Sabatier Reaction Research Articles

Steam reforming of methane over nickel catalyst using a one-dimensional model

Steam reforming of hydrocarbons is a well established chemical process which provides synthesis gas (H2 and CO). These synthesis products can hence be converted to numerous valuable basic chemicals. For the industrial application of steam reforming, a detailed understanding of the process is a prerequisite. Models that capture the detailed homogeneous and heterogeneous reaction kinetics and the comprehensive transport processes as well as their interaction have the potential to optimize the catalytic process without expensive experimental campaigns.
 In this paper, a detailed investigation has been done using a multi-step reaction mechanism for modeling steam reforming of methane over nickel-based catalyst using a one-dimensional (1D) model, LOGEcat [1]. The model is applicable to the simulation of all standard after-treatment catalytic processes of combustion exhaust gas along with other chemical processes involving heterogeneous catalysis, such as, the Sabatier process [27]. It is a 1D tool, thus is computationally cost effective and is based on a series of perfectly stirred reactors (PSR).
 The model is used to perform the simulations for various reactor conditions in terms of temperature, pressure, flow rates and steam-to-carbon (S/C) ratio. Several chemical reaction terms, such as, selectivity, yield, conversion, and mole fraction have been shown with respect to the varied parameters and the results are compared with 2D simulations and experimental reference data. We report a very good agreement of the various profiles produced with 1D model as compared to the reference data.
 Note that the main aim of this study is to check how far the 1D model can capture the basic chemistry for modeling steam reforming of methane over nickel-based catalysts. It is interesting to note that the cost effective reduced order model is capable to capture the physics and chemistry involved with a multi-step reaction mechanism showing the predictive capability of the model. This study forms the basis for further analysis towards the thermochemistry of the species to develop a kinetically consistent reaction mechanism.

CFD simulation of the Sabatier process in a shell-and-tube reactor under local thermal non-equilibrium conditions: Parameter sensitivity and reaction mechanism analysis

The Sabatier process is a competitive technology applied for carbon capture and utilization. This process increases the risk of carbon deposition and catalyst thermal degradation because of its exothermic property. In this study, a CFD model verified through existing experimental data was established to systematically investigate the Sabatier process in a shell-and-tube reactor. The effects arising from several operating parameters (e.g., gas flow rate, feed gas composition, the thermal conductivity of catalyst pellet, the inlet temperature of cooling phase, as well as phase change refrigeration) on temperature profile and reaction performance were studied. Moreover, a mechanism of three reactions was investigated, including CO 2 methanation, CO methanation, as well as RWGS reaction. Furthermore, the competition between CO 2 methanation and RWGS reaction was explored. According to the further sensitivity analysis, increasing the thermal conductivity of the catalyst particles would be effective to inhibit hot spots, while keeping the carbon conversion rate unchanged. • A CFD model of the Sabatier process under local thermal non-equilibrium conditions. • The conjugate heat transfer among gas, catalyst bed, reactor, and cooling phase. • A mechanism of three reactions on the Sabatier process was explored. • Parameter sensitivity of operating parameters for the Sabatier process was analyzed.

Promotion of Ru or Ni on Alumina Catalysts with a Basic Metal for CO2 Hydrogenation: Effect of the Type of Metal (Na, K, Ba).

Ru and Ni on alumina catalysts have been promoted with a 10 wt% of alkali metal (K or Na) or alkaline earth metal (Ba) and tested in CO2 methanation. For the catalyst consisting of Ni and Ba, the variation of Ba loading while keeping Ni loading constant was studied. The promotion in terms of enhanced CH4 yield was found only for the addition of barium to 15 wt% Ni/Al2O3. In contrast, K and Na addition increased the selectivity to CO while decreasing conversion. For the Ru-based catalyst series, no enhancement in conversion or CH4 yield was attained by any of the alkaline metals. CO2 temperature-programed desorption (CO2-TPD) revealed that the amount of chemisorbed CO2 increased significantly after the addition of the base metal. The reactivity of COx ad-species for each catalyst was assessed by temperature-programed surface reaction (TPSR). The characterization revealed that the performance in the Sabatier reaction was a result of the interplay between the amount of chemisorbed CO2 and the reactivity of the COx ad-species, which was maximized for the (10%Ba)15%Ni/Al2O3 catalyst.

