Heterogeneous Reactor Model Research Articles

Investigation of dissolution kinetics of colemanite in propionic acid solutions

ABSTRACT Colemanite is one of the raw materials used to produce boron compounds which have a constituent of the richest composition ratio boron trioxide ( B 2 O 3 ) . The main purpose of this study is to investigate the dissolution kinetics of colemanite in a propionic acid solution. Reaction temperature, solid–liquid ratio, propionic acid concentration, stirring speed, and particle size were chosen as relevant parameters in the dissolution. According to the results of the study, the dissolution rate was directly proportional to the rise in the reaction temperature and inversely proportional to the increase in the solid–liquid ratio, acid concentration, and particle size. Additionally, it was observed that stirring speed did not significantly effect. Experiment results were correlated with the use of the Statistica10 software programme for linear regression. For the dissolution kinetics of colemanite, a model that can control the reaction was obtained by using homogeneous and heterogeneous reaction models. It was determined that the dissolution rate of the process was controlled by diffusion through the product film (ash) and the Activation energy was calculated as 37.51 kJ . mo l − 1 . Experimental data were analyzed with graphical and statistical methods, and a semi-empirical mathematical model was determined, which included the parameters of the study.

Dissolution behavior and kinetic investigation of in solution in the reaction of colemanite ore with propionic acid

Colemanite ore, which is one of the most significant commercially substantial boron minerals, is used to produce various boron compounds in the industry with its rich B_2 O_3 content. Calcium propionate, used in the food industry, is formed as a by-product in its production. In the production of boric acid from colemanite, the use of different solvent reagents is at the forefront to prevent the formation of Mg^(2+), Ca^(2+) and SO_4^(2-) impurities and borogypsum by-products. For this reason, in our study, the dissolution kinetics of colemanite ore in propionic acid solution in an aqueous medium were carried out in a batch reactor system. As dissolution parameters; reaction temperature, solid/liquid ratio, propionic acid (CH_3 CH_2 COOH) concentration, stirring speed and particle size were selected as. According to the experimental results, the amount of Mg^(2+) passed to the solution; was observed that the solution increased with the increase in reaction temperature with the decrease in solid-liquid ratio, grain size, and acid concentration. In addition, it was determined that the mixing speed was not effective. Obtained experimental data were analyzed according to homogeneous and heterogeneous reaction models using the Statistica 10.0 package program. It was determined that the dissolution kinetic of Mg^(2+) passing to solution conformed to the "Avrami model" and activation energy (E) was calculated as 8.18 kJ⁄mol.

Isothermal calcination kinetics of boric acid and its use for nano boron oxide production under cryogenic conditions

The isothermal calcination kinetics of H3BO3 to B2O3 was firstly investigated as a function of time at 160, 200, 240 and 280 °C using heterogeneous and homogeneous reaction models and were characterized by XRD, FTIR-ATR, SEM and DTA/TG devices. Peaks in XRD patterns and bands in FTIR-ATR spectrum confirmed the structure of H3BO3 and B2O3. SEM showed that H3BO3 had a rather clean, flaky, smooth and plate-shaped surface while B2O3 had a rough surface. TG analysis confirmed that H3BO3 was degraded in two steps. Avrami model fitted a very good agreement with the experimental data. The activation energy was calculated as 14.2 kJ/mol. The smallest particle size for nano B2O3 was measured as 33 nm with Zetasizer NanoS. TEM images also confirmed that the particle size of B2O3 was measured to be approximately 50 nm. Additionally, the BET surface area of nano B2O3 was determined as 10.8 m2/g.

Kinetic study and advanced decomposition models of superthermite-based nitrocellulose nanocomposite

ABSTRACT Superthermites are well-known for their exceptional combustion characteristics. α ferric oxide nanoparticles (NPs) were synthesized using hydrothermal synthesis. Co-precipitation technique was employed to integrated superhermite (Al/Fe2O3) colloidal particles into nitrocellulose (NC) energetic matrix. Morphology NC nanocomposite was investigated using scanning electron microscope. The integration of superthermite particles into NC matrix experienced enhanced decomposition enthalpy by 40% using Differential Scanning Calorimetry (DSC) as the decomposition enthalpy has incresed to reach above 1640J/kg. In the mean time, superthermite particles offered decrease in NC activation energy by 17.3% and 16.0% using Kissinger-Akahira-Sunose (KAS) approach and Kissinger models, respectively. The hydrous surface of ferric NPs could secure novel catalytic action. At low temperatures, the reactive hydroxyl groups could be released; active ȮH radicals would attack the NC heterocyclic ring and abstract hydrogen atom. Addition of NPs enhanced the rapid release of different decomposition products of NC such as NO2 ,CO, NO, HCHO, and HCOOH at low temperature. Kinetic models indicated that the heterogeneous solid-state reaction and A2 nucleation model were confirmed via KAS and Kissinger models.

