Hydrogen Production by Carbon-Catalyzed Methane Decomposition Via Thermogravimetry

2016 ◽  
Vol 139 (1) ◽  
Author(s):  
Vidyasagar Shilapuram ◽  
Nesrin Ozalp
Keyword(s):  
Weight Gain ◽  
Hydrogen Production ◽  
Reaction Temperature ◽  
Reaction Rate ◽  
Carbon Deposition ◽  
Activated Carbons ◽  
Catalyst Activity ◽  
High Energy ◽  
Methane Decomposition ◽  
Carbon Formation

Hydrogen is a high energy content fuel and methane is currently the most preferred feedstock for hydrogen production. Direct thermal splitting of methane offers the cleanest technique to produce hydrogen and carbon as coproduct fuel. Carbonaceous catalysts have significant impact on methane to hydrogen conversion. This study presents thermogravimetric experiment results of carbon-catalyzed methane decomposition using commercial catalyst. Results are presented in terms of carbon formation rate, amount of carbon deposition on the catalyst, sustainability factor, catalyst activity, and kinetics of the reaction. The results show that weight gain because of carbon formation depends on reaction temperature, methane volume percent in the feed gas, and nature of the carbonaceous catalyst. It was observed that the reaction rate was dominant at the beginning, and deactivation rate was dominant toward the end of reaction. X-ray diffraction (XRD) and scanning electron microscopic (SEM) analysis of deactivated catalytic samples show decreasing disorder with increasing reaction temperature. Finally, performance comparison of activated carbons (ACs) studied in literature shows that activated carbon sample chosen in this study outperforms in terms of carbon deposition, reaction rate, carbon weight gain, and sustainability factor.

Effects of Reaction Temperature on CO2 Reforming of CH4 over Multi-Walled Carbon Nanotubes Catalyst with Co-Mo-MgO Nanoparticles

2013 ◽  
Vol 756 ◽  
pp. 182-189 ◽  
Author(s):  
Mehrnoush Khavarian ◽  
Abdul Rahman Mohamed
Keyword(s):  
Carbon Nanotubes ◽  
Reaction Temperature ◽  
Reaction Rate ◽  
Carbon Deposition ◽  
Research Field ◽  
Energy Research ◽  
Mgo Nanoparticles ◽  
Multi Walled Carbon Nanotubes ◽  
Activity Behavior ◽  
Walled Carbon Nanotubes

The utilization of greenhousegases, such as carbon dioxide (CO2) and methane (CH4), is among the most important challenges in the energy research field. The catalytic activity behavior of CO2 reforming of CH4 (CRM) over synthesized multi-walled carbon nanotubes (MWCNTs) with Co-Mo and MgO nanoparticles was investigated. Based on conversion of reactants and production of syngas, the synthesized Co-Mo-MgO/MWCNTs were found to be a suitable catalyst for the CRM reaction. The CH4 and CO2 conversions were greatly influenced by the reaction temperature in the range of 750-1000 °C. The catalyst exhibited high activity and stability during 10 h reaction time with 82.68% conversion of CH4 at 950 °C respectively,without significant deactivation. The reaction rate of CH4 and CO2 over carbon nanotubes was affected significantly by the reaction temperature.The syngas ratio was close to unity and no carbon deposition over the catalyst was observed after the termination of the reaction.

scholarly journals Low Temperature Activation of Carbon Dioxide by Ammonia in Methane Dry Reforming—A Thermodynamic Study

Catalysts ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 481 ◽  
Author(s):  
Anand Kumar
Keyword(s):  
Carbon Dioxide ◽  
Low Temperature ◽  
Hydrogen Production ◽  
Catalyst Activity ◽  
Dry Reforming ◽  
Equilibrium Analysis ◽  
Attractive Alternative ◽  
Carbon Formation ◽  
Methane Dry Reforming ◽  
Ammonia Addition

Methane dry reforming (MDR) is an attractive alternative to methane steam reforming for hydrogen production with low harmful environmental emissions on account of utilizing carbon dioxide in the feed. However, carbon formation in the product stream has been the most challenging aspect of MDR, as it leads to catalyst deactivation by coking, prevalent in hydrocarbon reforming reactions. Common strategies to limit coking have mainly targeted catalyst modifications, such as by doping with rare earth metals, supporting on refractory oxides, adding oxygen/steam in the feed, or operating at reaction conditions (e.g., higher temperature), where carbon formation is thermodynamically restrained. These methods do help in suppressing carbon formation; nonetheless, to a large extent, catalyst activity and product selectivity are also adversely affected. In this study, the effect of ammonia addition in MDR feed on carbon suppression is presented. Based on a thermodynamic equilibrium analysis, the most significant observation of ammonia addition is towards low temperature carbon dioxide activation to methane, along with carbon removal. Results indicate that ammonia not only helps in removing carbon formation, but also greatly enriches hydrogen production.

scholarly journals Effect of nanostructured supports on catalytic methane decomposition

