Methanation of CO on Ru/graphitized-carbon catalysts: Effects of the preparation method and the carbon support structure

Two kinds of Ru/C catalysts prepared by two different methods and supported on two graphitized carbons differing in their surface area were studied in CO methanation in the H₂-rich gas. The textural parameters of the support materials were characterized by means of N₂ physisorption. XRPD, XPS, TEM and CO- chemisorption studies indicate that the application of wet impregnation leads to more homogeneous composition of the Ru/carbon system and higher Ru dispersion than dry impregnation for both supports. The activity of the Ru/carbon samples in CO methanation in a H₂-rich gas stream depends on the structure and average size of the active phase crystallites. The combination of wet impregnation and the use of graphitized carbon of appropriate structure in the preparation of the Ru/C catalyst lead to a complete conversion of CO at 240 °C.     

Complete removal of carbon monoxide in hydrogen-rich gas stream through methanation over supported metal catalysts

Complete removal of CO by methanation in H₂-rich gas stream was performed over different metal catalysts. Ni/ZrO₂ and Ru/TiO₂ were the most effective catalysts for complete removal of CO through the methanation. These catalysts can decrease a concentration of CO from 0.5% to $\text{20}\text{ppm}$ in the gases formed by the steam reforming of methane with a significantly low conversion of CO₂ into methane. Catalytic activities of supported Ni and Ru strongly depended on the type of supports, i.e. ZrO₂ for Ni and TiO₂ for Ru are suitable supports for the methanation of CO. The effect of catalytic supports on methanation of CO could be explained by particles sizes of Ni and Ru metal. Catalytic activity of supported Ru catalysts for the complete removal of CO through methanation became higher as particle sizes of Ru metal became smaller, while Ni metal particles with relatively larger diameters were effective for the reaction.     

Promoted Ni–Co–Al2O3 nanostructured catalysts for CO2 methanation

15 wt.%Ni-12.5 wt.%Co–Al₂O₃ catalysts promoted with Fe, Mn, Cu, Zr, La, Ce, and Ba were prepared by a novel solid-state synthesis method and employed in CO₂ methanation reaction. BET, XRD, EDS, SEM, TPR, TGA, and FTIR analyses were conducted to identify the chemicophysical characteristics of the prepared samples. The addition of Fe, Mn, La, Ce, and Ba was effective to improve the catalytic performance of the 15 wt%Ni-12.5 wt%Co–Al₂O₃ due to the higher CO₂ adsorption capacity of the promoted catalysts. Among the studied promoters, the Fe-promoted catalyst possessed the highest catalytic activity (X_CO2 = 61.2% and S_CH4 = 98.87% at 300 °C). Also, the effect of calcination temperature, feed composition, and GHSV on the performance of the 15 wt%Ni-12.5 wt%Co-5wt%Fe–Al₂O₃ catalyst in CO₂ methanation reaction was assessed. The outcomes confirmed that the 15 wt%Ni-12.5 wt%Co-5wt%Fe–Al₂O₃ catalyst with the BET area of 122.4 m²/g and the highest pore volume and largest pore diameter had the highest catalytic activity. Also, the catalytic performance in the methanation of carbon monoxide was studied, and 100% conversion of carbon monoxide was observed at 250 °C.     

Experimental optimization analysis on operating conditions of CO removal process from hydrogen-rich reformate

The catalytic effects of CO preferential oxidation and methanation catalysts for deep CO removal under different operating conditions (temperature, space velocity, water content, etc.) are systematically studied from the aspects of CO content, CO selectivity, and hydrogen loss index. Results indicate that the 3 wt% Ru/Al₂O₃ preferential oxidation catalysts reduce CO content to below 10 ppm with a high hydrogen consumption of 11.6–15.7%. And methanation catalysts with 0.7 wt% Ru/Al₂O₃ also exhibit excellent CO removal performance at 220–240 °C without hydrogen loss. Besides, NiCl_x/CeO₂ methanation catalysts possess the characteristics of high space velocity, high activity, and high water-gas resistance, and can maintain the CO content at close to 20 ppm. Based on these experimental results, the coupling scheme of combining NiCl_x/CeO₂ methanation catalysts (low cost and high reaction space velocity) with 0.7 wt% Ru/Al₂O₃ methanation catalysts (high activity) to reduce CO content to below10 ppm is proposed.     