Remarkable Activity of 002 Facet of Ruthenium Nanoparticles Grown on Graphene Films on the Photocatalytic CO2 Methanation

AbstractIn the context of diminishing atmospheric CO2 emissions, there is an urgent need to develop processes that can be carried out at a scale commensurate with appropriate CO2 volumes. One possible reaction is the transformation of CO2 to methane (Sabatier reaction). Due to its chemical stability, catalytic CO2 hydrogenation to methane is carried out at temperatures of 450 °C or higher and pressures above 5 bars, thus, requiring a significant energy input. One alternative possibility to conventional thermal catalysis is the use of solar light as the primary energy, performing the photocatalytic CO2 hydrogenation. In this broad context, the present study shows the photocatalytic activity of nanometric films of oriented Ru nanoparticles (NPs) strongly grafted on defective graphene. These graphene films (thinner than 20 nm) containing Ru NPs nanoplatelets (less than 2 nanomolRu/cm2) are among the most active photocatalysts ever prepared for CO2 hydrogenation and operate through photoinduced charge separation.

Comparing the Performance of Supported Ru Nanocatalysts Prepared by Chemical Reduction of RuCl3 and Thermal Decomposition of Ru3(CO)12 in the Sunlight-Powered Sabatier Reaction

The preparation of Ru nanoparticles supported on γ-Al2O3 followed by chemical reduction using RuCl3 as a precursor is demonstrated, and their properties are compared to Ru nanoparticles supported on γ-Al2O3 prepared by impregnation of γ-Al2O3 with Ru3(CO)12 and subsequent thermal decomposition. The Ru nanoparticles resulting from chemical reduction of RuCl3 are slightly larger (1.2 vs. 0.8 nm). In addition, Ru nanoparticles were deposited on Stöber SiO2 using both deposition techniques. These particles were larger than the ones deposited on γ-Al2O3 (2.5 and 3.4 nm for chemical reduction and thermal decomposition, respectively). Taking into account the size differences between the Ru nanoparticles, all catalysts display similar activity (0.14–0.63 mol·gRu−1·h−1) and selectivity (≥99%) in the sunlight-powered Sabatier reaction. Ergo, the use of toxic and volatile Ru3(CO)12 can be avoided, since catalysts prepared by chemical reduction of RuCl3 display similar catalytic performance.

Reversible electrodes based on B-site substituted Ba0.5Sr0.5Co0.8Fe0.2O3-δ for intermediate temperature solid-oxide cells

The Ba0.5Sr0.5Co0.8Fe0.2O3-δ perovskite is a promising electrode material for solid-oxide electrochemical cells exhibiting excellent oxygen reduction reaction (ORR) activity and mixed ionic-electronic transport properties at intermediate temperatures but suffers from stability issues. In this work, the effect on stability and electrochemical performance of several B-site substituted cations (Sc, Zr, Y) are studied. The presence of these substituted cations improved stability by preventing (a) the formation of the detrimental hexagonal phase during long term air exposure experiments and (b) reducing the formation of carbonates in CO2-containing atmospheres. Symmetrical cell testing revealed that the Sc-substituted material mixed with an ionic gadolinium-doped ceria (GDC) phase has the lowest polarization resistance among the materials and thus was chosen as the cathode for the full cell construction. The composite electrode achieved encouraging power density values ~877 mW/cm2 at 700 °C. The material showed stable hydrogen generation during intermediate temperature electrolysis tests and its performance improved upon the introduction of CO2 to carry out co-electrolysis. Furthermore, methane was obtained during co-electrolysis and Sabatier reaction at temperatures below 450 °C. The superior stability and performance of the Sc-substituted Ba0.5Sr0.5Co0.8Fe0.2O3-δ make it an exciting candidate for application as a cathode in reduced temperature electrochemical cells.

Autothermal CO2 hydrogenation reactor for renewable natural gas generation: experimental proof-of-concept

94% CO2 conversion and 100% formation selectivity to CH4 are obtained in a laboratory Sabatier reactor with a packed bed, air-cooled configuration, using a commercial Ni catalyst.