2000 ◽  
Vol 72 (1-2) ◽  
pp. 327-331 ◽  
Author(s):  
L. Ji ◽  
S. Tang ◽  
P. Chen ◽  
H. C. Zeng ◽  
J. Lin ◽  
...  
Keyword(s):  
Carbon Deposition ◽  
Sol Gel ◽  
Methane Decomposition ◽  
Molar Ratio ◽  
Carbon Formation ◽  
Commercial Catalyst ◽  
Support Particle ◽  
Different Types ◽  
Support Size ◽  
Effect Of Support

Carbon deposition from catalytic methane decomposition has drawn increasing interest recently. Previously, we have found the carbon formation depends on the crystalline structure of the support, following the trend of Ni/CeO2 > Ni/CaO > Ni/MgO, because Ni supported on MgO is uniformly dispersed and can stabilize high-x CH x intermediates. We have also found that the addition of Pt can inhibit the carbon deposition on Co/Al2O3 because the alloying between Pt and Co results in the better dispersion of Co on the support. Furthermore, it was revealed that by judging the Ni/Mg molar ratio from 1 to 0.25 we could reduce the diameter of deposited carbon nanotubes from 20 to 12 nm, with substantially smaller production rate. All of these previous studies indicated that better dispersion of the supported metal would benefit the decreasing of carbon deposition. Here we present our recent investigation of the effect of support particle size on the carbon deposition. Three different types of 10 wt% Co/Al2O3 catalysts were prepared: Co on commercial Al2O3 (Cat 1), Co on sol-gel-processed Al2O3 (Cat 2), and sol-gel-made homogeneous Co-in-Al2O3 (Cat 3). TEM showed that the diameter of the Co3O4 particles in sol-gel Al2O3 is only around 6 nm, while it is 20-40 nm in the commercial catalyst. By using XRD and FTIR, Co was identified as crystalline Co3O4 in the as-prepared Cat 1 sample, CoAl2O4 in Cat 2, and amorphous Al2O3 in Cat 3, indicating the best dispersion in Cat 3. Methane CO2 reforming was studied on the three catalysts. Longer lifetime was measured for Cat 3 as compared to those on Cat 1 and Cat 2 (>20 h vs. 1 h). The support size effect is discussed.

Modeling of dry reforming of methane for hydrogen production at low temperatures using membrane reactor

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Cheng-Yang Lu ◽  
Rei-Yu Chein
Keyword(s):  
Reaction Temperature ◽  
Membrane Reactor ◽  
Catalyst Activity ◽  
Dry Reforming ◽  
Operating Conditions ◽  
Dry Reforming Of Methane ◽  
Membrane Thickness ◽  
Hydrogen Yield ◽  
Carbon Formation ◽  
Reactor Operation

Abstract The hydrogen removal and carbon formation effects in dense palladium (Pd)-based membrane reactors for dry reforming of methane (DRM) performance is numerically analyzed in this study. The steady-state membrane reactor operation is described using a three-dimensional, heterogeneous, non-isothermal mathematical model. Based on the numerical simulation results for reaction temperature and pressure varied in the 400–600 °C and 1–30 atm ranges, methane conversion and hydrogen yield were found enhanced using the membrane reactor. However, carbon formation, which affects catalyst activity and limits the benefits of using a membrane reactor is also enhanced. A parametric study using reaction pressure as the primary parameter for the membrane reactor operation found that the CH4 conversion, hydrogen yield, H2 recovery, and carbon formation can be enhanced by increasing the reaction temperature, inlet CO2/CH4 ratio, and sweep gas flow rate. With the enhanced H2 removal, carbon formation is also enhanced. Because membrane permeance is inversely proportional to the membrane thickness, membrane thickness can be used as a parameter to control the carbon formation under given operating conditions.

scholarly journals Direct Amide Synthesis over Composite Magnetic Catalysts in a Continuous Flow Reactor

Catalysts ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 146
Author(s):  
Yawen Liu ◽  
Evgeny V. Rebrov
Keyword(s):  
Reaction Rate ◽  
Flow Reactor ◽  
Catalyst Activity ◽  
High Energy ◽  
Conventional Heating ◽  
Catalyst Loading ◽  
Initial Reaction ◽  
Inductive Heating ◽  
Sulfated Titania ◽  
Temperature Programmed Oxidation

Composite magnetic catalysts containing different amounts of sulfated titania (33–50 wt %) have been prepared by means of high energy ball-milling between TiO2 and NiFe2O4. The catalysts have been characterized with N2 adsorption/desorption isotherms, XRD, temperature programmed oxidation (TPO) and vibrating sample magnetometer (VSM). The catalytic activity was measured in the reaction of aniline and 4-phenylbutyric acid in the continuous mode under conventional and inductive heating. The effect of catalyst loading in the reactor on reaction and deactivation has been studied, indicating the catalyst containing 50 wt % titania gave the highest reaction rate and least deactivation. The operation in a flow reactor under inductive heating increased the amide yield by 25% as compared to conventional heating. The initial reaction rate decreased by 30% after a period of 15 h on stream. The catalyst activity was fully restored after a treatment with an air flow at 400 °C.