Solid-state synthesis method for the preparation of cobalt doped Ni–Al2O3 mesoporous catalysts for CO2 methanation

In this study, a simple solid-state synthesis method was employed for the preparation of the Ni–Co–Al₂O₃ catalysts with various Co loadings, and the prepared catalysts were used in CO₂ methanation reaction. The results demonstrated that the incorporation of cobalt in nickel-based catalysts enhanced the activity of the catalyst. The results showed that the 15 wt%Ni-12.5 wt%Co–Al₂O₃ sample with a specific surface area of 129.96 m²/g possessed the highest catalytic performance in CO₂ methanation (76.2% CO₂ conversion and 96.39% CH₄ selectivity at 400 °C) and this catalyst presented high stability over 10 h time-on-stream. Also, CO methanation was investigated and the results showed a complete CO conversion at 300 °C.     

Preferential CO oxidation on Ru/Al2O3 catalyst: An investigation by considering the simultaneously involved methanation

The CO removal with preferential CO oxidation (PROX) over an industrial 0.5% Ru/Al₂O₃ catalyst from simulated reformates was examined and evaluated through considering its simultaneously involved oxidation and methanation reactions. It was found that the CO removal was fully due to the preferential oxidation of CO until 383 K. Over this temperature, the simultaneous CO methanation was started to make a contribution, which compensated for the decrease in the removal due to the decreased selectivity of PROX at higher temperatures. This consequently kept the effluent CO content as well as the overall selectivity estimated as the ratio of the removed CO amount over the sum of the consumed O₂ and formed CH₄ amounts from apparently increasing with raising reaction temperature from 383 to 443 K when the CO₂ methanation was yet not fully started. At these temperatures the tested catalyst enabled the initial CO content of up to 1.0 vol.% to be removed to several tens of ppm at an overall selectivity of about 0.4 from simulated reformates containing 70 vol.% H₂, 30 vol.% CO₂ and with steam of up to 0.45 (volume) of dry gas. Varying space velocity in less than 9000 h⁻¹ did not much change the stated overall selectivity. From the viewpoint of CO removal the article thus concluded that the methanation activity of the tested Ru/Al₂O₃ greatly extended its working temperatures for PROX, demonstrating actually a feasible way to formulate PROX catalysts that enable broad windows of suitable working temperatures.     

Mesoporous zirconia-modified clays supported nickel catalysts for CO and CO2 methanation

The Ni catalysts supported on a new structure with zirconia nanoparticles highly dispersed on the partly damaged clay layers has been prepared by the incipient wetness impregnation method and the new structure of the support has been prepared in one pot by the hydrothermal treatment of the mixture of the clay suspension and the ZrO(NO₃)₂ solution. The catalytic performances for the CO and CO₂ methanation on the catalysts have been investigated at a temperature range from 300 °C to 500 °C at atmospheric pressure. The catalysts and supports have been characterized by X-ray diffraction (XRD), transmittance electron microscopy (TEM), H₂ temperature-programmed reduction (H₂-TPR), nitrogen adsorption–desorption, and thermogravimetry and differential thermal analysis (TG-DTA). It is found that the zirconia-modified clays have the typical bimodal pore size distribution. Most of the pores with the sizes smaller than 10 nm are resulted from the zirconia pillared clays and the mesopores with the sizes larger than 10 nm and the macropores with the sizes larger than 50 nm are resulted from the partly damaged clay layers. The bimodal pore structure is beneficial to the dispersion of Ni on the layers of the zirconia-modified clays and the increase in Ni loading. The zirconia nanoparticles are highly dispersed on the partly damaged clay layers. Nickel oxide in cubic phase is the only Ni species that can be detected by XRD. The nickel oxide nanoparticles with the sizes of 12 nanometers or more are well dispersed on the zirconia-modified clay layers, which are observed to be buried in the stack layers of zirconia. The presence of nickel oxide in six different forms could be perceived on the new structure. Five of them except the Ni species that forms the spinel phase with Al in clays can be reduced to the active Ni species for the CO and CO₂ methanation. But the activity of the Ni species is different, which is associated with the chemical environment at which the Ni species is located. The catalyst with the higher zirconia content, which also has the larger specific surface area and pore volume, exhibits the better catalytic performance for the CO or CO₂ methanation. Zirconia in the catalyst is responsible for the dispersion of the Ni species, and it prevents the metallic Ni nanoparticles from sintering during the process of the reaction. In addition, it is also responsible for the reduction of the inactive carbon deposition. The catalyst with 15 wt.% zirconia content has the highest CO conversion of about 100% and the highest methane selectivity of about 93% at 450 °C for CO methanation, and the catalyst with 20% zirconia content has the CO₂ conversion of about 80% and the highest methane selectivity of about 99% for CO₂ methanation at 350 °C. The catalyst with 15 wt.% zirconia possesses promising stability and no distinct deactivation could be perceived after reaction for 40 h. This new catalyst has great potential to be used in the conversion of the blast furnace gas (BFG) and the coke oven gas (COG) to methane.     