Influence of Physico-chemical Conditions on Mobility of Uranium from Wastes

Dynamic leaching tests were carried out on solid wastes generated from the uranium mining and milling industry under different physico-chemical conditions to assess the mobility of uranium from these matrices. The mobile/ soluble fraction of uranium leached out very slowly; being faster in the initial stages and then attaining a near steady state condition in most cases. Uranium leaching was observed to increase with decreasing initial pH, reducing particle size and increasing temperatures. A maximum of 2.4% uranium was leached out under highly acidic conditions in the experimental time period. Leachability index values indicated weak leaching of uranium from the wastes under all conditions. Leaching kinetics was examined with the help of a heterogeneous reaction model. Model results and apparent activation energy values indicated the leaching process to be initially reaction controlled and subsequently diffusion controlled. The apparent rate constants displayed dependence on the particle sizes of the tailings. All results obtained from this study imply that the extent of uranium leaching from these solid mining wastes is extremely low. This indicates low mobility and negligible transfer to other environmental compartments.

Effect of TiO2 on Pd/La2O3-CeO2-Al2O3 Systems during Catalytic Oxidation of Methane in the Presence of H2O and SO2.

New results on the effect of TiO2 on Pd/La2O3-CeO2-Al2O3 systems for catalytic oxidation of methane in the presence of H2O and SO2 have been received. Low-temperature N2-adsorption, XRD, SEM, HRTEM, XPS, EPR and FTIR techniques were used to characterize the catalyst. The presence of Ce3+ on the catalytic surface and in the volume near the lantana was revealed by EPR and XPS. After aging, the following changes are observed: (i) agglomeration of the Pd-clusters (from 8 nm to 12 nm); (ii) transformation of part of the TiO2 from anatase to larger particles of rutile; and (iii)-the increase in PdO/Pd-ratio above its optimum. The modification by Ti of the La2O3-CeO2-Al2O3 system leads to higher resistance towards the presence of SO2 most likely due to the prevailing formation of unstable surface sulfites instead of thermally stable sulfates. Based on kinetic model calculations, the reaction pathway over the Pd/La2O3-CeO2-TiO2-Al2O3 catalyst follows the Mars-van Krevelen mechanism. For evaluation of the possible practical application of the obtained material, a sample of Pd/La2O3-CeO2-TiO2-Al2O3, supported on rolled aluminum-containing stainless steel (Aluchrom VDM®), was prepared and tested. Methane oxidation in an industrial-scale monolithic reactor was simulated using a two-dimensional heterogeneous reactor model.

Simultaneous Bulk- and Surface-initiated Living Polymerization Studied with a Heterogeneous Stochastic Reaction Model

Simultaneous Bulk- and Surface-initiated Living Polymerization Studied with a Heterogeneous Stochastic Reaction Model

Evaluation of the relevant mass and heat transfer phenomena in a packed bed membrane reactor for the direct conversion of CO2 to dimethyl ether

This study investigates the relevant heat and mass transfer phenomena occurring at the different scales in a packed bed (membrane) reactor for the direct conversion of CO2 to dimethyl ether (DME) via the implementation of 2D heterogeneous reactor models. Intra-particle diffusion limitations were found to be relevant for particle diameters larger than 1 mm and temperature above 220 ⁰C, such that the catalyst efficiency drops down to 50% and 5% for the Cu/ZnO/Al2O3 and the HZSM-5, respectively, in the most critical conditions (i.e., 270 ⁰C and Dp of 10 mm). A component-specific Thiele modulus-efficiency correlation was developed based on the results of the rigorous particle model to account for pore-diffusion limitations without having to solve a complex heterogeneous reactor model. This correlation shows the typical behavior reported in literature for power law kinetics and accurately predicts the reaction performance with deviation of less than 5% for values of the Thiele modulus lower than 2. In the packed bed membrane reactor (PBMR), the concentration polarization (CP) also showed to affect the reactor performance. The concentration of water at the surface of the membrane selective layer was found to be up to 64% lower than the concentration in the bulk phase, hindering the effectiveness of the membrane separation. To account for this phenomenon via a simplified approach, a Sherwood-type correlation was developed to determine a CP mass transfer coefficient, based on the results obtained via the rigorous 2D PBMR model. Such correlation showed to predict with high accuracy (i.e., errors lower than 5%) the effect of the CP on the PBMR performance. Differently from the pore diffusion and CP phenomena, the intra-particle heat transfer, the particle–fluid mass and heat transfer as well as the axial dispersion were found to have a negligible effect on the reactor behavior. Finally, given the relevant mass/heat transfer phenomena, this study proposes further reactor optimization strategies, such as the reduction of the zeolite loading in the bifunctional catalyst bed by ca. 90% with respect to what is reported in literature.

