Chemical Reaction Process Research Articles

Interfacial Modification of a Zn Anode by Amorphous Se toward Long-Life and Hydrogen Evolution-Free Aqueous Rechargeable Batteries.

The Zn anode in rechargeable aqueous Zn-ion batteries suffers from hydrogen gas evolution and dendrite growth, which are critical issues that make the battery impractical. Here, the Zn anode performance is greatly improved by coating an amorphous selenium overlayer with a simple chemical bath reaction process. The reduction of SeO32- ions by the Zn metal leads to the formation of an amorphous Se layer, and the optimal reaction time that determines the thickness of the Se coating as well as the Zn anode performance is found to be 2 h. The symmetric cell using Zn@Se exhibits improved rate performance and an ultralong cycle life of 4500 h after being tested at 1 mA cm-2 and 1 mAh cm-2, respectively. Compared to the bare Zn anode, the Zn@Se anode leads to a larger Zn2+ transference number and reduced charge transfer resistance. The button-type MnO2∥Zn@Se full cell exhibits higher capacity and a much longer cycle life compared to the counterpart using a bare Zn anode. Also, pouch-type MnO2∥Zn@Se full cells with a high capacity of 9.7 mAh cm-2 are made to demonstrate the inhibition of hydrogen evolution and practical applications. It is found that the in situ formation of an amorphous ZnO nanosheet network induced by the amorphous Se overlayer plays a key role in enhancing the Zn anode performance.

Modeling of Multi‐Ion Plasma Bubbles in the Equatorial Ionosphere

AbstractEquatorial plasma bubbles (spread F/ionospheric irregularities) are plasma density irregularities or depletion in the ionosphere. It can be observed by radio waves, optical and in situ instruments during postsunset in equatorial and low‐latitude regions. Severe scintillations in radio waves can be caused by the presence of plasma bubbles. Therefore, studies of plasma bubbles become one of the most important and hot topics. Many studies have been devoted to the physical mechanism and characteristics of plasma bubbles in the ionosphere. However, some critical issues (e.g., day‐to‐day variability, complex structures, and ions composition) are still not well known. In this study, a new two‐dimensional model of multi‐ion (H+, He+, N+, O+, N2+, NO+, and O2+) plasma bubbles was developed. The photoionization, chemical reaction, and recombination processes of multiple ions have been added to the new model. The present model was used to simulate the nonlinear evolutions of multiple plasma bubbles in the equatorial region. Results show that the merging, disconnection and connection processes of plasma bubbles can be reproduced in this simulation. In addition, simulations first present morphological structures of molecular ions (NO+, O2+) of multiple plasma bubbles, which are significantly different from plasma bubbles. Molecular ion NO+ is manifested as plasma blobs. However, molecular ion O2+ is manifested as bubbles at low altitudes but blobs at high altitudes. The complex structures of multiple plasma bubbles and morphological structures of molecular ions in the present simulation are mostly consistent with observations.

Multi-scale dynamic mathematical model of CO2 and fly ash mineralization

The multi-scale structural characteristics of micro-nano pores of fly ash are the core factors affecting the mechanisms of physical transport and chemical reaction of CO2. The existing theoretical models of mineralization do not take such characteristics into account. it is difficult to describe the mechanisms of physical transport and chemical reaction of CO2. In order to address this scientific problem, a theoretical model of multi-scale structures of pore series is established. A mathematical dynamic model of multi-scale internal diffusion-mineralization is also established for accurately describing the concentration variation law in physical transport and chemical reaction processes of CO2 in micro-nano pores of fly ash under natural static conditions. The model is simulated to analyze the key parameters affecting the transport-mineralization reaction rate in the evolutionary mechanism of CO2. The simulated results showed that if the initial apparent diffusion-mineralization coefficient is reduced by 100 times, the concentration of CO2 at the center of the particles is reduced by 25 order in magnitude. The attenuation coefficient is reduced by 2 order in magnitude and the concentration of CO2 at the center of the particles is changed by 9 order in magnitude. These findings indicate that the initial apparent diffusion-mineralization coefficient and attenuation coefficient are the factors affecting the diffusion-mineralization reaction in the evolution of CO2. The reason for the phenomenon of multi-scale evolution and mechanism of diffusion mineralization reaction of CO2 in the micro-nano pores of fly ash is revealed.