Unsupported cobalt nanoparticles as catalysts: Effect of preparation method on catalytic activity in CO2 methanation and ethanol steam reforming

Cobalt nanoparticles (10–50 nm) have been prepared by different procedures. Materials produced by reduction of cobalt chloride and nitrate by NaBH₄ contain B impurities as borates or borides. They are very active in ethanol steam reforming at 673–773 K with up to 85% hydrogen yield at 773 K. B-free samples obtained by thermal decomposition of Co₂(CO)₈ is slightly less selective to hydrogen, due to its activity in ethanol cracking to methane which is probably poisoned by boron impurities on the other catalysts. B-containing samples are inactive in CO₂ methanation and have weak activity in the reverse water gas shift (RWGS) reaction to CO. B-free nanoparticles have high activity in both CO₂ methanation and RWGS. However, methanation activity is reduced fast by growth of encapsulating carbon species. These particles however also show quite stable activity in RWGS to CO, attributed to CoO impurities.     

Preferential oxidation of CO in a H2-rich stream over multi-walled carbon nanotubes confined Ru catalysts

Multi-walled carbon nanotubes (MWNTs) confined Ru catalysts were prepared by a modified procedure using ultrasonication-aided capillarity action to deposit Ru nanoparticles onto MWNTs inner surface. The structure properties of MWNTs supports and Ru catalysts were extensively characterized by XRD, TGA, H₂-TPR, XPS, TEM, FTIR and Raman spectra. The catalytic performance in the preferential oxidation of CO in a H₂-rich stream was examined in detail with respect to the influences of Ru loading, MWNTs diameter, various pretreatment conditions, and the presence of CO₂ and H₂O in the feed stream. In contrast with Ru catalysts supported on MWNTs external surface and other carbon materials, the superior activity was observed for the MWNTs-confined Ru catalyst, which was discussed intensively in terms of the confinement effect of carbon nanotubes. The optimized catalyst of 5 wt.% Ru confined in MWNTs with diameter of 8–15 nm can achieve the complete CO conversion in the wider temperature range and the favorable stability at 80 °C under the simulated reformatted gas mixture, which proves a promising catalyst for preferential CO oxidation in H₂-rich stream.     

Highly stable Ni-based catalysts derived from LDHs supported on zeolite for CO2 methanation

CO₂ methanation can effectively reduce the concentration of CO₂ in the air and decrease environmental pollution. Therefore, it is essential to synthesize catalysts with high carbon deposition resistance and stability. Herein, the highly stabilized Ni-based catalysts derived from hydrotalcites are prepared by the self-sacrificial template method and used for CO₂ methanation. The prepared Ni-based catalysts maintain the morphology of the hydrotalcites precursors and the Ni particles are embedded in the AlO_x substrate. The catalyst show high performance at 350 °C, 0.1 MPa and a high space velocity of 30,000 mL g⁻¹ h⁻¹, with the conversion rate of CO₂ and selectivity of CH₄ reaching 87.5% and 100%, respectively. More importantly, the activity of catalyst does not decrease after continuous reaction for 200 h at 350 °C with different space velocities (30,000 and 60,000 mL g⁻¹ h⁻¹) owing to the confinement of the AlO_x substrate, which suppress the undesirable agglomeration and sintering of the Ni particles. This unique mosaic structure has certain reference significance for studying materials with excellent stability at high temperatures.     

Impact of mesoporous structure of acid-treated clay on nickel dispersion and carbon deposition for CO methanation

Nickel catalysts supported on different acid-treated clays were prepared by the impregnation method in order to investigate the effect of the pore structures of supports on the dispersion and the chemical states of nickel species, and thus on the carbon depositions resulted from the dissociation of the CO molecules adsorbed on different active nickel sites. The catalysts and supports were characterized by the X-ray diffraction (XRD), the transmittance electron microscopy (TEM), the H₂ temperature-programmed reduction (H₂-TPR), the nitrogen adsorption–desorption, and the thermogravimetry and differential thermal analysis (TG-DTA). The CO methanation performance of the catalyst was investigated at a temperature range from 300 °C to 500 °C. The results indicated that the dispersion and the states of the nickel species on the support were influenced strongly by the pore structures of the acid-treated clays, and only the mesopores composed by partly damaged clay layers were conducive to forming the active nickel species, and thus reducing the deposition of the inactive carbon and improving the stability of the catalyst. The carbon species deposited on different active sites was slightly different in the oxidative properties when it was oxidized in air. A fraction of aluminum in the clays was leached out by acid, which decreased the possibility of forming the spinel phase of nickel aluminate in the catalyst. The highly dispersed nickel species showed little relevance to the high activity of the catalyst, but it exhibited a strong relation to the nickel sites from the bulk nickel species.     

