Cobalt Catalyst Characterization for Methane Decomposition and Carbon Nanotube Growth

Oliveira, Hugo A.; Franceschini, D. F.; Passos, Fábio B.

doi:10.5935/0103-5053.20140243

Cited by 7 publications

(6 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…5%); thus, signal-to-noise ratios for observed peaks in the XRD spectra were anticipated to be low. However, in studies by Oliveira et al [22] and Abad-Elwahad et al [23], XRD peaks for cobalt species were detected in materials with as low as 3% Co, which is comparable to the loading in our samples.…”

Section: Xrd Results: As-prepared and Heated Aerogels And Xerogelssupporting

confidence: 84%

Cobalt-alumina sol gels: Effects of heat treatment on structure and catalytic ability

Bouck

Anderson

Prasad

et al. 2016

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

Cobalt-alumina (Co-Al) aerogel catalysts show potential as less expensive, sustainable alternatives to the platinum-group-metal catalysts used in three-way catalytic converters. Effects of heat treatment on the structure of Co-Al xerogels and aerogels and catalytic performance of Co-Al aerogels were investigated. Alumina gels were prepared by epoxide-assisted sol-gel synthesis, impregnated with ~3% cobalt, and either processed via rapid supercritical extraction to yield aerogels, or dried under ambient conditions to form xerogels. These materials were calcined at temperatures ranging from 400°C to 1100°C and characterized using scanning electron microscopy, energy dispersive x-ray spectroscopy, powder xray diffraction, thermogravimetric analysis and Brunauer-Emmett-Teller gas adsorption. When the aerogels and xerogels were heated to ~500˚C, crystalline portions of the alumina support underwent the expected phase transformation from boehmite to γ-alumina. Aerogels resisted further changes in samples heated to 1100˚C, whereas γ-alumina in the xerogels converted to α-alumina by 1100˚C. Heat-treated aerogels had high thermal stability, evidenced by their maintaining a surface area of 400 (± 30) m 2 /g after significant heating and resisting catalytically inhibiting θ/α-alumina phase changes. Color changes observed following heating are consistent with changes in cobalt-containing species within the materials.Preliminary catalytic tests showed that pre-heating Co-Al aerogels to 750˚C improves catalytic performance.

show abstract

Section: Xrd Results: As-prepared and Heated Aerogels And Xerogelssupporting

confidence: 84%

Cobalt-alumina sol gels: Effects of heat treatment on structure and catalytic ability

Bouck

Anderson

Prasad

et al. 2016

Journal of Non-Crystalline Solids

View full text Add to dashboard Cite

show abstract

“…This reaction temperature has been reportedly used in experimental study of dry reforming of CH 4 for syngas (H 2 and CO) production over different supported metal catalysts [38,37]. Previous literature reports have shown that temperatures > 800°C often led to catalyst deactivation via carbon deposition; hence a decrease in the subsequent conversion of CO 2 and CH 4 , as well as the yield of the syngas [18,39,40]. The ratio of H 2 to CO produced is unity which makes the syngas a suitable feedstock for Fischer-Trospsc synthesis (FTS) [41].…”

Section: Process Simulationmentioning

confidence: 96%

“…Using feed ratio > 1 will make CH 4 to be in excess, hence, the formation of carbon during its decomposition might not get sufficient free O2 to be removed. This often results to deposition of the carbon on the surface of the catalyst, thereby resulting to deactivation [18]. The reaction temperature for the dry reforming reaction is set at 800°C.…”

Section: Process Simulationmentioning

confidence: 99%

“…However, due to endothermic nature of the dry reforming reaction, high temperature greater than 750°C is usually required to start the reaction [14,15]. Several studies have shown that high temperature required for dry reforming reaction often leads to catalysts deactivation through carbon deposition and sintering [16,17,18]. Furthermore, syngas production can be enhanced through combination of dry reforming with partial oxidation reforming process.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Process Modelling, Thermodynamic Analysis and Optimization of Dry Reforming, Partial Oxidation and Auto-Thermal Methane Reforming for Hydrogen and Syngas production

Ayodele

Cheng

2015

Chemical Product and Process Modeling

View full text Add to dashboard Cite

In this work, process modelling, thermodynamic analysis and optimization of stand-alone dry and partial oxidation reforming of methane as well as, the auto-thermal reforming processes were investigated. Firstly, flowsheet models were developed for both the stand-alone systems and auto-thermal reforming process using ASPEN HYSYS ® . Furthermore, thermodynamic studies were conducted for the stand-alone and auto-thermal reforming processes for temperatures range of 200-1000°C and pressure range of 1-3 bar using Gibbs free energy minimization methods which was also performed using ASPEN HYSYS ® . The simulation of the auto-thermal reforming process was also performed at 20 bar to mimic industrial process. Process parameters were optimized in the combined reforming process for hydrogen production using desirability function. The simulation results show that 84.60 kg/h, 62.08 kg/h and 154.7 kg/h of syngas were produced from 144 kg/h, 113 kg/h and 211 kg/h of the gas fed into the Gibbs reactor at CH 4 /CO 2 /O 2 ratio 1:1:1 for the stand-alone dry reforming, partial oxidation reforming and auto-thermal processes respectively. Equilibrium conversion of CH 4 , CO 2 , O 2 were thermodynamically favoured between 400 and 800°C with highest conversions of 100%, 95.9% and 86.7% for O 2 , CO 2 and CH 4 respectively. Highest yield of 99% for H 2 and 40% for CO at 800°C was obtained. The optimum conditions for hydrogen production were obtained at CH 4 /CO 2 , CH 4 /O 2 ratios of 0.634, 0.454 and temperature of 800°C respectively. The results obtained in this study corroborate experimental studies conducted on auto-thermal reforming of methane for hydrogen and syngas production.