Preparation and electrochemical performance study of a self-healing electrode composite material with WSe2/liquid metal Galinstan for lithium-ion batteries

In this work, a room temperature liquid metal alloy (Galinstan) and tungsten diselenide (WSe2) composite anode (LMx@WSe2) were synthesized utilizing a one-step hydrothermal method. Through a comprehensive characterization process, including XRD, SEM, HRTEM, Raman spectroscopy, XPS, and BET, the structural and morphological properties of the synthesized composites were extensively explored. The liquid metal alloy was observed to combine effectively with WSe2 via electrostatic adsorption, coordination, and additional bonding methods. Furthermore, it displayed high fluidity, deformability, and chemical stability. Consequently, the alloy promoted the repair of cracked surface areas in the electrode material and reduced internal oxidation-reduction reactions, leading to improved electrochemical performance during repeated lithium-ion insertion and extraction cycles. After 500 cycles at a current density of 1 A g−1, this composite electrode retained a capacity of 224.5 mAh g−1. Impressively, at a low temperature of − 10 °C, it maintained a capacity of 290 mAh g−1 after 50 cycles at a current density of 0.2 A g−1. Our research may open avenues for addressing mechanical difficulties experienced in flexible electronic devices and self-healing electronic circuits exposed to chemical reaction processes.

Volatilization of sodium and boron from nuclear waste glass and associated effects on glass structure and thermal stability

During nuclear waste vitrification, loss of sodium (Na) and boron (B) occurs, as these elements are highly volatile at high temperatures, which affects the properties of the glass products. Moreover, the evaporation of volatile nuclides (Cs and Tc) occurs together with that of Na and B, which may cause environmental hazards. Thus far, only a few studies have focused on the volatilization of Na and B from nuclear waste glass and loss-related effects on glass properties. In this study, we investigated the volatilization behaviors of Na and B from a simulated high-level waste glass as functions of heating temperature and dwelling duration, and evaluated the effects of Na and B loss on the glass structure and thermal stability. The results showed that volatilization of Na occurs predominantly through the diffusion-controlled process at a temperature range of 950 °C to 1100 °C, and owing to its higher frequency factor, Na diffuses and volatilizes at a faster rate than that of B. Volatilization of B occurs by both a diffusion-controlled process from bulk to the surface and a chemical reaction process on the surface. Based on the data obtained regarding the composition of Na and B and structure of the glass, a hypothetical model was proposed to explain the volatilization behaviors of Na and B from a structural viewpoint. As the loss of Na and B increases, the amount of BO4− reduces, whereas the amount of BO3 increases; finally, the Si-O network becomes more polymerized and has less thermal stability, resulting in the crystallization of the glass at elevated temperatures. These results would serve as the basis to estimate the amount of Na and B loss and the properties of the glass melt during nuclear waste vitrification, especially in melter idling.

Simulation of localized electron density enhancement caused by high-pressure H2O gas release in ionosphere

Based on the continuity and momentum equations, a self-consistent simulation model is developed for describing the localized electron density enhancement caused by high-pressure H2O gas release in the ionosphere. The chemical reaction and momentum exchange process between the neutral gas and ionospheric plasma species are considered in the theoretical simulation model. The finite element method is used to solve the simulation model for H2O gas release, and the expansion and ionospheric disturbance process at the early stage of high-pressure gas release are studied. It is shown that the space expansion of the released gas is mainly dominated by the pressure difference between the H2O gas and the ionospheric plasma at the early stage of release. Then the diffusion process becomes the dominant process of the space transport of H2O molecules. An electron depletion region forms near the center of the release region due to the chemical reaction and collision process with H2O molecules. Meanwhile, an electron density enhancement region forms on both sides along the magnetic field direction due to the electron snowplow effect. With the increase in the released mass of H2O gas, the intensity and duration of the electron density enhancement increase gradually. With the release position rising, it is found that the intensity of the electron density enhancement has a peak near 380 km and the duration increases slightly with the increasing release height.

