Thermocatalytic Decomposition Of Methane Research Articles

Highly pure hydrogen production via the thermocatalytic decomposition of methane over Ni/SiO2.MgO catalysts: Impact of the catalyst's chemical composition

The goal of current research is to focus on exploring the effects of various MgO/SiO2 ratios, emphasizing their impact on the structure properties and advancing the catalytic activity and the chemical life span of Ni-catalysts by an exciting mixture of SiO2 and MgO to generate COx-bare hydrogen and nanocarbon simultaneously from methane decomposition reactions. SiO2/MgO mixed oxides with different ratios (0.5, 1, and 2) were ready via a facile co-precipitation method from magnesium nitrate and sodium metasilicate and used as supports for various nickel contents (30, 40, 50, and 60 wt%) followed by an impregnation technique. Different analytical techniques, such as XRD, BET, SEM, EDS, H2-TPR, and TPO, were used to characterize the catalysts before and after the catalytic runs. The prepared catalysts with various SiO2/MgO molar ratios depicted the BET surface area limiting from 37.9 to 143.4 m2 g−1, indicating remarkable surface improvements. The vast CH4 conversion of 64 % earned on the 50 wt% Ni/SiO2·MgO at 575 °C. Moreover, lower deactivation was detected regarding this catalyst at 600 min on stream.

Thermocatalytic decomposition of methane to low-carbon hydrogen using LaNi1-xCuxO3 perovskite catalysts

The thermocatalytic decomposition (TCD) of methane is an attractive alternative to produce low-carbon hydrogen and solid carbonaceous materials. In this study, substituted LaNi1-xCuxO3 perovskite catalysts prepared via self-combustion method were investigated for methane TCD. The effect of Ni partial substitution with Cu, varying gas hourly space velocity, temperature and stability on methane conversions were evaluated. PXRD, H2-TPR, SEM-EDS, TGA, and XPS were used to characterize the catalysts. An increase in Cu loading to 50%, increase in temperature and decrease in GHSV resulted in an improvement in methane conversions to 92%. At a GHSV of 2400 ml/gcat.h, no significant deactivation was observed as the stability of the LaNi0.5Cu0.5O3 catalyst increased from 6 to 20 hours’ TOS with methane conversions maintained at 92% where carbon nanofibers were observed on the surface of the spent catalysts. The study demonstrates the potential to prepare LaNi1-xCuxO3 catalysts and identify optimal testing conditions for the novel production of low-carbon hydrogen with minimal catalyst deactivation.

Toward Rational Design of Nickel Catalysts for Thermocatalytic Decomposition of Methane for Carbon Dioxide‐Free Hydrogen and Value‐Added Carbon Co‐Product: A Review

AbstractThermocatalytic decomposition of methane provides opportunities for hydrogen (H2) production with no emission of carbon dioxide. However, high‐value carbon products need to be produced for economic deployment of thermocatalytic decomposition and to achieve a minimum H2 selling price below the U.S, Department of Energy target of $ 1/kg H2. In this review, we re‐evaluate data on catalyst development reported in the literature and propose correlations between catalyst characteristics, catalytic stability, and properties of carbon co‐products. In the first part of the review, growth mechanisms for carbon nanotubes using state‐of‐the‐art chemical vapor deposition are reviewed to catalog the effects of catalyst characteristics, the influence of carbon sources, interactions between metal particles and supports, and metal particle sizes on carbon growth. In the second part, representative developments in mono‐, bi‐, and tri‐metallic nickel catalysts are highlighted. We present kinetic analysis of reactions catalyzed by mono‐metallic nickel catalysts, which generates a correlation between metal particle size and catalyst stability. Rational design of Ni‐based catalysts for TCD of methane requires attention to the size of the metal particle and effective normalization of the reaction rates. Further attention to the distribution of the metal particle sizes may help identify catalyst properties that contribute longevity and selectivity to processes that use them. While it is tempting to focus on the highest valued carbon products (e. g., CNTs and CFs), analysis of the markets for other carbon products suggests that a more flexible approach may generate comparable returns without the risk associated with specialization.

Obtaining Hydrogen by Thermocatalytic Decomposition of Methane Using a Catalyst ‘Nickel on Kieselgur’

The process of hydrogen production through thermocatalytic decomposition of methane using a “nickel on kieselgur” catalyst on a quartz sand substrate with a thickness of 1 cm in the “sand-catalyst-sand” configuration was investigated in this work. The experimental results revealed a dependence of the percentage yield of hydrogen on temperature within the temperature range of 530°C to 770°C. As a result, a hydrogen content of 68% in the gas mixture was achieved at the reactor outlet under the conditions of 770°C temperature and a methane flow rate of 2 l/h.

