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Catalysts for Syngas Production

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Nguyễn Gia Hào

Academic year: 2023

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Javier Ere ˜na Loizaga Department of Chemical Engineering, University of the Basque Country—UPV/EHU Spain. Since 2000, his research work has mainly focused on the study of the following lines of research (key to the industrial development of the concept of bio-refinery):. This Special Issue on "Catalysts for Syngas Production" shows new research on the development of catalysts and catalytic routes for syngas production, and the optimization of the reaction conditions for the process.

Catalytic Performance and Characterization of Ni-Co Bi-Metallic Catalysts in n-Decane Steam Reforming

Effects of Co Addition

  • Introduction
  • Results and Discussion 1. Catalytic Performance
  • Experimental Section 1. Catalysts Preparation
  • Conclusions

Hydrogen production for fuel cells from steam reforming of ethanol over supported noble metal catalysts.Appl. Hydrogen production for MC fuel cell from steam reforming of ethanol over MgO-supported Ni and Co catalysts. Yttria-stabilized zirconia (YSZ) supports Ni-Co alloys (SOFC anode precursors) as catalysts for ethanol steam reforming.

Figure 1. n-decane conversions and H 2 selectivity over the series catalysts at 650 ◦ C (a), 700 ◦ C (b), 750 ◦ C (c), and 800 ◦ C (d).
Figure 1. n-decane conversions and H 2 selectivity over the series catalysts at 650 ◦ C (a), 700 ◦ C (b), 750 ◦ C (c), and 800 ◦ C (d).

In Situ Regeneration of Alumina-Supported

Cobalt–Iron Catalysts for Hydrogen Production by Catalytic Methane Decomposition

Results and Discussion

In the SP-360 min and SP-720 min samples, the intensity of the carbon lines increased with the time of CMD reaction due to an additional deposition of carbon in well-structured forms that are difficult to eliminate during the regeneration process. In the case of the SP-720 min, the crystallite sizes (XRD or TEM) were the smallest compared to those of other catalysts due to the removal of amorphous carbon species from the MWCNT surface (loss of carbon C→CO2) [46]. BET surface areas of spent and spent/regenerated samples were relatively small compared to that of the fresh sample.

Figure 1. X-ray diffraction (XRD) patterns of fresh, spent, and spent/regenerated catalysts.
Figure 1. X-ray diffraction (XRD) patterns of fresh, spent, and spent/regenerated catalysts.

Experimental Section 1. Preparation of Fresh Catalyst

The effect of Pr addition on the properties of Ni/Al2O3 catalysts with application in autothermal reforming of methane. Int. COx-free hydrogen production from thermal decomposition of methane on activated carbon: Catalyst deactivation. Influence of La on the reduction behavior and surface area of ​​Ni metal of Ni-Al2O3 catalysts for COxfree H2 from the catalytic decomposition of methane. Int.

Hydrogen production by methane decomposition over activated carbon as catalysts: a full factorial design.Int. Ni- and Fe-based catalysts for the production of hydrogen and carbon nanofilaments by the catalytic decomposition of methane in a rotating bed reactor. Ni-Co-Mg-Al catalysts for the production of hydrogen and carbon nanomaterials by CCVD of methane.Catal.

Catalytic thermal decomposition of methane on hydrogen-free and COx-free carbon nanotubes over MgO-supported Group VIII bimetallic catalysts. Thermocatalytic decomposition of methane for hydrogen production using activated carbon catalyst: Regeneration and characterization studies.Int. Fossil hydrogen with reduced CO2 emissions: Modeling the thermocatalytic decomposition of methane in a fluidized bed of carbon particles.

Thermocatalytic decomposition of methane over activated carbon: influence of textural properties and surface chemistry.Int.

A Facile Fabrication of Supported Ni/SiO 2 Catalysts for Dry Reforming of Methane with Remarkably

Materials and Methods 1. Catalyst Preparation

The dry reforming of CH4 with CO2 was carried out at atmospheric pressure in a continuous flow fixed bed quartz tube reactor with an inner diameter of 9 mm. Efficient utilization of greenhouse gas in a gas-to-liquid process combined with carbon dioxide reforming of methane. Environment. Coke Formation over a Nickel Catalyst under Methane Dry Reforming Conditions: Thermodynamic and Kinetic Models.Ind.

Study of short-term catalyst deactivation due to carbon deposition during dry biogas reforming on a supported Ni catalyst. Energy fuels. Elucidation of greater coking resistance of small compared to large nickel nanoparticles in dry methane reforming by computational modeling.Catal. Modification of nickel metallic particle size by H2/CO treatment in Ni/ZrO2Methane catalysts for dry reforming.ACS Catal.

Particle size effect in the low-temperature reformation of methane by carbon dioxide on silica-supported Ni nanoparticles.J. Molecularly tailored nickel precursor and support yield a stable methane-dry reforming catalyst with superior metal utilization.J. In Situ XAS Study of an Improved Natural Phosphate Catalyst for Hydrogen Production by Reforming Methane.Appl.