(Invited) novel Charged Interfaces for Catalysis and Energy Conversion

Charged interfaces are ubiquitous in many research fields such as electrochemistry, catalysis, and energy chemistry, and are key places where physical and chemical processes occur. The charged interface structure can also be affected by external fields such as light, electricity, and force, and becomes the key to regulating chemical reactions. It is of great significance for the development of surface and interface science, electrochemistry, catalysis and energy science to deeply understand the physical and chemical reaction process and mechanism of various charged interface systems, and to clarify the interaction between interface structure and reacting species. It is extremely challenging to rationally design, construct, and characterize various novel charged interfaces, and then comprehensively and deeply study their physical and chemical processes and mechanisms. By constructing new charged interface structures such as solid/solid triboelectric interface, micro-droplet charged liquid/gas interface, and metal/two-dimensional material charged interface, we study the reaction process and mechanism of the charged interface and develop new energy conversion pathways. A series of innovative research results: Discovered a new mechanism of triboelectric power generation, expanding the new direction of charged interface structure in energy conversion; established and developed epitaxial growth modes of various interface structures; accurately characterized the electron transport of charged interface structure and surface charge distribution and other physical and chemical properties. We have developed new systems such as solid/dielectric/liquid charged interfaces based on electrodes/dielectric layers/electrolytes and liquid/gas charged interfaces based on microdroplets, and explored new applications in energy conversion and electrocatalysis. Applying a voltage to the electrode/dielectric layer/electrolyte interface can polarize the dielectric layer and adsorb ions in the electrolyte, forming a special "sandwich" electric double layer. Different from the solid/solid charged interface formed by triboelectrification or light excitation, this is a new solid/dielectric/liquid charged interface system based on electrostatic adsorption. Based on this interface system, a new nanoscale power generation device is designed, which can effectively convert mechanical energy into electrical energy, and has high output performance. A new liquid/gas charged interface based on micro-droplets was constructed by means of electrospray, a new strategy for confining the liquid/gas charged interface was proposed, and a high-performance electrolytic water catalyst was prepared. The physical and chemical mechanism of accelerated chemical reactions at the liquid/gas charged interface is revealed, and the desolvation effect and interface confinement effect are proved to be effective ways to construct defect-rich electrocatalysts.

Lattice oxygen migration of iron-based oxygen carrier during chemical looping reaction process

Chemical looping combustion relies on high performance oxygen carriers (OCs). Iron-based OCs have excellent overall properties, but the disadvantage of low reduction reactivity limits their application prospects. Clarification of oxygen transfer pathways and bulk phase properties is essential to improve oxygen transfer rates and increase the reactivity of OCs. High-resolution transmission electron microscopy, electron energy loss spectroscopy and X-ray photoelectron spectroscopy had been used to study the lattice oxygen transport properties, the Fe and O elemental contents and Fe elemental valence changes at different positions on the radial surface of Fe2O3 OC, as well as the related elemental compositions, atomic valence and surface energy distribution on the surface of the OC during the reduction process of OC. The results show that during the reduction process, the active components at different locations of the OC are simultaneously reduced and lattice oxygen is released. Both internal and external lattice oxygen are involved in the reaction. Besides, reaction interface is believed to be fixed at a OC surface. This study reveals the migration direction of the reduction interface and the mechanism of oxygen release in the bulk phase, and would provide a theoretical basis for the structural design of Fe-based OCs.

