and infrared absorption-type for the detection of CO. However, despite their excellent selectivity and sensitivity, issues such as complexity, power consumption, and calibration limit their applications. In this study, a fabricbased colorimetric CO sensor is proposed to address these issues. Potassium disulfitopalladate (II) (K₂Pd(SO₃)₂) is dyed on a polyester fabric as a sensing material for selective CO detection. The sensing characteristics and performance are investigated using optical instruments such as RGB sensor and spectrometer. The sensor shows immediate color change when exposed to CO at a concentration that is even lower than 20 ppm before 2 min. The fast response time of the sensor is attributed to its high porosity to react with CO. This easy-to-fabricate and cost-effective sensor can detect and prevent the leakage of CO simultaneously with high sensitivity and selectivity toward CO.

Study on the Physical, Chemical and Combustion Characteristics of Pyrolysis Semi-coke

ABSTRACT Combustion is an effective method for large-scale utilization of pyrolytic semi-coke (SC), a high order carbon-based solid fuel with low volatile content. The combustion characteristics of SC can be deeply understood through the study of physical and chemical properties. Taking SC as the research object and anthracite (YQ) with similar chemical composition as the control, the activation energy (E) of SC and YQ was calculated respectively by using model-free method and model method (16 typical mechanism functions). The pre-exponential factor (A), the change of enthalpy (ΔH), the change of entropy (ΔS), and the change of Gibbs free energy (ΔG) during the reaction were calculated. As a result, the pore inside of the particle is the main part of the pore structure of SC. The total specific surface area, pore-volume, and fractal dimension of SC are all larger than that of YQ. There is a lot of amorphous carbon in both SC and YQ, and the lattice spacing and graphitization degree of SC is smaller than that of YQ, but the average aromatic carbon lateral size and crystallite volume are much larger than that of YQ. The carbon in SC and YQ mainly exists in the form of aromatic carbon and aliphatic carbon, and the relative content of aromatic carbon in SC and YQ is basically the same. For the model method, the E of SC and YQ calculated by the three-dimensional diffusion (Spherical symmetric) mechanism function is the closest to the E obtained by the model-free method. Different from YQ, the main combustion stage of SC is composed of fixed carbon combustion and CaCO3 decomposition, and basically, no NH3 and HCN are generated. The volatile content of SC, the total specific surface area, and the pore volume in the pore are larger than that of YQ, which results in that the ignition temperature of SC is lower than that of YQ. The E and burn-out temperature of SC are higher than that of YQ due to the lower oxygen-containing functional group content, higher aromatic carbon content, fractal dimension and larger crystallite volume. Comprehensive physical, chemical, and combustion characteristics results show that using SC by combustion is more difficult than YQ.

The impact of organic pollutants from Indonesian peatland fires on the tropospheric and lower stratospheric composition

Abstract. The particularly strong dry season in Indonesia in 2015, caused by an exceptionally strong El Niño, led to severe peatland fires resulting in high volatile organic compound (VOC) biomass burning emissions. At the same time, the developing Asian monsoon anticyclone (ASMA) and the general upward transport in the Intertropical Convergence Zone (ITCZ) efficiently transported the resulting primary and secondary pollutants to the upper troposphere and lower stratosphere (UTLS). In this study, we assess the importance of these VOC emissions for the composition of the lower troposphere and the UTLS and investigate the effect of in-cloud oxygenated VOC (OVOC) oxidation during such a strong pollution event. This is achieved by performing multiple chemistry simulations using the global atmospheric model ECHAM/MESSy (EMAC). By comparing modelled columns of the biomass burning marker hydrogen cyanide (HCN) and carbon monoxide (CO) to spaceborne measurements from the Infrared Atmospheric Sounding Interferometer (IASI), we find that EMAC properly captures the exceptional strength of the Indonesian fires. In the lower troposphere, the increase in VOC levels is higher in Indonesia compared to other biomass burning regions. This has a direct impact on the oxidation capacity, resulting in the largest regional reduction in the hydroxyl radical (OH) and nitrogen oxides (NOx). While an increase in ozone (O3) is predicted close to the peatland fires, simulated O3 decreases in eastern Indonesia due to particularly high phenol concentrations. In the ASMA and the ITCZ, the upward transport leads to elevated VOC concentrations in the lower stratosphere, which results in the reduction of OH and NOx and the increase in the hydroperoxyl radical (HO2). In addition, the degradation of VOC emissions from the Indonesian fires becomes a major source of lower stratospheric nitrate radicals (NO3), which increase by up to 20 %. Enhanced phenol levels in the upper troposphere result in a 20 % increase in the contribution of phenoxy radicals to the chemical destruction of O3, which is predicted to be as large as 40 % of the total chemical O3 loss in the UTLS. In the months following the fires, this loss propagates into the lower stratosphere and potentially contributes to the variability of lower stratospheric O3 observed by satellite retrievals. The Indonesian peatland fires regularly occur during El Niño years, and the largest perturbations of radical concentrations in the lower stratosphere are predicted for particularly strong El Niño years. By activating the detailed in-cloud OVOC oxidation scheme Jülich Aqueous-phase Mechanism of Organic Chemistry (JAMOC), we find that the predicted changes are dampened. Global models that neglect in-cloud OVOC oxidation tend to overestimate the impact of such extreme pollution events on the atmospheric composition.