Comparative analysis of a batch and continuous fluidized bed reactors for thermocatalytic decomposition of methane: A CFD-DEM-MGM approach

ThermoCatalytic Decomposition of methane (TCD) has shown great potential for synthesis of valuable carbon nanomaterials as well as hydrogen production, however due to the importance of the phenomena operating at different scales, it is a complex process to model and predict. During the TCD process methane is decomposed to hydrogen gas and solid carbon. Carbon is accumulated on the catalyst particle and leads to larger but less active catalyst particles. In this study, a Computational Fluid Dynamics-Discrete Element Method-Multi Grain Model (CFD-DEM-MGM) was employed to investigate two catalytic fluidized bed reactors for TCD with the same dimensions. Case-1 involved a batch of catalyst particles staying in the reactor during the process, while Case-2 featured a continuous reactor with removal of catalyst particles from the bottom and the introduction of fresh particles from the side. Results showed that the continuous reactor had lower catalyst particle growth and reduced deactivation due to limited residence time, yet demonstrated higher carbon production and gas conversion. Case-1, with larger catalyst particles, experienced reduced bubble formation, while in Case-2 the continuous removal/introduction of particles enhanced solids mixing. Internal diffusion limitations affected reactor performance, emphasizing the CFD-DEM-MGM model’s potential for optimizing fluidized bed reactor design and gas-solid contacting in the TCD process.

Scalable Synthesis of Oxygen Vacancy-Rich Unsupported Iron Oxide for Efficient Thermocatalytic Conversion of Methane to Hydrogen and Carbon Nanomaterials.

Thermocatalytic methane decomposition (TCMD) involving metal oxides is a more environmentally friendly and cost-effective strategy for scalable hydrogen fuel production compared to traditional methane steam reforming (MSR), as it requires less energy and produces fewer CO/CO2 emissions. However, the unsupported metal oxide catalysts (such as α-Fe2O3) that would be suited for this purpose exhibit poor performance in TCMD. To overcome this issue, a novel strategy was developed as a part of this work, whereby oxygen vacancies (OVs) were introduced into unsupported α-Fe2O3 nanoparticles (NPs). Systematic characterization of the obtained materials through analytical techniques demonstrated that mesoporous nanostructured unsupported α-Fe2O3 with abundant oxygen vacancies (OV-rich α-Fe2O3 NPs) could be obtained by direct thermal decomposition of ferric nitrate at different calcination temperatures (500, 700, 900, and 1100 °C) under ambient conditions. The thermocatalytic activity of the resulting OV-rich α-Fe2O3 NPs was assessed by evaluating the methane conversion, hydrogen formation rate, and amount of carbon deposited. The TCMD results revealed that 900 °C was the most optimal calcination temperature, as it led to the highest methane conversion (22.5%) and hydrogen formation rate (47.0 × 10-5 mol H2 g-1 min-1) after 480 min. This outstanding thermocatalytic performance of OV-rich α-Fe2O3 NPs is attributed to the presence of abundant OVs on their surfaces, thus providing effective active sites for methane decomposition. Moreover, the proposed strategy can be cost-effectively scaled up for industrial applications, whereby unsupported metal oxide NPs can be employed for energy-efficient thermocatalytic CH4 decomposition into hydrogen fuel and carbon nanomaterials.

Production of Pure Hydrogen through Thermocatalytic Methane Decomposition Using NiO-MgO Catalysts Promoted by Chromium and Copper Prepared via Mechanochemical Method

The burning of fossil fuels enhanced the greenhouse gas emissions in the atmosphere and caused serious environmental problems; so, it is necessary to find a replacement energy source. Hydrogen is considered one of the clean and viable energy carriers. Thermocatalytic methane decomposition (TMD) allows the production of COx-free H2 and solid carbon with excellent attributes and high potential. In this study, 50NiO-MgO (50 wt.% NiO and 50 wt.% MgO) and Cu- and Cr-doped samples were synthesized via the mechanochemical route. Structural characteristics of the fresh and spent catalysts were analyzed by different analysis methods. The results demonstrated that the specific surface area improved by introducing chromium to the catalyst formulation. Between all of the samples, the 50NiO-MgO-15Cr2O3 (50 wt.% NiO, 35 wt.% MgO, and 15 wt.% Cr2O3) showed the higher BET surface area with an amount of 38.3 m2/g. The performance of 50NiO-MgO and Cr- and Cu-doped catalysts was tested in the thermocatalytic methane decomposition. The obtained result showed that the Cr-doped sample possessed higher methane conversion with the amount of 65% at 575°C and much better lifetime due to its positive impact on the reducibility of the catalyst. Also, the influence of GHSV (gas hourly space velocity) was investigated on the catalytic performance of this sample which was chosen as the optimum catalyst.