USE OF METHANE IN CLOSED-LOOP LIFE SUPPORT SYSTEMS FOR SPACE MISSIONS

The paper discusses the use of methane (generated in the process of oxygen recovery from carbon dioxide released by the crew during its hydrogenation in the Sabatier reaction, with subsequent extraction of 61% of oxygen through electrolysis of the resultant water) in a regenerative life support system for crews on space missions. It demonstrates that the methane resulting from Sabatier reaction can be used both for pyrolysis in order to return the resulting hydrogen into this reaction so as to extract 100% of oxygen from carbon dioxide, and for producing food protein for life support in space. The use of methane pyrolysis was enabled by new technologies which allowed lowering the process temperature down to 500–700°C and obtaining the easy-to-remove carbon. It provides recommendations for designing space systems for methane pyrolysis. The paper makes the case for use of the existing processes for industrial production of protein from methane using methanotrophic bacteria in the production of food protein for space food rations, determines the balance of a closed-loop methanotrophic reaction, provides calculation basis and recommendations for designing space systems for methanotrophic production of food protein. Development of a system for food protein production from methane will enable its use as one of the systems for providing food on the Moon and Mars, as well as a backup system in space transportation missions. Key words: space missions, crew life support, СО2 hydration, methane pyrolysis, methanotrophic bacteria, food protein.

Process development and performance assessment of flexible calcium looping biomass gasification for production of renewable gas with adjustable composition

In recent years, the field of biomass gasification as a method of transforming biomass into a more useable gaseous fuel experienced expedited development since it represents a prominent way to achieve sustainability goals and targets set by the Paris accord and, more recently, the European Green Deal. The use of natural gas is projected to reduce with the transition toward exploitation of renewable gas, while a new area of hydrogen applications is also emerging. However, with uncertain production of current processes, and consumption patterns seen on the market, an opportunity for a new flexible process exists. This article investigates a concept process design of sorption-enhanced gasification (SEG) based on calcium looping. Aspen Plus simulation software was used to develop and simulate the process models for flexible production of bio-SNG or bio-H2. The process parameters can be manipulated to either achieve a high-purity bio-H2 (>96 mol%) or high-purity bio-SNG (>95 mol%), as well as any other combination of the two main products. The concept process is based on a low-pressure, low-temperature dual-fluidized bed reactor with steam as a gasifying agent and an additional downstream Sabatier process reactor to achieve high CH4 contents. The simulated process achieves process efficiency of up to 62.2%LHV and 78.0%LHV for H2 and CH4 production, respectively, with production yields reaching 0.112 kg H2/kg BM and 0.23 kg CH4/kg BM. These values were validated and benchmarked against comparable process designs, and the performance of the proposed process was found to be on par or superior. Overall, the proposed process design exhibits clear benefits of calcium looping gasification, with high process efficiency, negligible NOx, SO2, and H2S content, and high flexibility. Therefore, the proposed process addressed and successfully solved some of the key challenges of achieving viability of a gasification plant on a commercial scale.

Graphite Felt-Sandwiched Ni/SiC Catalysts for the Induction Versus Joule-Heated Sabatier Reaction: Assessing the Catalyst Temperature at the Nanoscale

Graphite Felt-Sandwiched Ni/SiC Catalysts for the Induction Versus Joule-Heated Sabatier Reaction: Assessing the Catalyst Temperature at the Nanoscale

A Membrane Reactor with Microchannels for Carbon Dioxide Reduction in Extraterrestrial Space

Long-term continuous oxygen supply is of vital importance during the process of space exploration. Considering the cost and feasibility, in situ resource utilization (ISRU) may be a promising solution. The conversion of CO2 to O2 is a key point for ISRU. In addition, the utilization of the abundant CO2 resources in the atmosphere of Mars is an important topic in the field of manned deep space exploration. The Sabatier reaction, Bosch reaction, and solid oxide electrolysis (SOE) are well-known techniques for the reduction of CO2. However, all the above techniques need great energy consumption. In this article, we designed an electrochemical membrane reactor at room temperature based on microfluidic control for the reduction of CO2 in extraterrestrial space. In this system, H2O was oxidized to O2 on the anode, while CO2 was reduced to C2H4 on the cathode. The highest Faraday efficiency (FE) for C2H4 was 72.7%, with a single-pass carbon efficiency toward C2H4 (SPCE-C2H4) of 4.64%. In addition, a microfluidic control technique was adopted to overcome the influence of the microgravity environment. The study may provide a solution for the long-term continuous oxygen supply during the process of space exploration.