Synthesis of highly active and stable Ni@Al2O3-embedded catalyst for dry methane reforming: on the confinement effects of Al2O3 shells for Ni nanoparticles.ChemCatChem.

Combined Magnesia, Ceria and Nickel catalyst supported over γ-Alumina Doped with Titania for

Results and Discussion 1. X-ray Powder Diffraction (XRD)

  • H 2 -TPR

An elbow peak was observed for all the samples, except for Ti-CAT-V and Ti-CAT-VI, at a temperature centered around 500◦C. Only two reduction peaks are observed for Ti-CAT-VI at temperature ranges centered at 260 and 325◦C. Ti-CAT-II had the highest CH4 conversion at the start of the reaction (~55%) and maintained stability of about 52%.

The high average pore diameter and pore volume of Ti-CAT-II is a likely factor in the best-in-class performance. The same trend was observed for CO2 conversion, with the Ti-Cat-V catalyst showing the lowest conversion. The Ti-CAT-II catalyst resulted in a H2/CO mol ratio value closer to 1, compared to the tested catalysts.

The TPO profiles of the spent Ti-CAT-I and Ti-CAT-II catalysts are shown in Figure 5. Figure 6 shows SEM micrographs for the best two catalysts: Ti-CAT-I and Ti-CAT-II. The effect of gas hourly space velocity (GHSV) was studied on the catalyst that showed the best results in the previous section (i.e. Ti-CAT-II catalyst).

Quantitative analysis of carbon deposition was performed on the Ti-CAT-II catalyst used in methane-dry reforming at 3 different space velocities and 78,000 ml g−1h−1.

Table 1 summarizes the results of ICP analysis of the metallic components in the prepared catalysts and compares it with the theoretical values
Table 1 summarizes the results of ICP analysis of the metallic components in the prepared catalysts and compares it with the theoretical values

Experimental Section 1. Materials

The reducibility of fresh catalysts was determined by Micromeritics AutoChem II (Micromeritics Instrument Corporation, Norcross, GA, USA). This paper investigated the dry reforming of methane, CH4, over Ti-CAT-V catalyst and the effects of promoters such as CeO2 and MgO, on the catalytic activity and stability of the catalyst. Production of hydrogen and syngas from dry reforming of methane on SBA-15 supported nickel catalysts: On the promotion effect by mixed oxide Ce0.75Zr0.25O2.

Highly active and stable Ni-based bimodal pore catalysts for methane dry reforming. Appl. Study of the dry reforming of methane and ethanol using Rh catalysts on doped alumina. Promotional effect of Ru on the activity and stability of Co/SBA-15 catalysts in methane dry reforming.Int.

Effect of Cu-Mo activities on NiCuMo/Al2O3 catalyst for CO2 reforming of methane.Catal. Preparation and characterization of ultrasonically co-precipitated La-, Ce-, Zr-promoted Ni-Al2O3 catalysts for dry reforming reaction.J. Syngas production over highly active and stable nanostructured NiMgOAl2O3 catalysts in dry methane reforming: Effects of Ni content.

Synthesis, characterization and application of ruthenium-doped SrTiO3 perovskite catalysts for microwave-assisted dry reforming of methane.Chem.

Table 4. Prepared catalyst samples and the wt. % of their composition.
Table 4. Prepared catalyst samples and the wt. % of their composition.

Ni-Mo Sulfide Semiconductor Catalyst with High Catalytic Activity for One-Step Conversion of CO 2

Results and Discussion 1. XRD Analysis

Figure 1a shows the XRD patterns of Ni-Mo sulfide/Al2O3 catalysts with different Ni/Mo molar ratios. Based on the Scherrer equation, the average particle sizes of the Ni-Mo sulfide/Al2O3 catalysts were calculated. In addition, the surface areas of the various Ni-Mo sulphide/Al2O3 catalysts are compared in Table 1.

It seems that the Ni/Mo molar ratio did not significantly affect the surface areas. Figure 2a shows the UV-visible spectra of the Ni-Mo sulfide/Al2O3 catalysts with different Ni/Mo molar ratios, compared to NiS2 and MoS2. This indicates that changing the Ni/Mo molar ratio can significantly adjust the band gaps of the Ni-Mo sulfide/Al2O3 catalysts.

The morphologies and microstructures of the Ni-Mo sulfide/Al2O3 catalyst with Ni/Mo of 5/3 are presented in Figure 3. In addition, all the Ni-Mo sulfide/Al2O3 catalysts showed relatively high BET surface areas (shown in Table 1). Therefore, the reduction in the particle size of the Ni-Mo sulphide/Al2O3 catalyst also contributes to the improvement of the catalytic activity.

The catalysts were designated as xNi(8−x)Mo/Al2O3, where x/(8−x) was the Ni/Mo molar ratio.