Multisite characterization of concurrent black carbon and biomass burning around COVID-19 lockdown period

The Magee Scientific Model AE33 Next Generation Aethalometer, installed at Amity University Haryana (AUH), Panchgaon (rural station) has been operated round-the-clock and obtained high-resolution (1–5 Minutes) observations of Black Carbon (BC) mass concentration at seven different sensing wavelengths (ranging from UV to NIR). For each observation, contribution from Biomass Burning (BB, in percent) to the BC has also been recorded. These measurements have been analyzed to segregate different sources, responsible for BC at this rural station. The results reveal that the major contributor is ‘traffic’ (fossil-fuel diesel emissions), followed by ‘biomass smoke’, wood-burning activities. The diurnal variation in BC and associated BB over this study area reveals a significant maximum around 0900 h and minimum around 1600 h. These maximum and minimum concentrations are attributed to transport activities during morning and ascending of local atmospheric boundary-layer height. The results also exhibit a strong affinity between BC mass concentration and coincident CO2 and PM2.5 mass concentrations. Synchronous BC measurements have also been organized over two more locations, namely, Bhopal (urban station) and Mahabaleshwar (high-altitude station). The black carbon aerosol transport through long-range air mass back-trajectories is explained.

Features of determination of native carbon in carbon-containing rocks on the analyzer of carbon and water

The largest deposits of graphite in the Russian Federation are located in the Middle and South Urals. However, several manifestations, e.g., «Opytnyi» sector, which have not yet been placed under production, require substantiation of the strategies for their integrated development, which, in turn, requires gaining the reliable data on the content of graphite in carbon-containing rocks. A method for simultaneous determination of organic and native carbon in carbon-containing rocks using an ELTRA CW MULTIPHASE carbon and water analyzer is proposed. The method is based on the combustion of organic carbon (coal, shale) in a stream of oxygen at 550°C and native carbon (graphite) in the temperature range 550 – 1000°C with subsequent IR-spectroscopic determination of the content of gaseous carbon dioxide. The interfering effect of magnesium carbonate and calcium carbonate on the determination of organic and native carbon was taken into account in the calculations. The carbonate content was determined using a separate sample in a nitrogen flow by decomposition of magnesium carbonate at 550°C and calcium carbonate within a temperature range of 550 – 1000°C. The content of chemically bound water in the composition of the minerals of carbon-containing rocks, was determined simultaneously with carbon. The only one type of carbon — graphite — was observed in the studied samples of the carbon-containing rock from «Opytnyi». The different combustion capacity of graphite was revealed: some of the crystals almost completely burn out at a temperature below 800°C and others above 800°C, which suggests the presence of cryptocrystalline and explicit crystalline graphite in the rocks. The developed method is rapid and corresponds in accuracy to the method for native carbon determination ±0.27 C % – 0.01 C % developed and approved by the Research Council for Analytical Methods of Research (NSAM).