Theoretical model and simulations to extract chemical reaction parameters ruling resistive switching in sputter-deposited silicon oxide film on Si substrate

This paper proposes a physics-based model based on possible chemical processes responsible for the resistive switching of sputter-deposited silicon oxide films. Diffusion–reaction differential equations are utilized to pursue physical and chemical origins of the switching phenomenon. Based on the theoretical model, the chemical reaction process is analytically and numerically solved, and an analytical model is proposed to elucidate the phenomenon. Theoretical simulation results are examined from the point of view of suitability of parameter values, and the analytical model is used to interpret the simulation results. Simulation results greatly assist in understanding the switching processes of silicon oxide films; that is, the diffusion processes of hydrogen and water molecules primarily rule the switching processes, and the displacement of oxygen atoms is assisted by those processes. The analytical model predicts that high-speed switching requires a large number of traps in the oxide, a relatively large binding energy, and a low leakage current; all of them can easily be satisfied for sputter-deposited oxide films. A combination of the theoretical simulation model and the analytical model gives a guideline of how the sputter-deposited silicon oxide films can be made suitable for high-speed resistive switching applications.

Intelligent identification method of chemical processes based on maximum mean discrepancy domain generalization

BackgroundBenefiting from the massive process data stored in the plant distributed control system, the identification of chemical processes using deep learning methods has been widely studied. However, the statistical characteristics of chemical process data often change over time due to random interference caused by environmental impacts, the complexity and variability of chemical reaction processes, and changes in operating conditions. This makes the model obtained by the deep learning method based on the assumption of independent identical distribution sensitive to distribution changes. MethodsA neural network identification method based on multi-domain multi-kernel maximum mean discrepancy (MD-MK-MMD) domain generalization is proposed. The identification data is split with the maximum average distance to maximize the difference in the distribution of identification data. The MD-MK-MMD domain generalization method is adopted to reduce distribution difference and learn model parameters. Based on the gate recurrent unit (GRU) model and combined with MD-MK-MMD domain generalization, an intelligent identification framework for chemical processes is constructed. Significant findingsExperiments on actual process datasets of a heating furnace and a fractionator show the effectiveness of the proposed chemical process identification framework. The errors of the MD-MK-MMD domain generalization based identification method on the test sets are lower than that of the state-of-the-art neural network-based identification methods, which means the proposed method reduces the model sensitivity to the identification data distribution changes.

Simultaneous leaching and separating of palladium from spent palladium catalyst by tribromide ionic liquids as non-volatile oxidizing solvents

The recovery of palladium (Pd) from secondary resources has attracted much attention because of its unique environmental effects and economic value. A novel technique for the oxidation, dissolution, and separation of precious metals is presented in this paper. Tribromide ionic liquids (ILs) with low viscosity, high stability, and strong oxidation were synthesized and applied for the one-step leaching and separation of Pd from spent Pd-Al2O3 catalysts. Through the preliminary performance test, [C1C12PYR]Br3 was selected as the optimal leaching agent from three kinds of tribromide ILs, and the reasons for the obvious difference in leaching ability were analyzed from the perspective of quantum chemistry.The optimum leaching conditions were determined as follows: leaching time was 12 h, leaching temperature was 45 °C, and the dosage of [C1C12PYR]Br3 was 0.8 g (the mass of fixed Pd was 20 mg). Under these conditions, the leaching efficiency (η%) can reach 94.82%. By optimizing the response surface methodology (RSM) model, the leaching temperature in the actual system was determined to be 50.28 °C, and the dosage of [C1C12PYR]Br3 was 0.74 g, which achieved the best economic value of the system. Using XPS, HPLC, and EDS, the leaching mechanism of Pd was demonstrated to be a process that combined redox with coordination and complexation. The kinetic study shows that the rate control step of the leaching process was a chemical reaction process. The 20% hydrazine hydrate can achieve efficient (99%) stripping of Pd in the IL phase. As a result of the leaching agent's good selectivity and reusability when used to recover spent Pd-Al2O3 catalyst, [C1C12PYR]Br3 is regarded as a promising precious metal leaching agent.