Figure 1. The XRD patterns of the Ni-Mo sulfide/Al 2 O 3 catalysts with different Ni/Mo molar ratios (a) scanning angle of 10–90 ◦ ; (b) scanning angle of 30–32.8 ◦ .
Figure 1. The XRD patterns of the Ni-Mo sulfide/Al 2 O 3 catalysts with different Ni/Mo molar ratios (a) scanning angle of 10–90 ◦ ; (b) scanning angle of 30–32.8 ◦ .

Bench-Scale Steam Reforming of Methane for Hydrogen Production

Materials and Methods 1. Catalyst Characterization

The pore size distributions of the samples were calculated using the Barrett-Joyner-Halenda (BJH) model. The catalytic activity of the powdered catalyst for the methane steam reforming reaction was tested in a fixed-bed Inconel tubular reactor (ID=10 mm). A TC was placed in the center of the catalyst bed to monitor the reaction temperature, and the feed flow was controlled using a mass flow controller (Brooks, 5850E, Hatfield, PA, USA).

Nitrogen was used as an internal standard gas to verify the composition of the analytical gas (methane) as volume or half volume. The experiment was carried out under the conditions mentioned above and the method of analysis was the same as that of the laboratory-scale reaction. Under these conditions, the temperature of the heater positioned at the bottom of the reactor (outlet side) mainly governed the methane conversion.

Under abnormal reactor temperature conditions, where the catalyst bed was not sufficiently heated (<650◦C), the reaction was not equilibrated simply by maintaining the bottom heater temperature at 800◦C. A numerical study of the effectiveness factors of nickel catalyst pellets used in steam methane reforming for residential fuel cell applications.Int. Modeling and optimization of methane mixed reforming: maximizing CO2 utilization for non-equilibrated reaction.

This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/).

Table 4. Textural properties of the catalyst used herein.
Table 4. Textural properties of the catalyst used herein.

Recent Advances in Industrial Sulfur Tolerant Water Gas Shift Catalysts for Syngas Hydrogen Enrichment

Application of Lean (Low) Steam/Gas Ratio

  • Lean Steam/gas (Ratio) Sulfur Tolerant Water Gas Shift
  • Catalysts Used for Lean Steam/Gas (Ratio) Sulfur Tolerant Water Gas Shift
  • Catalyst Performances and Characterizations
  • Experimental
  • Summary
  • Expanded Discussion

One useful method is to overfeed the content of water (steam) in the reactant stream which helps to selectively promote the WGS main reaction while effectively suppressing methanation with the reaction equilibrium; therefore a high steam/gas (dry syngas without water) ratio must be applied. When applied in the SWGS process (Figure 1), high steam/gas ratio technology (HSGRT) does not require water complementation before a 2nd WGS reactor (R3); however, medium pressure steam used for a reaction will be added to the pre WGS reactor (R1) and 1st WGS reactor (R2) respectively. CaO was introduced in the preparation of CAT as a common method to improve the catalyst's mechanical strength.

For the D/G ratio, the standard deviation of the measured value is set as unit in the last decimal place. As CAT service years increased (Figure 11b–e), the bands at 1450 and 1100 cm-1 gradually weakened, with the catalytic ability of the WGS decreasing accordingly; the 1450 cm−1 band disappeared completely in the spectra of 4-year-served CAT, which was the most heavily served CAT. The spectra of accidentally deactivated CATs still lacked bands of 1450 and 890 cm−1 (there was a shift to 840 cm−1 in the spectra of sintered CATs); however, the band at 1100 cm-1 was clearly shown despite the signals being much weaker for the ash-poisoned CAT (Figure 12f).

Notably, this new finding was not reported in previous studies of sulfur-tolerant high vapor/gas ratio WGS. Above, the experimental sets used for the laboratory sulfur resistant WGS reaction in selected CATs were discussed. People (F. Wei) from the General Research Institute for Nonferrous Metals (Beijing, China) helped with SEM.

The state of (K)(Ni)Mo/γ-Al2O3 catalysts after water-gas shift reaction in the presence of sulfur in the feed: XPS and EPR study.Appl.

Figure 1. High (1.6 or higher) steam/gas ratio WGS (top) vs. Low steam/gas ratio WGS (bottom).
Figure 1. High (1.6 or higher) steam/gas ratio WGS (top) vs. Low steam/gas ratio WGS (bottom).

Hình ảnh

Figure 1. n-decane conversions and H 2 selectivity over the series catalysts at 650 ◦ C (a), 700 ◦ C (b), 750 ◦ C (c), and 800 ◦ C (d).
Table 1. The textural properties of the fresh and used catalysts.
Table 1 shows the results of N 2 adsorption-desorption results of the fresh and used catalysts.
Figure 4. H 2 -temperature-programmed reduction (H 2 -TPR) results of the series catalysts.
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