A mesoscale model for heterogeneous reactions in porous media applied to reducing porous iron oxide

A mesoscale model based on the lattice gas cellular automata (LGCA) is proposed for heterogeneous reaction in porous media. This model features an entirely discretized reaction system, including discrete space, time, gas phases, and solid particle. To describe gas diffusion at solid nodes and gas–solid heterogeneous reaction on the phase boundary, two local probabilities are proposed, which are verified by the analytical solutions for gas diffusion and gas–solid reaction problems. This model was then applied to the hydrogen reduction of porous Fe3O4. The effects of the porosity, reaction rate constant (kl), and initial H2 concentration on the reduction were analyzed. The results indicate that the reaction rate increased with increasing porosity, kl, and H2 concentration. The solid product Fe was randomly distributed on the framework of Fe3O4 at smaller kl and concentrated around the unreacted Fe3O4 at higher kl, which is consistent with our experimental results.

Rapid removal of methylene blue by a heterogeneous photo-Fenton process using economical and simple-synthesized magnetite–zeolite composite

A hetero-Fenton zeolite-supported Fe3O4 catalyst was synthesized using a simple impregnation–precipitation method. The structure, morphology, and components of the catalyst were characterized using various analytical methods (XRD, SEM, and ICP-MS). Subsequently, the catalyst was used to degrade the azo dye methylene blue (MB), via a heterogeneous photo-Fenton process under UV irradiation in an aqueous solution. This study investigated the influence of different parameters on MB decolorization efficiency, such as the initial concentration of hydrogen peroxide, amount of catalyst, initial dye concentration, and reusability of the catalyst. The removal efficiency was nearly 100% within only 5 min with an initial concentration of methylene blue of 50 mg L−1 under the following experimental conditions: a pH solution of 3, a catalyst of 0.6 g L−1, an H2O2 concentration of 66 mg L−1, and a UV lamp power of 6 W. Moreover, the Fe3O4/zeolite A catalyst (Fe/ZA) showed good stability in the photo-Fenton degradation of methylene blue after four consecutive cycles, implying that the Fe/ZA catalyst could be a potential wastewater treatment option. Furthermore, the findings of the reaction kinetics study demonstrate that the kinetics of the dye removal reaction can be fitted using the Langmuir–Hinshelwood model for heterogeneous catalytic reactions.

Modeling of catalyst poisoning during hydrogen production via methane steam and dry reforming

A key aspect of biogas reforming is the frequent presence of hydrogen sulfide in such gases, and its negative poisoning impact on reactor performance. In this work, we present a modeling framework which is used to simulate the performance of a biogas-reforming reactor undergoing deactivation. A simplified heterogeneous reactor model is proposed to simulate deactivation results found within the literature, with validation of the reactor model completed against literature modeling data. Good agreement was found between literature data and simulated results calculated here. This agreement was found in spite of having tested reference data against a proposed quasi-uniform poisoning condition to assess the suitability of assuming shell-progressive poisoning to be insignificant. Further, this agreement was achieved by assuming an order of deactivation of n=1, in contrast with the more common assumption of n=3 for steam methane reforming. Discussion and comparison between these results and other studies noted in literature indicate, however, that the proposed order of deactivation is not necessarily implausible. Lastly, an industrial parametric case study using this model is presented, and thoughts regarding its use in analysis of real reactors is given.