show abstract

“…Nevertheless, the usage of Ni-based catalysts in dry reforming of methane has been constraint by their susceptibility to catalyst deactivation via sintering and carbon depositions [27]. Supported Co-catalyst which is less expensive compared to noble-metal catalysts has been reported as a good alternative to Ni-based catalysts in terms of stability [28].…”

Section: Introductionmentioning

confidence: 99%

Synthesis, Characterization and Catalytic Performance of Ceria-Supported Cobalt Catalyst for Methane Dry Reforming to Syngas

2017

MJAS

View full text Add to dashboard Cite

In this study the synthesis, characterization and catalytic performance of CeO 2 (Ceria) supported Co catalyst was investigated. First, the ceria was synthesized by direct thermal decomposition of Ce(NO 3 ) 3 .6H 2 O and subsequently impregnated with 20 wt.% Co using aqueous solution of Co(NO 3 ) 2 .6H 2 O as a precursor. The synthesized catalyst was characterized using TGA, N 2 -adsorption-desorption, X-ray Diffractometry (XRD), Field Emission Scanning Electron Microscope (FESEM-EDX), and Fourier Transformation Infrared (FTIR). The catalytic property of the ceria-supported cobalt catalyst was tested in methane dry reforming using a stainless steel fixed bed reactor. The dry reforming reaction was performed at the temperature range of 923-1023 K under a controlled atmospheric pressure and constant gas hourly space velocity (GHSV) of 30000 h -1 . The effects of reactant (CH 4 and CO 2 ) feed ratio was investigated on reactants conversion, product yields, and selectivity. The ceria-supported cobalt catalyst recorded highest catalytic activity at a CH 4 : CO 2 ratio of 0.9 and temperature of 1023 K. The highest values of 79.5% and 87.6% were recorded for the CH 4 and CO 2 conversions respectively. Furthermore, highest yields of 41.98% and 39.76%, as well as selectivity of 19.56% and 20.72%, were obtained for H 2 and CO respectively. Syngas ratio of 0.90 was obtained from the dry reforming of methane, making it suitable as feedstock for Fischer-Tropsch synthesis (FTS). Keywords: ceria, cobalt, Fischer-Trosch synthesis, methane dry reforming, syngas AbstrakDalam kajian ini, sintesis, pencirian berserta prestasi tindakbalas pemangkin Co/CeO 2 telah dijalankan. Terdahulu, ceria disintesis daripada penguraian terma secara langsung ke atas Ce(NO 3 ) 3 .6H 2 O, diikuti oleh formulasi dengan 20% logam Co menggunakan larutan akueus Co(NO 3 ) 2 .6H 2 O sebagai pelopor. Mangkin yang diperolehi dicirikan dengan menggunakan kaedah TGA, N 2 -penjerapan penyaherapan, pembelauan sinar X (XRD), Mikroskop Pengimbas Elektron Pancaran Medan -Sinar-X Serakan Tenagan (FESEM-EDX) dan Inframerah Tranformasi Fourier (FTIR). Prestasi pemangkin Co/CeO 2 telah diuji untuk tindakbalas penghasilan metana kontang di dalam reaktor keluli tahan karat. Tindakbalas kimia tersebut telah dijalankan pada suhu berjulat daripada 923-1023 K, tekanan 1 atm serta GHSV bersamaan 30000 h -1 . Kesan nisbah reaktan (CH 4 and CO 2 ) terhadap penukaran reaktan serta hasil dan pemilihan produk telah disiasat. Mangkin Co/CeO 2 mencatatkan aktiviti pemangkin paling tinggi pada nisbah CH 4 /CO 2 bersamaan 0.9 dan suhu 1023 K. Penukaran CH 4 and CO 2 mencatatkan nilai tertinggi bersamaan 79.5% dan 87.6%. Tambahan pula, hasil tertinggi bersamaan 37.6% dan 40% berserta sifat pemilihan bersamaan 19.56% dan 20.72% untuk H 2 dan CO telah direkodkan. Nisbah gas sintesis bersamaan 0.9 telah diperolehi daripada penghasilan semula metana kontang bersesuaian untuk tindakbalas sintesis Fischer-Trosch.

show abstract

Cobalt Catalyst Characterization for Methane Decomposition and Carbon Nanotube Growth

Cited by 7 publications

References 0 publications

Cobalt-alumina sol gels: Effects of heat treatment on structure and catalytic ability

Cobalt-alumina sol gels: Effects of heat treatment on structure and catalytic ability

Process Modelling, Thermodynamic Analysis and Optimization of Dry Reforming, Partial Oxidation and Auto-Thermal Methane Reforming for Hydrogen and Syngas production

Synthesis, Characterization and Catalytic Performance of Ceria-Supported Cobalt Catalyst for Methane Dry Reforming to Syngas

Contact Info

Product

Resources

About