PERFORMANCE COMPARISON OF SYNGAS METHANATION ON FLUIDIZED AND FIXED BED REACTORS

The performance was compared on Syngas Completely Methanation at atmospheric pressure on fluidized and fixed bed reactors. From space-time yield of CH4, coke content and hot spots of bed temperature, fluidized bed technology was demonstrated to be more applicable to Syngas Completely Methanation. Characterization results showed that different carbon deposition forms were presented on the two operation modes

Template synthesis of novel porous carbons and their applications

Ph.DDOCTOR OF PHILOSOPH

A reinforced study on the synthesis of microporous titanosilicate ETS-10

10.1016/j.micromeso.2004.08.004Microporous and Mesoporous Materials761-3113-122MIMM

Ordered mesostructured carbon templated by SBA-16 silica

A novel synthesis of ordered cubic mesoporous carbon with an Im3m symmetry by using SBA-16 silica as a hard template was performed. SBA-16 was synthesized using pluronic F 127 as the structure-directing agent and tetra- ethylorthosilicate as the silica source. Carbon replication of the surfactant-removed mesoporous silica was performed at 900°C using sucrose as a carbon source in the presence of sulfuric acid. It was found that surfactants removal method plays an important role in the formation of carbon mesostructures

Synthesis of nanostructured porous carbon

In this paper, high-surface-area porous carbons with crumpled nanowalls were synthesized by carbonization of sucrose in the presence of zeolite template. The pore structures of the carbon materials were characterized using physical adsorption of nitrogen. Their surface chemistry was analyzed using X-ray photoelectron spectrometer (XPS). The microscopic structure features of the samples were imaged by field-emission scanning electron microscope (FESEM) and transmission electron microscopy (TEM). The nanostructure of synthesized porous carbon with a combination of micro-, meso- and macropores has been obtained

High-performance nickel manganese ferrite/oxidized graphene composites as flexible and binder-free anodes for Li-ion batteries

This work demonstrates a new method for fabrication of mixed metal oxide/oxidized graphene (OGP) composites as flexible and binder-free anode materials for Li-ion batteries. The composites containing nickel manganese ferrite (Ni0.5Mn0.5Fe2O4 (NMFO)) nanoparticles grown on an OGP network structure are fabricated by a facile solvothermal method. In the synthesis, Ni(CH3COO)(2), Mn(CH3COO)(2), and FeCl3 are used as the metal precursors; CH3COONa, HOCH2CH2OH and distilled water as the mixed solvent. The flexible and binder-free electrodes are prepared by coating OGP and NMFO/OGP on polypropylene microporous film via vacuum filtration. The multilayer and porous structure of the NMFO/OGP film generate good contact between the electrode materials and the current collector (OGP film), which is essential for flexible devices. As anticipated, both the free-standing NMFO/OGP film and NMFO/OGP coated on polypropylene microporous film exhibit super-flexible properties without using any binder. The obtained flexible and binder-free electrodes show good electrochemical performance with high lithium storage capacity and excellent cycling stability. This work opens a new way for fabrication of flexible and binder-free anode materials for Li-ion batteries.</p

Catal. Sci. Technol.

Ni-Mg/Al2O3 catalysts prepared with methods of co-precipitation (CP), homogeneous precipitation (HP) and acid-base pairing (ABP) were tested for syngas methanation at 623-923 K in a stainless steel fixed bed reactor and further characterized to justify their performances. The Ni-Mg/Al2O3 catalysts prepared with CP using NH4OH, NaOH and Na2CO3 as the precipitants followed an activity order of NaOH &gt; NH4OH &gt; Na2CO3. Comparing further with the samples prepared by HP and ABP resulted in an activity order of HP &gt; ABP &gt; CP (NaOH) for syngas methanation under 0.1 MPa. For CO conversion, a transition of reaction control from kinetic dominance to thermodynamic dominance was observed at about 780 K. Performing 20 h continuous tests at 773 K and under 0.1 and 2.5 MPa further verified the stability of the HP, ABP and CP (NaOH) catalysts for syngas methanation. Analyzing the catalysts via H-2-TPR clarified that a lower amount of free NiO and a stronger interaction between the dispersed NiO and Al2O3 or MgO ensured better catalytic performance for methanation. The study also identified two types of carbon deposited on the surface of the spent catalysts.Ni-Mg/Al2O3 catalysts prepared with methods of co-precipitation (CP), homogeneous precipitation (HP) and acid-base pairing (ABP) were tested for syngas methanation at 623-923 K in a stainless steel fixed bed reactor and further characterized to justify their performances. The Ni-Mg/Al2O3 catalysts prepared with CP using NH4OH, NaOH and Na2CO3 as the precipitants followed an activity order of NaOH > NH4OH > Na2CO3. Comparing further with the samples prepared by HP and ABP resulted in an activity order of HP > ABP > CP (NaOH) for syngas methanation under 0.1 MPa. For CO conversion, a transition of reaction control from kinetic dominance to thermodynamic dominance was observed at about 780 K. Performing 20 h continuous tests at 773 K and under 0.1 and 2.5 MPa further verified the stability of the HP, ABP and CP (NaOH) catalysts for syngas methanation. Analyzing the catalysts via H-2-TPR clarified that a lower amount of free NiO and a stronger interaction between the dispersed NiO and Al2O3 or MgO ensured better catalytic performance for methanation. The study also identified two types of carbon deposited on the surface of the spent catalysts

Methane storage in a template-synthesized carbon

Methane adsorption was investigated in a template carbon synthesized with sucrose as carbon precursor and ammonium-form zeolite Y as template. The carbon sample possesses a surface area of ∼1500 m/g and is comprised of both micropores and mesopores. Adsorption experiments show that the carbon presents a methane sorption capacity of 8.0 mmol/g at 300 K and 35 bar. The low bulk density of the as-synthesized carbon powder was improved by the fabrication of carbon pellets on which a volumetric methane storage capacity of 93 (v/v) was achieved

Replicating novel carbon nanostructures with 3D macroporous silica template

Three-dimensional macroporous carbon, carbon capsules with and without opening windows, solid carbon spheres and walnut-like carbon nanostructures were fabricated with macroporous silica as a template. The relationship between the structures and experimental conditions was studied. The carbon materials reported here may find application as photonic crystals, drug delivery systems, catalyst supports, and adsorbents

Defect engineering in self-assembled 3D photonic crystals

This work describes the combination of photolithography and self-assembly methods for fabrication of 3D photonic crystals (PCs) with well-defined micron-scale line defects embedded in the PCs. Line defects with different dimensions, shapes, and compositions have been introduced into the 3D PCs by choosing different photoresists, masks, and template-directed assembly techniques. Infiltration of carbon using high-temperature chemical vapour deposition (CVD) technique showed that the fabrication procedure offers an ideal approach to functional 3D photonic devices from self-assembled photonic crystals