Heterogeneous Reaction Model for Evaluating the Kinetics of Levulinic Acid Synthesis from Pretreated Sugarcane Bagasse

The abundance of sugarcane bagasse, a by-product of sugarcane juice extraction in sugar factories, serves as an advantage of its potential for producing chemicals such as levulinic acid (LA). Levulinic acid contains carbonyl and carboxyl groups that can be utilized for many applications, such as pharmacies, cosmetics, and solvents. Bagasse hydrolysis into LA was preceded by alkaline-acid pretreatment to separate cellulose from hemicellulose and lignin. This treatment could minimize the disturbance of these unwanted components, so that LA synthesis would be more optimal. Pretreated bagasse contained 82.64% cellulose, about two-fold from the non-pretreated one. It was hydrolyzed with hydrochloric acid (HCl), which acts as a catalyst (a Bronsted acid), at 150-170 oC, 0.1-1 M catalyst concentration, 1-10% solid-to-liquid (cellulose:catalyst-solution) ratio, and 0-200 minutes reaction time. The range of LA yield values obtained in the study were between 15-64.05%. The maximum LA yield was obtained at a temperature of 160 oC, 1 M catalyst concentration, and 1% solid-to-liquid ratio. The high LA yield indicates the importance of pretreatment supported by optimal conditions of synthetic reaction. The reaction route involved in hydrolysis was cellulose-glucose-levoglucosan (LG)-hydroxymethylfurfural (HMF)-LA. The result exhibits that temperature and catalyst concentration do not significantly affect the maximum potential LA yield. However, higher temperatures and catalyst concentration can accelerate the time to achieve the maximum potential LA yield. Meanwhile, the LA yield increases with a lower solid-to-liquid ratio. In contrast to previous studies, this study evaluated the reaction model in a more precise way using combination of models, considering that the reaction occurs between solid and liquid. The heterogeneous reaction model, namely the shrinking core model (SCM) for cellulose conversion to glucose and the first-order homogeneous reaction model for glucose to LA reaction, give good fitting results. The more appropriate reaction model is expected to be the basis of scale-up process carried out for industry one day. The results of this research have the potential to be applied for various other biomass raw materials with some improvements based on their characteristics which can be studied in the future.

Production of H2 via sorption enhanced auto-thermal reforming for small scale Applications-A process modeling and machine learning study

Small scale production of H2 via sorption enhanced auto-thermal reforming (SEATR) of methane is simulated using Ni based catalyst and CaO sorbent for the capturing of CO2. One dimensional heterogeneous reactor model was developed using gPROMS model builder to study the performance of SEATR reactor. At low pressure mode, the process was evaluated for varying temperature, pressure, gas flux and steam to carbon ratio. Chemical equilibrium with application (CEA), an equilibrium based software was employed so as to compare both equilibrium and simulation results. Under a range of temperature (500–1000 K), pressure (1–10 bar), S/C ratio (1–6), and O/C ratio (0.2–0.6) close to equilibrium conditions, model outputs satisfactory results with regard to CH4 conversion, CO2 capturing, H2 yield and purity. At 750 K, 2.9 bar, Gs of 0.4 kg/m2 s, S/C of 3 and O/C of 0.45, H2 purity and CH4 conversion achieved was 97% and 94% respectively in comparison with 66% and 77% from conventional auto-thermal reforming. In Bayesian Regularization (BR), Mean square error(MSE) and R value is minimum for neural network algorithm comparison. It accounts for 1.2e−10 and 0.999 respectively. BR produces minimum error with increase in Epochs and gradients values highlighting maximum performance with optimize computation time for process modeling data-integration studies and generalization.

Multi-objective optimization of adiabatic styrene reactors using Generalized Differential Evolution 3 (GDE3)

In this study, industrial styrene reactors were optimized using the multi-objective algorithm Generalized Differential Evolution 3 (GDE3) to maximize their conversion and selectivity. When modeling the reactors, an intrinsic heterogeneous reaction model was adopted to produce realistic results, which would adequately encompass the complex influence of the decision variables in the system. Several optimal scenarios were obtained using two- and three-objective approaches, which can be used in integrated process analysis to define suitable operational conditions. These scenarios were studied from a fundamental perspective to explore the impact of the steam-to-ethylbenzene molar feed ratio, the number of catalyst beds, catalyst loading, operating pressure, and inlet temperatures on reactor performance. Furthermore, our GDE3 implementation has been made available in a public code repository and a Python package.