Intensification of catalytic CO2 methanation mediated by in-situ water removal through a high-temperature polymeric thin-film composite membrane

Catalytic CO2 methanation technology can be improved by process intensification, i.e. enabling higher energy efficiency and process sustainability. Here, thin-film composite membranes (TFCM) were developed for in-situ water removal in a catalytic membrane reactor (CMR) for the Sabatier process. The selective separation layer (1.4 μm-thick) of the composite membrane is made of the polyimide 6FDA-6FpDA, a glassy polyimide, which exhibits high permeability and selectivity together with stable function at unprecedented high temperatures (>200 °C), compared to polyimides reported until now (90 °C), thus matching the temperature range of Sabatier reactors. Remarkably, TFCM developed in this work, allow to extract an outstanding amount of water up to 1 m3/(m2·h·bar) at 260 °C. TFCM was implemented for the water removal from the methanation reaction in a CMR operated at 260 °C and using Ni-Todorokite as catalyst. The TFCM-mediated water-extraction enabled to raise both catalytic stability and activity during CMR operation. CO2 conversion stability was greatly improved exhibiting a conversion value of 72 % during the course of the reaction (21 % increase in CO2 conversion), with a water removal of 12.5 % and specific flux of ∼100 g·h−1 m−2.

Cooperative catalysis coupling photo-/photothermal effect to drive Sabatier reaction with unprecedented conversion and selectivity

•We designed a catalyst coupling photo-/photothermal effect for Sabatier reaction •The 0.35%[email protected]2V2O7 catalyst achieved a record CH4 production rate •The conversion and selectivity approached the thermodynamic equilibrium limit The development of highly efficient catalysts to drive the Sabatier reactions under mild conditions remains a great challenge. Here, we report a 0.35%[email protected]2V2O7 catalyst exhibited an unprecedented solar-driven CO2 methanation rate of 114.9 mmol gcat−1h−1 (32.8 mol gRu−1 h−1 as normalized to the mass of the Ru catalyst), which was approximately 40 and 460 times larger than the rates obtained over the bare Ni2V2O7 and [email protected]2 catalysts, respectively. Moreover, the 0.35%[email protected]2V2O7 catalyst exhibited 93.5% CO2 conversion efficiency and 99% selectivity for CH4 production, approaching the thermodynamic equilibrium limit of thermocatalytic CO2 methanation. Further investigations revealed a cooperative mechanism coupling photocatalysis and photothermal catalysis between the Ru and Ni2V2O7. When illuminated, Ru clusters acted as a “nanoheater” and raised the local temperature to activate H2 and desorb H2O molecules. The spilled H adatoms reacted with adsorbed CO2 on the surface of O-vacancy-rich Ni2V2O7 to achieve cooperative catalysis for CO2 methanation. The development of highly efficient catalysts to drive the Sabatier reactions under mild conditions remains a great challenge. Here, we report a 0.35%[email protected]2V2O7 catalyst exhibited an unprecedented solar-driven CO2 methanation rate of 114.9 mmol gcat−1h−1 (32.8 mol gRu−1 h−1 as normalized to the mass of the Ru catalyst), which was approximately 40 and 460 times larger than the rates obtained over the bare Ni2V2O7 and [email protected]2 catalysts, respectively. Moreover, the 0.35%[email protected]2V2O7 catalyst exhibited 93.5% CO2 conversion efficiency and 99% selectivity for CH4 production, approaching the thermodynamic equilibrium limit of thermocatalytic CO2 methanation. Further investigations revealed a cooperative mechanism coupling photocatalysis and photothermal catalysis between the Ru and Ni2V2O7. When illuminated, Ru clusters acted as a “nanoheater” and raised the local temperature to activate H2 and desorb H2O molecules. The spilled H adatoms reacted with adsorbed CO2 on the surface of O-vacancy-rich Ni2V2O7 to achieve cooperative catalysis for CO2 methanation.

Determination of Kinetic Parameters for CO2 Methanation (Sabatier Reaction) over Ni/ZrO2 at a Stoichiometric Feed-Gas Composition under Elevated Pressure

Methanation of CO2 using H2 obtained by renewable energy sources has been gaining attention as one of the promising options for utilizing captured CO2 and surplus power obtained when intermittent p...

Renewable natural gas as climate-neutral energy carrier?