Thermocatalytic Decomposition of Methane: A Review on Carbon-Based Catalysts.

The global initiatives on sustainable and green energy resources as well as large methane reserves have encouraged more research to convert methane to hydrogen. Catalytic decomposition of methane (CDM) is one optimistic route to generate clean hydrogen and value-added carbon without the emission of harmful greenhouse gases, typically known as blue hydrogen. This Review begins with an attempt to understand fundamentals of a CDM process in terms of thermodynamics and the prerequisite characteristics of the catalyst materials. In-depth understanding of rate-determining steps of the heterogeneous catalytic reaction taking place over the catalyst surfaces is crucial for the development of novel catalysts and process conditions for a successful CDM process. The design of state-of-the-art catalysts through both computational and experimental optimizations is the need of hour, as it largely governs the economy of the process. Recent mono- and bimetallic supported and unsupported materials used in CDM process have been highlighted and classified based on their performances under specific reaction conditions, with an understanding of their advantages and limitations. Metal oxides and zeolites have shown interesting performance as support materials for Fe- and Ni-based catalysts, especially in the presence of promoters, by developing strong metal-support interactions or by enhancing the carbon diffusion rates. Carbonaceous catalysts exhibit lower conversions without metal active species and largely result in the formation of amorphous carbon. However, the stability of carbon catalysts is better than that of metal oxides at higher temperatures, and the overall performance depends on the operating conditions, catalyst properties, and reactor configurations. Although efforts to summarize the state-of-art have been reported in literature, they lack systematic analysis on the development of stable and commercially appealing CDM technology. In this work, carbon catalysts are seen as promising futuristic pathways for sustained H2 production and high yields of value-added carbon nanomaterials. The influence of the carbon source, particle size, surface area, and active sites on the activity of carbon materials as catalysts and support templates has been demonstrated. Additionally, the catalyst deactivation process has been discussed, and different regeneration techniques have been evaluated. Recent studies on theoretical models towards better performance have been summarized, and future prospects for novel CDM catalyst development have been recommended.

Fabrication and evaluation of the Mn-promoted Ni/FeAl2O4 catalysts in the thermocatalytic decomposition of methane: Impact of various promoters

This research is focused on the designing and developing catalytic systems over various metal oxides (CuO, Cr2O3, Co3O4, ZnO, and MnO2) promoted NiO/FeAl2O4 catalysts in the thermocatalytic decomposition of CH4. The catalysts were synthesized based on the wet impregnation method, and the nominal NiO content was fixed at 50 wt% along with each transition metal at 10 wt%. The controlled preparation method caused the sample doped with MnO2 to show the highest specific surface area (46.8 m2/g) and the lowest particle size (10.6 nm) among the promoted samples. The activity test revealed that the MnO2(10)-NiO(50)/FeAl2O4 catalyst was the most active and stable catalyst in the CH4 decomposition reaction. At 700 °C, the CH4 conversion and H2 yield were 62.3 and 66 % over this catalyst. Also, the decline in its initial activity was only 3 % during the 300 min reaction time at 575 °C. Also, the results indicated that the catalytic efficiency and rate of carbon production increased by raising the MnO2 content from 5 to 10 wt%. However, the high amount of the deposited carbon and decline in metal dispersion led to the catalytic activity being reduced when the MnO2 loading was increased from 10 to 15 wt%. The impact of calcination temperature (600, 700, and 800 °C) was also investigated on the characterization features and conversion rate of the selected catalyst, and the results revealed that the catalyst calcined at 600 °C displayed the highest efficiency under studied conditions. Furthermore, the results indicated that the catalytic activity and stability decreased by increasing the GHSV value from 40000 to 60000 ml.h−1.g-1cat and CH4:N2 molar ratio from 10:90 to 30:70. Also, the CH4 conversion decreased from 47 to 28 % when the reduction temperature increased from 700 to 800 °C, respectively.

Promotional role of NiCu alloy in catalytic performance and carbon properties for CO2-free H2 production from thermocatalytic decomposition of methane

The addition of Cu to Ni inhibits catalyst deactivation and changes carbon co-product morphology during the thermocatalytic decomposition of methan.