Stable oxygen permeable membrane with Ce0.9Gd0.1O2-δ protective layer for syngas production

The stability of catalytic membrane reactors (CMRs) is crucial for the practical applications in chemical reaction processes. However, currently reported CMRs with perovskite-based oxygen permeable membranes usually show poor stability owing to the over-reduction of Co and Fe ions in perovskite lattice under harsh reducing gas atmospheres and the interaction between membrane and catalyst. Here we developed an oxygen permeable membrane Ce0.9Gd0.1O2-δ-SrCe0.5Fe0.5O3-δ (CGO-SCF) with Ce0.9Gd0.1O2-δ (CGO) protective layer to construct a catalytic membrane reactor packed with Ni/Al2O3 catalyst for partial oxidation of methane. The CGO dense protective layer can effectively avoid the over-reduction of Fe ions in perovskite under harsh reducing gas atmospheres and the interaction between perovskite and Ni/Al2O3. Benefiting from high stability and mixed ionic-electronic conductivity of CGO in a low oxygen partial pressure environment, the developed membrane reactor with a dense CGO thin film was successfully operated with a stable CH4 conversion of 87% and a H2/CO ratio of 2 over 200 h in harsh operating conditions. This strategy proposed here provides insights into the design of highly stable catalytic membrane reactor in harsh conditions.

Research on the Optimization of the Operating Parameters of Methane Carbon Dioxide Reforming Using the Response Surface Methodology

In order to reduce the production cost of the methane carbon dioxide reforming reaction, and improve its actual production efficiency, in this paper, the optimal working parameters of the methane carbon dioxide reforming reaction are studied. The influence of different factors on methane conversion is studied via a single-factor numerical simulation analysis and the response surface methodology. Firstly, a numerical model of the methane carbon dioxide reforming reaction is established using Ansys Chemkin Pro software to analyze the influence of single factors (reactor temperature, reaction pressure, gas velocity) on methane conversion rate; secondly, the response surface model with the methane conversion rate as the response value is established using the BBD (Box–Behnken design) method; and finally, the order of influence of each variable on methane conversion and the optimal reaction conditions are determined using the response surface method. The factors are listed in order of their influence on methane conversion as follows: reactor temperature > pressure > speed. The results show that when the temperature is 1135.114 K, the pressure is 0.103 MPa and the speed is 10slpm, the methane conversion rate is 93.7018%. In this paper, a method is adopted in which chemical reaction process simulation and numerical results prediction are combined, significantly reducing the simulation time and improving the calculation efficiency and accuracy, thus being of considerable scientific significance and theoretical value.

Self‐trigger and on‐demand drug delivery system based on TiO2 nanotube arrays and its drug release behaviour

AbstractThe foundation of drug delivery systems based on titanium dioxide nanotube arrays has become an important means to increase the drug release performance of bone implantation materials. However, most of the conventional platforms have some disadvantages, such as large sudden release, uncontrollable, unintelligent, or not on‐demand drug release process. Herein, the authors develop a unique self‐triggering drug release system (SDDS), utilizing the advantages of 1‐Tetradecanol (TD), such as decent biocompatibility, a phase transition temperature of 37.8°C, and the inexistence of complex chemical reaction process. The establishment of the platform can make a large amount of the anti‐inflammatory drug (ibuprofen, IBU) released when the body or the affected area is inflamed, that is, when the temperature rises. Conversely, only a small amount or no drug is released when there is no inflammation, thereby achieving self‐trigger release and on‐demand release. The experimental results show that the system combines good self‐trigger release properties, release sensitivity, drug release cycle, and low selectivity to the loaded drugs.