Natural gas is a potent greenhouse gas but remains an attractive energy resource for a good number of reasons. Because complementing the use of natural gas with carbon dioxide capture and storage yields several drawbacks, producing synthetic natural gas instead could be an interesting alternative. Methanation is an established and well-known process, and with atmospheric carbon dioxide as input it could deliver a climate-neutral energy carrier, which we refer to as renewable natural gas. At present, however, methanation is exceedingly costly. In this paper we try to answer two main questions: (I) can innovative methanation such as based on sunlight-powered plasmon catalysis compete with more conventional methanation options using the Sabatier reaction in e.g. adiabatic fixed-bed processes; (II) can these two alternatives ever compete with abundantly available natural gas? Under realistic assumptions for technology learning, we find that innovative methanation technology could compete with conventional methanation systems sometime between 2032 and 2039 in our base case scenario. The required learning investments for the innovative option would amount to about 80 M€, spent on an installed capacity of around 750 MW. We also conclude that the levelized cost of methane remains dominated by the cost of hydrogen until at least the middle of the century. Methanation could in principle compete with natural gas by 2050, but only if a carbon tax is levied of at least 270 €/tCO2.

CO2 methanation in a Ni-Fe based catalyst fixed bed reactor enhanced by selective water adsorption with LTA zeolites (Sorption Enhanced Sabatier Reaction – SESaR)

A Fixed-Bed reactor improved by selective water adsorption LTA zeolites is proposed as an alternative to the conventional methanation reactors. This reactor produces methane from renewable H2 (i.e. surplus electricity) and high CO2 concentration sources, as could be municipal wastes derived biogas (30%v CO2 + 70%v CH4). As catalyst, a supported (g-Al2O3) Ni-Fe (7.5:2.5 wt/wt) was chosen.

Víctor D Mercader - CO2 methanation in a Ni-Fe based catalyst fixed bed reactor enhanced by selective water adsorption with LTA zeolites (Sorption Enhanced Sabatier Reaction) - SESaR

Víctor D Mercader - CO2 methanation in a Ni-Fe based catalyst fixed bed reactor enhanced by selective water adsorption with LTA zeolites (Sorption Enhanced Sabatier Reaction) - SESaR

Synergistic effect of MgH2 doping with Ni and carbon nanotubes on thermochemical CO2 recycling process for CH4-H2 mixtures production

The synergistic effect of the nickel and carbon nanotubes addition on thermochemical processes for CO2 recycling employing MgH2 as hydrogen source was demonstrated. By reducing the metallic charge from 10wt.% Ni, replacing 5wt.% with CNTs, the amount of produced methane through thermal treatment at ∼350–375 °C under CO2 increased more than 30%. A COx-free mixture of methane (70.9%) and hydrogen (29.1%) with a CH4 yield of 79% was obtained by reaction at 350 °C during 48 h. Ni-containing species act as selective catalyst promoting the occurrence of the Sabatier reaction, which competes with the direct reduction of CO2 to generate CH4via C as an intermediary. The role of CNTs is not catalytic but rather it could be related to the protection of the hydride. It is proposed that when MgH2 is neighbored by graphitic planes, its oxidation due to direct contact with CO2 and/or the generated H2O could be impeded or retarded.

Electrochemical Fuel Production from CO2 for Orbital Refueling and Mars Settlements

Renewable CO2 electrosynthesis is a potentially promising tool to utilize unwanted greenhouse gas on Earth. Among the commodities that have been made using CO2, H2O, and electricity, CH4 is one of the simplest and most researched products. Technoeconomic studies of CO2 methanation make it clear that its high-value applications are limited without significant subsidy on Earth, where it competes with low-cost natural gas. In space, however, CO2 methanation via the Sabatier reaction is already used on the International Space Station to recycle atomic oxygen, and propulsion systems employing cryogenic liquid methane are in development for reusable rocket engines. This talk will discuss the progress made by Air Company in developing lightweight and compact systems that produce chemical products, including CH4, and O2 for from CO2, H2O, and electricity for applications in space and on Mars.

Exploiting In-Situ Characterization for a Sabatier Reaction to Reveal Catalytic Details

In situ characterization of catalysts provides important information on the catalyst and the understanding of its activity and selectivity for a specific reaction. TPX techniques for catalyst characterization reveal the role of the support on the stabilization and dispersion of the active sites. However, these can be altered at high temperature since sintering of active species can occur as well as possible carbon deposition through the Bosch reaction, which hinders the active species and deactivates the catalyst. In situ characterization of the spent catalyst, however, may expose the causes for catalyst deactivation. For example, a simple TPO analysis on the spent catalyst may produce CO and CO2 via a reaction with O2 at high temperature and this is a strong indication that deactivation may be due to the deposition of carbon during the Sabatier reaction. Other TPX techniques such as TPR and pulse chemisorption are also valuable techniques when they are applied in situ to the fresh catalyst and then to the catalyst upon deactivation.