Statistical Modeling of Hydrogen Production Via Carbonaceous Catalytic Methane Decomposition

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Vidyasagar Shilapuram ◽  
Bishwadeep Bagchi ◽  
Nesrin Ozalp ◽  
Richard Davis
Keyword(s):  
Hydrogen Production ◽  
Statistical Modeling ◽  
Catalyst Deactivation ◽  
Catalyst Activity ◽  
Decomposition Reaction ◽  
Initial Reaction Rate ◽  
Methane Decomposition ◽  
Quadratic Model ◽  
Initial Reaction ◽  
Statistical Regression

Hydrogen production via carbonaceous catalytic methane decomposition is a complex process with simultaneous reaction, catalyst deactivation, and carbon agglomeration. Conventional reaction and deactivation models do not predict the progress of reaction accurately. Thus, statistical modeling using the method of design of experiments (DoEs) was used to design, model, and analyze experiments of methane decomposition to determine the important factors that affect the rates of reaction and deactivation. A variety of statistical models were tested in order to identify the best one agreeing with the experimental data by analysis of variance (ANOVA). Statistical regression models for initial reaction rate, catalyst activity, deactivation rate, and carbon weight gain were developed. The results showed that a quadratic model predicted the experimental findings. The main factors affecting the dynamics of the methane decomposition reaction and the catalyst deactivation rates for this process are partial pressure of methane, reaction temperature, catalytic activity, and residence time.

Kinetics of carbon monoxide methanation on a Ni/SiO2 catalyst

1990 ◽  
Vol 55 (7) ◽  
pp. 1678-1685
Author(s):  
Vladimír Stuchlý ◽  
Karel Klusáček
Keyword(s):  
Carbon Monoxide ◽  
Reaction Rate ◽  
Catalyst Activity ◽  
Adsorbed Hydrogen ◽  
Reaction Products ◽  
Co Methanation ◽  
Molar Ratios ◽  
Rate Determining Step ◽  
Higher Temperature ◽  
Kinetics Of

Kinetics of CO methanation on a commercial Ni/SiO2 catalyst was evaluated at atmospheric pressure, between 528 and 550 K and for hydrogen to carbon monoxide molar ratios ranging from 3 : 1 to 200 : 1. The effect of reaction products on the reaction rate was also examined. Below 550 K, only methane was selectively formed. Above this temperature, the formation of carbon dioxide was also observed. The experimental data could be described by two modified Langmuir-Hinshelwood kinetic models, based on hydrogenation of surface CO by molecularly or by dissociatively adsorbed hydrogen in the rate-determining step. Water reversibly lowered catalyst activity and its effect was more pronounced at higher temperature.

Mechanisms of methane decomposition and carbon species oxidation on the Pr0.42Sr0.6Co0.2Fe0.7Nb0.1O3−σ electrode with high catalytic activity

2015 ◽  
Vol 3 (45) ◽  
pp. 22816-22823 ◽  
Author(s):  
Peng Zhang ◽  
Guoqing Guan ◽  
Deni S. Khaerudini ◽  
Xiaogang Hao ◽  
Chunfeng Xue ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Carbon Deposition ◽  
Methane Decomposition ◽  
High Catalytic Activity ◽  
Carbon Species

Carbon deposition characteristics on PSCFN and Ni–YSZ due to thermal CH4 decomposition are investigated by using TPR technique.

scholarly journals 1.8 V Aqueous Symmetric Carbon-Based Supercapacitors with Agarose-Bound Activated Carbons in an Acidic Electrolyte

Nanomaterials ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1731
Author(s):  
Chih-Chung Lai ◽  
Feng-Hao Hsu ◽  
Su-Yang Hsu ◽  
Ming-Jay Deng ◽  
Kueih-Tzu Lu ◽  
...  
Keyword(s):  
Activated Carbon ◽  
Sulfuric Acid ◽  
Energy Density ◽  
Activated Carbons ◽  
High Energy ◽  
Aqueous Electrolytes ◽  
Alternative Material ◽  
Aqueous Cells ◽  
Acidic Electrolyte ◽  
Cycling Behavior

The specific energy of an aqueous carbon supercapacitor is generally small, resulting mainly from a narrow potential window of aqueous electrolytes. Here, we introduced agarose, an ecologically compatible polymer, as a novel binder to fabricate an activated carbon supercapacitor, enabling a wider potential window attributed to a high overpotential of the hydrogen-evolution reaction (HER) of agarose-bound activated carbons in sulfuric acid. Assembled symmetric aqueous cells can be galvanostatically cycled up to 1.8 V, attaining an enhanced energy density of 13.5 W h/kg (9.5 µW h/cm2) at 450 W/kg (315 µW/cm2). Furthermore, a great cycling behavior was obtained, with a 94.2% retention of capacitance after 10,000 cycles at 2 A/g. This work might guide the design of an alternative material for high-energy aqueous supercapacitors.

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