Highly efficient Ru/TiO2‐NiAl mixed oxide catalysts for CO selective methanation in hydrogen‐rich gas

Selective CO methanation (CO‐SMET) is viewed as an effective H₂‐rich gas purification technique for proton exchange membrane fuel cells. In this work, improved composite‐supported Ru catalysts were developed for the CO‐SMET process. Mixed metal oxides (MMOs) obtained by calcination of layered double hydroxides precursor were used as an effective catalyst supports. After incorporation of TiO₂, the resulting TiO₂‐MMO composites were expected to have an enhanced catalytic performance. Therefore, a series of TiO₂‐NiAl layered double hydroxides was successfully prepared via 1‐pot deposition method. After calcination, the derived TiO₂‐NiAl MMO‐supported Ru catalysts obtained by impregnation method showed excellent catalytic performance for CO‐SMET reaction. The catalyst could deeply remove the CO outlet concentration (<10 ppm) with a high selectivity (>50%) over the wide low‐temperature window (175‐260°C). Furthermore, the catalyst also showed high stability with no deactivation during a long‐term durability test (120 h). Based on X‐ray diffraction, Fourier transform infrared, Raman, thermogravimetric differential scanning calorimetry, N₂ adsorption‐desorption, temperature‐programmed reduction, scanning electron microscopy, and transmission electron microscopy analyses, the enhanced catalytic performance of the TiO2‐NiAl MMO‐supported Ru catalyst was found to be related to the higher dispersion of Ru nanoparticles, partially reduced NiO species, and the increased specific surface area and structural stability of the support. The facile synthesis strategy proposed herein may open a new window for the efficient production of high‐quality H₂.     

A study of the methanation of carbon dioxide on Ni/Al2O3 catalysts at atmospheric pressure

The hydrogenation of carbon dioxide producing methane and CO has been investigated over Ni/Al₂O₃ catalysts. The as prepared catalysts have been characterized by XRD and Temperature Programmed Reduction. Spent catalysts have been characterized by XRD and Field Emission SEM. Catalytic activity needs the presence of Ni metal particles which may form in situ if the Ni loading is higher than that needed to cover the alumina surface with a complete monolayer. If Ni content is lower, pre-reduction is needed. Catalysts containing very small Ni particles obtained by reducing moderate loading materials are very selective to methane without CO formation. The larger the Ni particles, due to higher Ni loadings, the higher the CO production. Cubic Ni metal particles are found in the spent catalysts mostly without carbon whiskers. The data suggest that fast methanation occurs at the expense of CO intermediate on the corners of nanoparticles interacting with alumina, likely with a “via oxygenate” mechanism.     

Effect of noble metal addition over active Ru/TiO2 catalyst for CO selective methanation from H2 rich-streams

Selective CO methanation from H₂-rich stream has been regarded as a promising route for deep removal of low CO concentration and catalytic hydrogen purification processes. This work is focused on the development of more efficient catalysts applied in practical conditions. For this purpose, we prepared a series of catalysts based on Ru supported over titania and promoted with small amounts of Rh and Pt. Characterization details revealed that Rh and Pt modify the electronic properties of Ru. The results of catalytic activity showed that Pt has a negative effect since it promotes the reverse water gas shift reaction decreasing the selectivity of methanation but Rh increases remarkably the activity and selectivity of CO methanation. The obtained results suggest that RuRh-based catalyst could become important for the treatment of industrial-volume streams.     