Influence of various spinel materials supported Ni catalysts on thermocatalytic decomposition of methane for the production of COx-free hydrogen

The thermocatalytic decomposition of methane is a promising method to produce COx-free hydrogen. The spinel powders with the common formula of AB2O4 and unparalleled features were widely used as a support of heterogeneous catalysts for the diverse catalytic process. In this research, the spinel powders containing the oxides of magnesium, calcium, barium, strontium, iron, and zinc were synthesized based on the solid-state mechanochemical preparation method, and the samples were used as catalyst support for the nickel-based catalysts in the thermal decomposition of methane for the production of COx-free hydrogen. XRD, BET, CO2-TPD, H2-TPR, TPO, and FESEM techniques were carried out to identify the physicochemical characteristics of the fresh and spent samples. The results showed that all samples have a nanocrystalline structure with excellent properties. The results demonstrated that the FeAl2O4-supported nickel catalyst presented the highest stability among the studied catalysts. The decline in the initial CH4 conversion was about 21% at 575 °C during the 300 min time on stream. However, other samples were completely deactivated during the stability test, which was related to the deposition and growth of the carbon nanofiber that covers the available catalyst active sites. The effect of the GHSV value (40000–60,000 ml.h−1.g−1cat), CH4:N2 (10:90–30:70), and reduction temperature (600–800 °C) were also investigated on the catalytic performance and rate of the deposited carbon of the 40 wt% NiO/FeAl2O4.

Thermocatalytic Decomposition of Methane Over NiO–MgO Catalysts Synthesized by the Mechanochemical Method

Thermocatalytic Decomposition of Methane Over NiO–MgO Catalysts Synthesized by the Mechanochemical Method

Kinetic study of thermocatalytic decomposition of methane over nickel supported catalyst in a fluidized bed reactor

ThermoCatalytic Decomposition of methane (TCD) offers an interesting route to convert natural gas into hydrogen and functional carbon. In this study the reaction kinetics of TCD is studied for a nickel supported catalyst using a special fluidized bed reactor. The effect of operating conditions such as temperature, concentrations of methane and hydrogen and space velocity (SV) was studied on a commercial nickel catalyst on a silica support. The performance of the catalyst was evaluated in terms of three parameters: maximum reaction rate, lifetime and carbon yield. Values up to and in excess of 70gC/gcat and 12h (at 550 °C and 70vol.% CH4-5vol.% H2) have been achieved for carbon yield and lifetime, respectively. The carbon product has fish bone structure. Our study has revealed that at lower temperatures and in the presence of small amounts of hydrogen (≤10%) a higher carbon yield is obtained. Lower concentration of methane (higher concentration of the inert) lowers the reaction rate, the lifetime and therefore the carbon yield. A dual kinetic approach has been adopted to determine maximum reaction rate and the associated deactivation factor. The kinetic parameters were estimated for the temperature range of 550-600 °C.

Hydrogen production from COx-Free thermocatalytic decomposition of methane over the mesoporous iron aluminate spinel (FeAl2O4) nanopowder supported nickel catalysts

In the present study, the thermocatalytic decomposition of methane (TDM) was performed over the NiO(x)/FeAl2O4 catalysts with various contents of nickel oxide. The FeAl2O4 catalyst support with mesoporous structure and high SBET (80.26 m2 g−1) was synthesized according to the carbonate-based mechanochemical method. The calcined catalysts were characterized by the XRD, BET, H2-TPR, CO2-TPD, TPO, and FESEM analyses. The obtained results demonstrated that the SBET of the synthesized catalysts reduced from 62 to 26 m2 g−1 by increasing the nickel loading from 20 to 60 wt.%, which is ascribed to the blockage of FeAl2O4 support pores. Furthermore, the activity results showed that the catalytic activity improved by increasing the nickel content from 20 to 50 wt.% due to the rise of active site concentration. However, the methane conversion was reached to 40% at 600 °C over the NiO(50)/FeAl2O4 catalyst. The more increment of nickel content decreased the catalytic efficiency due to the decline in active phase dispersion. Moreover, the increment amount of deposited carbon was seen by increasing the weight percentage of NiO. Therefore, the catalyst with 50 wt.% of NiO possessed excellent catalytic potential in the TDM process under the hard operating conditions (GHSV = 50,000 ml.h−1.g−1cat). The influence of GHSV, feed ratio (CH4:N2), calcination temperature, and reduction temperature on the textural properties and catalytic activity of the NiO(50)/FeAl2O4 catalyst were also evaluated in detail.