Formation of mechanisms for creating innovative national polygons

Currently, the issues of environmental protection and conservation are becoming very acute. The development strategy of the world community is determined by the UN Sustainable Development Goals. According to this document, one of the priorities is to eliminate the harmful effects of carbon fuel emissions. In the world, about 80% of the energy produced is produced by burning carbon, which leads to the release of greenhouse gases into the atmosphere. Annual CO2 emissions reach 33.1 billion tons, causing irreparable damage to the environment. Our nature will continue to develop and evolve under these conditions, but the drastic climate change, global warming, and the mutation of flora and fauna are tasks that require immediate solutions. As a solution to these problems, we can offer the use of alternative energy sources. They represent promising ways to obtain, transfer and use energy from renewable sources, reducing the risk of harm to the environment. Also, to reduce harmful CO2 emissions into the atmosphere, methods for reducing greenhouse gas emissions are proposed, including carbon dioxide sequestration technologies, which are implemented in the form of CC (U) S (carbon capture, utilization and storage) projects. Another solution to the tasks set can be the creation of carbon landfills and farms that will allow us to develop technologies for monitoring carbon emissions and runoff.

CO2 Adsorption in a Geopolymer-zeolite Composite: Experimental Dynamic Tests and Modelling Insights on Related Thermal Effects

CO2 adsorption process in a composite geopolymer/zeolite 13X material has been analysed for post combustion carbon capture application, in dynamic conditions for a CO2/N2 gas mixture. Such composite material represents a valid alternative to conventional sorbents owing to the affinity and synergy between zeolite and the geopolymer binder as well as improved mechanical resistance and lower cost. Experimental analysis has been focused both on complete adsorption tests to determine the material maximum adsorption capacity and on breakthrough tests in transient conditions in (cyclic adsorption/desorption). Particular care has been devoted to thermal effects associated to adsorption and their effect on adsorption capacity and kinetics.Experimental data have been employed to support the development of a novel numerical model, based on Sips adsorption approach for sorbent capacity, and capable to describe the adsorption process, accounting for both mass and energy transport in the sorbent bed. The model proved able to describe well the experimental data at different CO2 feed concentration, and thus it has been employed in a predictive way to inspect process operating parameters and sorbent bed design on the resulting adsorption capacity, breakthrough time, and temperature profile. In particular, the model compared the results obtained in a scaled-up configuration (suitable to an industrial application) with those of the lab-scale system.

Influence of gaseous mixture parameters on the maximum burning temperature and combustion rate of carbon particle

The method is developed to determine the maximum temperature of burning carbon particle and corresponding value of particle diameter by using the maximum temperature as a parameter depending on surrounding gas temperature and oxygen content. This method allows finding a limiting value of oxygen content below which ignition of a carbon particle is not possible in cold oxygen-nitrogen mixture. It is shown that the particle temperature attains a maximum value in the transitional regime of chemical reactions. The rise of the burning temperature with the particle size decrease is caused by relative decrease of radiation heat loss.

Techno-economic analysis of co-combustion of Indian coals with municipal solid waste in subcritical and supercritical based steam turbine power generating carbon-negative systems

Incineration of municipal solid waste (MSW) can generate thermal energy for electricity generation and reduces its accumulation in the environment. MSW has low calorific value and its utilization would lead to low thermal efficiency in power plants due to higher auxiliary power consumption. Alternatively, this problem can be overcome by co-utilizing MSW with coal in thermal power plants. The capture of the generated CO2 from MSW can lead to carbon-negative energy production. Hence to evaluate its feasibility, energy and techno-economic analysis of subcritical and supercritical based steam turbines using MSW and its co-utilization with Indian high ash and low ash coals are performed using Aspen plus software (v 8.8). The effect of integrating post combustion carbon capture on the net thermal efficiency of power plants and its subsequent impact on levelized cost of electricity (LCOE) are analysed. The feedstock with an equal proportion of coal and MSW had shown a reasonable LCOE in the range of 60–67 $/MWh without carbon capture. The results had shown that the addition of 25% MSW to low ash coal could give a similar plant thermal efficiency and LCOE to that of high ash coal under subcritical conditions without carbon capture.

Combustion of hazelnut shell-lignite blends in poly-particulate beds

In this study, combustion behaviours of blends prepared from 2.18 mm mean size lignite and hazelnut shell particles in specific proportions were investigated using a vertical pre-heated furnace system through which air was flowing upwards by natural convection. The results revealed that the ignition time of the blends approached those of hazelnut shell with temperature and showed certain interactions of the two materials during the volatiles combustion period. Combustion time generally complied with volatiles and carbon combustion rates of the two materials and their blends. Carbon combustion time decreased with temperature and hazelnut ratio, and implied some interactions of the materials. Although any effect of initial furnace temperature and hazelnut ratio of the blends on the NOx emissions was not clearly seen, SO2 emission levels depended on these factors.