Design and test of a miniature hydrogen production reactor integrated with heat supply,fuel vaporization,methanol-steam reforming and carbon monoxide removal unit

This study presents a designed and tested integrated miniature tubular quartz-made reactor for hydrogen (H₂) production. This reactor is composed of two concentric tubes with an overall length of 60 mm and a diameter of 17 mm. The inner tube was designed as the combustor using Pt/Al₂O₃ as the catalyst. The gap between the inner and outer tubes is divided into three sections: a liquid methanol-water vaporizer, a methanol-steam reformer using RP-60 as the catalyst and a carbon monoxide (CO) methanator using Ru/Al₂O₃ as the catalyst. The experimental measurements indicated that this integrated reactor works properly as designed. The methanol conversion, hydrogen production rate and CO concentration were found to increase with an increasing methanol/air flow rate in the combustor and decreases with an increasing methanol/water feed rate to the reformer. The methanator experimental results indicated that the CO conversion and H₂ consumption can be enhanced by increasing the Ru loading. It was also found that the CO methanation depends greatly on the reaction temperature. With a higher reaction temperature, the CO methanation, carbon dioxide (CO₂) methanation, and reversed water gas shift reactions took place simultaneously. CO conversion was found to decrease while H₂ consumption was found to increase. At a lower reaction temperature both the CO conversion and H₂ consumption were found to increase indicating that only CO methanation took place. From the experimental results the maximum methanol conversion, hydrogen yield, and CO conversion achieved were 97%, 2.38, and 70%, respectively. The actual lowest CO concentration and maximum power density based on the reactor volume were 90 ppm and 0.8 kW/L, respectively.     

Effect of Ni content on CO2 methanation performance with tubular-structured Ni-YSZ catalysts and optimization of catalytic activity for temperature management in the reactor

This paper presents high-performance Ni-YSZ tubular catalysts for CO₂ methanation prepared by the extrusion molding. We fabricated tubular-shaped Ni-YSZ catalysts with various Ni contents (25–100 wt% NiO) and investigated the effect of Ni content on CO₂ methanation performance under various temperatures and gas flow rates. Catalysts with Ni contents >75 wt% showed CH₄ yields >91% above 270 °C with high CH₄ selectivities (>99%). High CH₄ yields were also observed under high GHSVs at 300 °C: 93% and 92% at 8700 and 17,500 h⁻¹, respectively. Investigation of methanation with the catalysts revealed that CO₂ methanation was accelerated by a localized hotspot at the reactor inlet arising from the interaction between reaction kinetics and heat generation. Using a numerical simulation, we considered the optimum arrangement of catalytic activity in the reactor to avoid hotspot generation and realize a stable high CO₂ methanation performance. We can simultaneously achieve high CH₄ production and prevent hotspot formation by properly arranging catalysts with different activities.     

The optimization of Ni–Al2O3 catalyst with the addition of La2O3 for CO2–CH4 reforming to produce syngas

A series of La₂O₃–NiO–Al₂O₃ catalysts promoted by different loading of lanthanum were prepared via the hydrolysis-deposition method to improve the catalytic performance of nickel-based catalyst for CO₂–CH₄ reforming. The catalysts were characterized by N₂ adsorption - desorption, XRD, H₂-TPR, TG-DTG, TEM, Raman and TPH techniques. Results showed that the precursor of active component was mainly in the form of NiAl₂O₄ spinel, which almost disappeared after reduction process from XRD characterization, suggesting well reduction performance. The catalyst with La loading of 0.95 wt% (La–Ni-1) presented a small average Ni grain size of 7.71 nm and exhibited well catalytic performance at 800 °C, with CH₄ conversion of 94.37%, CO₂ conversion of 97.15%, H₂ selectivity of 75.01% and H₂/CO ratio of 0.92. The Ni grain size of La–Ni-1 increased only 5.84% to 8.16 nm after performance test, which was lower than that of others and indicated a well structure stability. Additionally, the strong carbon diffraction peak over La–Ni-0.5 and La–Ni-2 catalysts suggested the presence of crystalline carbon species accumulated on the catalysts, while there was no carbon peak over La–Ni-1 sample. A 150 h stability test for La–Ni-1 demonstrated that the conversion of CH₄ was around 95%, higher than that of La–Ni-0 (without lanthanum addition) and La–Ni-4 (with La content of 3.82 wt%). The carbon deposition rate of La–Ni-1 was only 1.63 mg/(g_cat·h), lower than that of La–Ni-4 (2.20 mg/(g_cat·h)), showing both high activity and well stability. Therefore, the “confinement effect” of La₂O₃ to Ni crystalline grain would inhibit the sintering of active component, prevent the carbon deposition, and improve the catalytic reforming performance.     