Low-emission hydrogen production via the thermo-catalytic decomposition of methane for the decarbonisation of iron ore mines in Western Australia

The Pilbara, located in Western Australia is one of the largest iron ore-mining regions in the world and will need to achieve significant emission reductions in the short term to conserve the limited carbon budget and abide by the Paris Agreement targets. Green hydrogen has been communicated as the desired solution, however, the high production cost limits the deployment of these systems. The thermo-catalytic methane decomposition (TCMD) process is an alternative solution, which could be implemented as a bridge technology to produce low-emission hydrogen at a potentially lower cost. This is especially attractive for iron ore mines due to the utilisation of iron ore as a process catalyst, which reduces the catalyst turnover costs and can increase the grade of spent iron ore catalyst. In this study, a preliminary techno-economic assessment was carried out in comparison with green hydrogen to determine the feasibility of the TCMD process for the decarbonisation of iron ore mine sites in the Pilbara. The results show that the TCMD process had a CO2 abatement cost between 25 and 40% less than green hydrogen, however, the magnitude of these costs was lowest for mining operations >60 Mt/yr at approximately $150 and $200 USD/t CO2 respectively. Since green hydrogen is expected to have significant cost reductions in the future, integrating renewables already into the mine could reduce emissions in the short term, which could then be extended for green hydrogen production once it becomes viable. The TCMD process, therefore, only has a narrow window of opportunity, although considering the uncertainty of the process and that green hydrogen is a proven technology with greater emission-reduction potential, green hydrogen may be the most suitable solution despite the model results presented in this work.

Synthesis of non-cytotoxic Co3O4 nanocatalysts for thermocatalytic methane decomposition by resource recovery

Synthesis of non-cytotoxic Co3O4 nanocatalysts for thermocatalytic methane decomposition by resource recovery

Influence of Various Spinel Materials Supported Ni Catalysts on Thermocatalytic Decomposition of Methane for the Production of Cox-Free Hydrogen

Influence of Various Spinel Materials Supported Ni Catalysts on Thermocatalytic Decomposition of Methane for the Production of Cox-Free Hydrogen

Thermo catalytic decomposition of methane over Cu - Al2O3 and 5 - 20wt% Ni - Cu - Al2O3 catalysts to produce hydrogen and carbon nanofibers

Thermo catalytic decomposition of methane over Cu - Al2O3 and 5 - 20wt% Ni - Cu - Al2O3 catalysts to produce hydrogen and carbon nanofibers

Mathematical modelling and simulation of the thermo-catalytic decomposition of methane for economically improved hydrogen production

The demand for low-emission hydrogen is set to grow as the world transitions to a future hydrogen economy. Unlike current methods of hydrogen production, which largely derive from fossil fuels with unabated emissions, the thermo-catalytic methane decomposition (TCMD) process is a promising intermediate solution that generates no direct carbon dioxide emissions and can bridge the transition to green hydrogen whilst utilising existing gas infrastructure. This process is yet to see widespread adoption, however, due to the high catalyst turnover costs resulting from the inevitable deactivation of the catalyst, which plays a decisive role in the feasibility of the process. In this study, a feasible TCMD process was identified and a simplified mathematical model was developed, which provides a dynamic estimation for the hydrogen production rate and catalyst turnover costs over various process conditions. The work consisted of a parametric study as well as an investigation into the different process modes. Based on the numerous simulation results it was possible to find the optimal process parameters that maximise the hydrogen production rate and minimise the catalyst turnover costs, therefore increasing the economic potential of the process and hence its commercial viability.

Thermocatalytic Hydrogen Production Through Decomposition of Methane-A Review.

Consumption of fossil fuels, especially in transport and energy-dependent sectors, has led to large greenhouse gas production. Hydrogen is an exciting energy source that can serve our energy purposes and decrease toxic waste production. Decomposition of methane yields hydrogen devoid of COx components, thereby aiding as an eco-friendly approach towards large-scale hydrogen production. This review article is focused on hydrogen production through thermocatalytic methane decomposition (TMD) for hydrogen production. The thermodynamics of this approach has been highlighted. Various methods of hydrogen production from fossil fuels and renewable resources were discussed. Methods including steam methane reforming, partial oxidation of methane, auto thermal reforming, direct biomass gasification, thermal water splitting, methane pyrolysis, aqueous reforming, and coal gasification have been reported in this article. A detailed overview of the different types of catalysts available, the reasons behind their deactivation, and their possible regeneration methods were discussed. Finally, we presented the challenges and future perspectives for hydrogen production via TMD. This review concluded that among all catalysts, nickel, ruthenium and platinum-based catalysts show the highest activity and catalytic efficiency and gave carbon-free hydrogen products during the TMD process. However, their rapid deactivation at high temperatures still needs the attention of the scientific community.