Sensitivity of flame structure and flame speed in numerical simulations of laminar aluminum dust counterflow flames

Aluminum dust counterflow flames are investigated numerically using a two-stage model including the effects of interphase heat transfer, phase change, heterogeneous surface reaction (HSR), oxide cap growth, homogeneous combustion and radiation. The numerical model is first validated by simulating the aluminum dust counterflow flames of McGill University [Julien et al., 2017]. The results show that the particle velocity profile is consistent with the experimental results, and the error in the gas phase velocity caused by the use of aluminum particles as tracers in the experiment is analyzed. Then, further validation is conducted by comparison of the flame speed, and the predicted results agree well with the measurements. The flame structure of the aluminum dust counterflow flame is analyzed, and intermediate product (AlO) is observed to present a discrete distribution in space due to the nature of heterogeneous combustion. Different terms in the particle energy equation are analyzed, and the results indicate that the HSR plays an important role in the late preheating stage, while the interphase heat transfer dominates the rest of the conversion process. Under the assumption of unity Lewis number, the interphase heat/mass transfer models are found to have a great impact on the flame for a particle size smaller than 10 µm. With increasing particle sizes, the flame speed decreases, and most particles with a diameter of 12 µm cannot be fully burnt in the flame under the studied conditions. The effect of the strain rate on the flames is investigated with different particle sizes and unstretched reference flame speeds are obtained by linear extrapolation of the predicted results. Finally, a sensitivity analysis of the parameters of the heterogeneous surface reaction model is conducted.

Lattice Boltzmann modelling on pore-scale reactive transport in exothermic reactions of solid blocks for thermochemical energy storage

In this study, a pore-scale numerical model of plate-type reactor is developed to simulate and analyze the coupled CaO/Ca(OH)2 thermochemical heat storage processes based on the lattice Boltzmann method. In the research, the fluid flow, chemical adsorption, mass and heat transfer during hydration reaction are considered. Three different structures with the same porosity of solid particles are designed: in-line, staggered and random patterns. The heterogeneous reaction model with the Langmuir adsorption kinetics is implemented on gas–solid interfaces. The interparticle and intraparticle mass transfer processes are both involved with the help of the lattice Boltzmann method. The distributions of concentration in the gas phase and adsorbed amount in the solid phase are obtained in detail. The conversion rates under three different structures with similar porosity are also compared. Moreover, conjugate heat transfer is applied to simulate the transient temperature distributions in these structures. Heat is released from the solid particles and diffuse to the surrounding area along with the fluid flow. The maximum temperatures of the three structures are 550℃. Besides, the trends of characteristic temperatures over time are also obtained, and the durations above 500℃ are calculated, reflecting the heat storage performances of the different structures. The heat release of three different structures is also compared. It is proved that the structure with staggered blocks is recommended.

CFD Analysis of Co-firing of Coke and Biomass in a Parallel Flow Regenerative Lime Kiln

The lime industry is a highly energy intensive industry, with a huge presence worldwide. To reduce both production costs and pollutants emissions, some lime production plants are introducing more environmentally-friendly energy sources, such as local agro-industry residues. In this paper, a numerical tool is presented, which simulates a large-scale Parallel Flow Regenerative (PFR) kiln that currently uses coke as main fuel. The developed tool aims at investigating the combustion process under conditions of co-firing of coke and biomass and to assist the plant operators in the optimization of such operating conditions. To achieve this goal, a two-way coupling Euler–Lagrange approach is used to model the dynamics of the particulate phase and their interaction with the gas phase. Pyrolysis, volatiles oxidation and char oxidation are modelled by kinetics/diffusion-limited model (for heterogeneous reactions) and mixture fraction approach (for homogeneous reactions). Moreover, two methods are investigated for representing the limestone bed: a porous medium (PM) approach and a “solid blocks” (BM) tridimensional mesh. Comparison of the results for the case of 100% coke showed that the ideal “blocks” method is more accurate as it adequately simulates the scattering of fuel particles through the PFR kiln anchor, which is limited with the PM approach. Moreover, the temperature profile, maximum and minimum temperatures, as well as CO2 and O2 concentrations at outlet, are comprised in the expected range for this technology, according to available literature. Finally, the predicted results of a co-firing case with 60% biomass (in mass) were validated with measurements in an industrial facility, with production capacity of 440 calcium oxide tons per day. The results suggest that the model is fairly accurate to predict gas temperature, as well as O2 and NOX concentrations at the kiln outlet. Although some improvements are recommended to refine the CFD predictions, these promising results and the high computational efficiency laid the foundation for future modelling of co-firing of coke and biomass, as well as the modelling of the lime calcination process. It also paves the way for facilitating the reduction of pollutant emissions thus contributing to a more sustainable lime production.Graphical