Non-equilibrium modeling on the aerothermodynamic characteristics of hypersonic inflatable reentry vehicle

In this study a 2D two-temperature chemical non-equilibrium model is established to investigate the flow characteristics and chemical reactions processes around hypersonic inflatable reentry vehicle at different flight altitudes and reentry velocities. This chemical kinetic model is based on the Gupta model and modified by comparing the species mole fractions at thermal equilibrium condition with the results obtained by Saha equation. In order to validate the model, the calculations are performed for a blunt cone ELECTRE and a cylinder, the predicted heat flux and pressure are compared with experimentally measured data and the maximum differences on heat flux and wall pressure are less than 20% and 5%, respectively. Then the flow characteristics behind the shock wave and wall heat flux are discussed in detail for Titans vehicle. It is found that the pressure declines with the increase of altitude and reentry velocity, this variation trend is opposite to the wall heat flux, whose maximum value increases from 58 kw/m2 to 107 kw/m2 with the rise of flight altitude from 79 to 88 km due to the large temperature and component gradients. This indicates that the aerodynamic force and heat flux should be taken into account simultaneously for the design of inflatable reentry vehicle. By analyzing the chemical reactions processes behind the strong shock wave, it is seen that not only the dissociation reactions of N2 and O2 molecules play an important role, but also the neutral species exchange reactions contribute to the density change of species. The dominant ionization reactions are N+O→NO++e and NO+M→4NO++e+M4, while the ionization processes are weak, and the maximum ionization degree is smaller than 1%. The analysis of dominant chemical reactions can provide a reference for the numerical modeling study of hypersonic reentry vehicle.

Unraveling segregation behavior of inactive secondary phase driven by ion-competition reaction for perovskite-2D PbI2 heterojunction solar cells

The undesired segregation of inactive secondary phase that randomly distributed across the perovskite film is detrimental to charge-carrier transport dynamics and light stability. However, in-depth studies for understanding the underlying chemical reaction mechanism and the relationship between phase structural configuration and physical properties are still lacking. Herein, the segregation behavior of the inactive secondary phase and the underlying microcosmic mechanism regarding ionic chemical replacement reaction and lattice reconfiguration process are systematically elaborated. A high-quality perovskite-PbI2 heterojunction film is constructed via converting the three-dimensional PbI2 photoactive phase into a two-dimensional inactive phase, alleviating the energetic disorder of carrier dynamics and photochemical dissociation. The resultant perovskite solar cells achieve an efficiency of 24.23% with excellent light-resistance. The dissociation energetics of phase dimensional structure is theoretically analyzed. This work provides new insights into crystal structure design for constructing high-quality perovskite heterojunction devices.

Comparison of the heterogeneous reaction of NO2 on the surface of clay minerals and desert dust particles

Mineral particles in air could provide atmospheric chemical reaction interface for gaseous substances and participate in atmospheric chemical reaction process, and affecting the status and levels of gaseous pollutants in air. However, differences of the heterogenous reaction on the surface minerals particles are not very clear. Considering main mineral composition of ambient particles was from dust emission, therefore, typical clay minerals (chlorite, illite) and desert particles (Taklimakan Desert) were selected to analysize chemical reaction of NO2, one of major gaseous pollutants, on mineral particles by using of In-situ DRIFTS (diffuse reflectance infrared Fourier transform spectroscopy) under different condition. And In situ near-ambient pressure X-ray photoelectron spectroscopy (In situ NAP-XPS) was employed to investigate iron (one of the major metals) species variation on the surface of mineral dust particles during the heterogeneous reactions. Our data show that humidity controlled by deuterium oxide (D2O) has a greater effect on chemical reactions compared to light and temperature. Under dry conditions, the amount of heterogeneous reaction products of NO2 on the particles shows Xiaotang dust > chlorite > illite > Tazhong dust regardless of dark or light conditions. In contrast, under humidity conditions, the order of nitrate product quantity under moderate conditions was chlorite > illite > Xiaotang dust > Tazhong dust. In situ NAP-XPS results demonstrate that specie variation of the Fe could promote the heterogenous reactions. These data could provide useful information for understanding the formation mechanism of nitrate aerosols and removal of nitrogen oxides in the atmosphere.