Nickel on a macro-mesoporous Al2O3@ZrO2 core/shell nanocomposite as a novel catalyst for CO methanation

A novel nickel catalyst supported on Al₂O₃@ZrO₂ core/shell nanocomposites was prepared by the impregnation method. The core/shell nanocomposites were synthesized by depositing zirconium species on boehmite nanofibres. This contribution aims to study the effects of the pore structure of supports and the zirconia dispersed on the surface of the alumina nanofibres on the CO methanation. The catalysts and supports were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), H₂ temperature-programmed reduction (H₂-TPR), nitrogen adsorption–desorption, and thermogravimetry and differential thermal analysis (TG-DTA). The catalytic performance of the catalysts for CO methanation was investigated at a temperature range from 300 °C to 500 °C. The results of the characterization indicate that the metastable tetragonal zirconia could be stably and evenly dispersed on the surface of alumina nanofibres. The interlaced nanorods of the Al₂O₃@ZrO₂ core/shell nanocomposites resulted in a macropore structure and the spaces between the zirconia nanoparticles dispersed on the alumina nanofibres formed most of the mesopores. Zirconia on the surface of the support promoted the dispersion and influenced the reduction states of the nickel species on the support, so it prevented the nickel species from sintering as well as from forming a spinel phase with alumina at high temperatures, and thus reduced the carbon deposition during the reaction. With the increase of the zirconia content in the catalyst, the catalytic performance for the CO methanation was enhanced. The Ni/Al₂O₃@ZrO₂-15 exhibited the highest CO conversion and methane selectivity at 400 °C, but they decreased dramatically above or below 400 °C due to the temperature sensitivity of the catalyst. Ni/Al₂O₃@ZrO₂-30 exhibited a high and constant rate of methane formation between 350 °C and 450 °C. The excellent catalytic performance of this catalyst is attributed to its reasonable pore structure and good dispersion of zirconia on the support. This catalyst has great potential to be further studied for the future industrial use.     

Coal char supported Ni catalysts prepared for CO2 methanation by hydrogenation

Catalytic CO₂ methanation is a potential solution for conversion of CO₂ into valuable products, and the catalyst plays a crucial role on the CO₂ conversion and CH₄ selectivity. However, some details involved in the CO₂ methanation over the carbon supported Ni catalysts are not yet fully understood. In this work, commercial coal char (CC) supported Ni catalysts were designed and prepared by two different methods (impregnation-thermal treatment method and thermal treatment-impregnation method) for CO₂ methanation. Effects of the preparation conditions (including the thermal treatment temperature and time, the mass ratio of CC:Ni and the preparation method), as well as the reaction temperature of CO₂ methanation, were investigated on the catalyst morphology, reducibility, structure and catalytic performance. Fibrous Ni-CC catalyst is achieved and shows high CO₂ conversion (72.9%–100%) and CH₄ selectivity (>99.0%) during the 600-min methanation process. Adverse changes of the catalyst surface and textural properties, reducibility, particle size and morphology are the potential factors leading to the catalyst deactivation, and possible solutions resistant to the deactivation were analyzed and discussed. The CO₂ methanation mechanism with the CO route was proposed based on the oxidation-reduction cycle of Ni in this work.     

Carbon oxides methanation in equilibrium; a thermodynamic approach

Global warming and greenhouse gases as two main threat to human societies due to increasing carbon oxides, such as CO and CO₂ and lack of energy storages results in challenges efforts to controlling these atmospheric pollutions in various ways and methods. Carbon oxides methanation was considered as chemical process to conversion carbon oxides to their products as syngas. Various parameters can be effective on this process such as temperature, pressure and equivalence ratio of feeding products specially H₂/CO₂ and H₂/CO. In this study, three various equivalence ratio of feeding products were investigated against pressure and temperature in equilibrium condition to determine concentration of main products. Five various pressures applied to system of equilibrium, i.e. 1, 5, 10, 25, 50 atm beside temperature change from 200 K to 1500 K. Moreover, fugacity effects also were investigated in Soave–Redlich–Kwong equation of state in comparison with ideal gas. Results revealed that fugacity was completely changes the results especially for water production and hydrogen consumption. According to the results, carbon di and monoxides conversion were increased during pressure increasing where methane selectivity also increased. In maximum condition of coke formation there was 0.1 mol fraction of it in both CO and CO₂ methanation. Although, higher equivalence ratio of each carbon oxides combination feeding products ascended CH₄ selectivity and yield but in high equivalence ratio (ER = 6) CH₄ yield decreased about 8% for both investigated methanation process. In lower equivalence ratio (lower than stoichiometric) condition, methane yield replaced with mainly carbon yield.