OpenFOAM solver for thermal and chemical conversion in porous media

We present the porousGasificationFoam solver and libraries, developed in the open-source C++ code OpenFOAM, for the comprehensive simulation of the thermochemical conversion in porous media.The code porousGasificationFoam integrates gas flow through a porous media with the models of heterogeneous (drying, gasification, pyrolysis, solid combustion, precipitation) and homogeneous (gas combustion) chemical reactions. Inside porous media transport equations are formulated applying the spatial averaging methodology. The mass and enthalpy transfer between solid and gas phases is suitable for systems out of the thermal equilibrium. The convection and radiation modes of the heat transfer are included for gas and solid phases, and the immersed boundary technique is applied for the porous media inside the computational domain.We validate the elements of the model against a set of experimental and theoretical results. Amongst them, Thermogravimetric Analysis experiments of thermal conversions of two wooden particles: one of millimeter size the other of centimeter size. Simulations feature reaction schemes and physical parameters established in the literature. We show the influence of the porous media size on the gasification process. The millimeter particle remains uniform, while for the centimeter setup, the pyrolysis front is reproduced. The spatial patterns in physical conditions modify the course of chemical reactions and influence media composition and structure evolution. Another important example is a gasifier where we obtain a self-sustaining front propagation because of an exothermic heterogeneous reaction. Program summaryProgram Title: porousGasificationFoamCPC Library link to program files:https://doi.org/10.17632/s6sj9kgp69.1Developer's repository link:https://github.com/pjzuk/porousGasificationFoam (foam-extend-4.1); https://github.com/btuznik/porousGasificationFoam (OpenFOAM 8)Licensing provisions: GNU General Public Licence version 3Programming language: C++External routines/libraries: OpenFOAM 8, foam-extend-4.1Nature of problem: The developed software is a solver and a set of libraries for simulating the thermal conversion in porous media, including drying, pyrolysis, gasification, and combustion. The model includes the flow of the reactive gas mixture and the transfer of mass and enthalpy between the gas and solid phases. The porous medium can change during the process. The model is transient and enables three-dimensional simulations.Solution method:: The finite-volume method is used in the code for equation discretization. A set of governing equations is solved for the gas and solid phases, including mass conservation of gas species and solid components, momentum conservation in the gas phase, and equations of enthalpy conservation in both phases. The porous media region inside the whole computational domain is defined using the immersed boundary approach.

Dehydration of 2,3-Butanediol to 1,3-Butadiene and Methyl Ethyl Ketone: Modeling, Numerical Analysis and Validation Using Pilot-Scale Reactor Data

This work presents the numerical analysis and validation of a fixed bed reactor model for 2,3-butanediol (2,3-BDO) dehydration. The 1D heterogeneous reactor model considering interfacial and intra-particle gradients, was simulated and numerical analysis of the model was conducted to understand the characteristics of the reactions in a catalyst along the reactor length. The model was also validated by comparing predicted performance data with pilot-scale plant data operated at 0.2 bar, 299–343 °C and 0.48–2.02 h−1 of weight hourly space velocity (WHSV). The model showed good agreement with the temperature profile, 2,3-BDO conversion and selectivity of target products. In addition, sensitivity analyses of the model were investigated by changing feed flow rate, feed composition, and inlet temperature. It was found that stable and efficient operation conditions are lower than 0.65 h−1 of WHSV and 330–340 °C of inlet temperature. Additionally, the reactor performance was not affected by 2,3-BDO feed concentration above 70%.

Clean and stable conversion of oxygen-bearing low-concentration coal mine gas by solid oxide fuel cells with an additional reforming layer

Direct power generation using low-concentration coal mine gas (LC-CMG, < 30% CH4) by solid oxide fuel cells (SOFCs) is an attractive approach for the clean and efficient utilization of abundant LC-CMG resources. In this study, Ni–Fe alloy catalyst from in situ decomposition of NiFe2O4 oxide is used to promote the electrochemical performance, efficiency and robustness of SOFCs using simulated LC-CMG as fuel. The modified SOFC is fed with humidified H2 and CH4–N2 in sequence and exhibits high electrochemical performance. There is only a slight performance drop from 783 to 660 mW cm−2 when adding O2 in humidified CH4–N2 fuel. The operation of all cells with different concentrations of LC-CMG is quite stable during over 100-h tests and no coking is found on the entire anode and Ni–Fe alloy catalyst, suggesting the cell with superior resistance to coking. Besides, a heterogeneous reaction model is established to reveal the anti-carbon effect of the Ni–Fe catalyst. Our findings indicate the great application potential of direct power generation from LC-CMG by SOFCs with an additional reforming layer.