High-throughput synthesis of size-controlled Pt-based catalysts

Pt catalysts are commonly used for chemical reaction processes due to its high catalytic activity and selectivity. Notably, the size of metal particles often has a significant impact on the performance of the metal-loaded catalysts. Therefore, developing highly efficiently synthesis method for the size control of Pt catalysts has great development prospects and research value. In this study, high-throughput size tuning of Pt-based catalysts was achieved by carbonizing the carriers. The experimental and characterization results showed that the size of the loaded Pt nanoparticles varied with different concentrations of glucose solution during carriers carbonization process. The reduction of 4-nitrophenol as a template reaction indicated that the reaction rate constant of the catalyst is approximately linear with the size of Pt particles. Importantly, a laboratory-built high-throughput synthesis system was applied for the catalyst synthesis, which enhances the automation of the laboratory exploratory experiments and makes it possible to synthesize catalysts with controllable size in batches.

Chemical reaction-mass transport model of Ga2O3 grown by TEGa in MOCVD and an intelligent system

Gallium oxide (Ga2O3) is rationally expected to have a wide range of applications prospects in power electronics, solar-blind UV detectors, gas detectors, and other fields. Metal-organic chemical vapor deposition (MOCVD) is a key technology for achieving high-quality and large-scale film growth, but with complex fluid fields, temperature fields, component distribution, and chemical reaction processes, the process is akin to a black box. In this study, the computational fluid dynamics (CFD) approach and a complete reaction mechanism were used to model the chemical reaction and mass transport for gallium oxide film growth based on a vertical rotating disc reactor (RDR) MOCVD system. The effect of temperature on film growth was explored and analyzed. It was found that the growth temperature can be divided into four regions, respectively controlled by thermal flow field, reaction rate, component transport, and parasitic reaction, and there is a competitive relationship between them. In the component transport region, the influence of different process parameters such as pressure, flow rate, and rotational speed on the growth was investigated. The regulation of film uniformity is achieved by the coupled regulation of 5 pairs of MO source inlets and multiple process parameters. Combined with artificial intelligence techniques, an intelligent system for realizing flow field visualization, growth result prediction, process parameter optimization, and abnormal result tracking was proposed for the first time. It can provide systematic guidance for film growth.

Investigation of the Efficiency of a Dual-Fuel Gas Turbine Combustion Chamber with a Plasma‒Chemical Element

Abstract The study is devoted to the possibility of increasing the efficiency of the working process in dual-fuel combustion chambers of gas turbine engines for FPSO vessels. For the first time, it is proposed to use the advantages of plasma‒chemical intensification of the combustion of hydrocarbon fuels in the dual-fuel combustion chambers, which can simultaneously operate on gaseous and liquid fuels. A design scheme of a combustion chamber with a plasma‒chemical element is proposed. A continuous type mathematical model of a combustion chamber with a plasma‒chemical element has been developed, which is based on the solution of a system of differential equations describing the processes of chemical reactions in a turbulent system, taking into consideration the initiating effect of the products of plasma‒chemical reactions on the processes of flame propagation. A modified six-stage kinetic scheme of hydrocarbon oxidation was used to simultaneously predict the combustion characteristics of the gaseous and liquid fuels, taking into account the decrease in the activation energy of carbon monoxide oxidation reactions when the products of the plasma‒chemical element are added. The results reveal that the addition of plasma‒chemical products significantly reduces CO emissions in the outlet section of the flame tube (from 25‒28 ppm to 3.9‒4.6 ppm), while the emission of nitrogen oxides remains practically unchanged for the studied combustion chamber. Further research directions are proposed to enhance the working process efficiency of a dual-fuel combustion chamber for gas turbine engines as part of the power plant of FSPO vessels.