Dynamic modelling of a stopped flow fixed bed reactor for gas phase olefin polymerisation

2012 ◽  
Vol 207-208 ◽  
pp. 635-644 ◽  
Author(s):  
B. Browning ◽  
I. Pitault ◽  
N. Sheibat-Othman ◽  
E. Tioni ◽  
V. Monteil ◽  
...  
Keyword(s):  
Gas Phase ◽  
Fixed Bed ◽  
Dynamic Modelling ◽  
Fixed Bed Reactor ◽  
Stopped Flow

Dynamic modelling of a gas phase catalytic fixed bed reactor—III

1976 ◽  
Vol 31 (6) ◽  
pp. 473-479 ◽  
Author(s):  
Sten Bay Jørgensen ◽  
Knud Waede Hansen
Keyword(s):  
Gas Phase ◽  
Fixed Bed ◽  
Dynamic Modelling ◽  
Fixed Bed Reactor

A 2-D observer to estimate the reaction rate in a stopped flow fixed bed reactor for gas phase olefin polymerization

AIChE Journal ◽  
2014 ◽  
Vol 60 (10) ◽  
pp. 3511-3523 ◽  
Author(s):  
Barbara Browning ◽  
Nida Sheibat-Othman ◽  
Isabelle Pitault ◽  
Timothy F. L. McKenna
Keyword(s):  
Gas Phase ◽  
Reaction Rate ◽  
Olefin Polymerization ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Stopped Flow

Dynamic modelling of a gas phase catalytic fixed-bed reactor—II

1976 ◽  
Vol 31 (7) ◽  
pp. 587-598 ◽  
Author(s):  
Knud Waede Hansen ◽  
Sten Bay Jørgensen
Keyword(s):  
Gas Phase ◽  
Fixed Bed ◽  
Dynamic Modelling ◽  
Fixed Bed Reactor

Dynamic modelling of a gas phase catalytic fixed-bed reactor—I

1976 ◽  
Vol 31 (7) ◽  
pp. 579-586 ◽  
Author(s):  
Knud Waede Hansen ◽  
Sten Bay Jørgensen
Keyword(s):  
Gas Phase ◽  
Fixed Bed ◽  
Dynamic Modelling ◽  
Fixed Bed Reactor

Modeling of aerated upflow fixed bed reactors for nitrification

1999 ◽  
Vol 39 (4) ◽  
pp. 85-92 ◽  
Author(s):  
J. Behrendt
Keyword(s):  
Mathematical Model ◽  
Mass Transfer ◽  
Liquid Phase ◽  
Gas Phase ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Bulk Liquid ◽  
Initial Value ◽  
Fixed Bed Reactors ◽  
Number Of Cells

A mathematical model for nitrification in an aerated fixed bed reactor has been developed. This model is based on material balances in the bulk liquid, gas phase and in the biofilm area. The fixed bed is divided into a number of cells according to the reduced remixing behaviour. A fixed bed cell consists of 4 compartments: the support, the gas phase, the bulk liquid phase and the stagnant volume containing the biofilm. In the stagnant volume the biological transmutation of the ammonia is located. The transport phenomena are modelled with mass transfer formulations so that the balances could be formulated as an initial value problem. The results of the simulation and experiments are compared.

Effects of Air Flowrate on the Combustion and Emissions of Blended Corn Straw and Pinewood Wastes

2018 ◽  
Vol 141 (4) ◽  
Author(s):  
Xiaoxiao Meng ◽  
Wei Zhou ◽  
Emad Rokni ◽  
Honghua Zhao ◽  
Rui Sun ◽  
...  
Keyword(s):  
Gas Phase ◽  
Ignition Delay Time ◽  
Fixed Bed ◽  
Combustion Efficiency ◽  
Fixed Bed Reactor ◽  
Corn Straw ◽  
Excess Air ◽  
Burning Rates ◽  
Excess Air Coefficient ◽  
Hazardous Pollutants

This research investigated the effects of the specific primary (under-fire) air flowrate (m˙air) on the combustion behavior of a 50–50 wt % blend of raw corn straw (CS) and raw pinewood wastes in a fixed-bed reactor. This parameter was varied in the range of 0.079–0.226 kg m−2 s−1, which changed the overall combustion stoichiometry from air-lean (excess air coefficient λ = 0.73) to air-rich (excess air coefficient λ = 1.25) and affected the combustion efficiency and stability as well as the emissions of hazardous pollutants. It was observed that by increasing m˙air, the ignition delay time first increased and then decreased, the average bed temperatures increased, both the average flame propagation rates and the fuel burning rates increased, and the combustion efficiencies also increased. The emissions of CO as well as those of cumulative gas phase nitrogen compounds increased, the latter mostly because of increasing HCN, while those of NO were rather constant. The emissions of HCl decreased but those of other chlorine-containing species increased. The effect of m˙air on the conversion of sulfur to SO2 was minor. By considering all of the aforesaid factors, a mildly overall air-rich (fuel-lean) (λ = 1.04) operating condition can be suggested for corn-straw/pinewood burning fixed-bed grate-fired reactors.

scholarly journals Gas-phase elemental mercury removal by nano-ceramic material

2020 ◽  
Vol 10 ◽  
pp. 184798041989975
Author(s):  
Tao Zhu ◽  
Weidong Jing ◽  
Xing Zhang ◽  
Wenjing Bian ◽  
Yiwei Han ◽  
...  
Keyword(s):  
Gas Phase ◽  
Gas Flow ◽  
Removal Rate ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Mercury Removal ◽  
Bet Surface Area ◽  
Mercury Adsorption ◽  
Experimental Conditions ◽  
Physical And Chemical

The nano-ceramic which is mesoporous silica material was applied to test the removal efficiency of gas-phase Hg0 using a fixed-bed reactor. The physical and chemical properties of nano-ceramic were investigated by various techniques such as BET surface area (BET), X-ray diffraction, fourier transform infrared spectrometer (FTIR), and scanning electron microscope (SEM); then, the sample was tested for mercury adsorption under different conditions. The mercury adsorption tests shown that different Hg0 concentration, adsorption temperature, gas flow rate, and different gas components have significant effects on the mercury removal performance of nano-ceramic, and the adsorption removal rate of nano-ceramic can be 75.58% under the optimal experimental conditions. After fitting the experimental data to the adsorption model, it was found that the theoretical maximum mercury adsorption amount q max of nano-ceramic is 1.61 mg g−1 and there were physical and chemical adsorption at the same time. The adsorption kinetics fitting results shown that the adsorption process of nano-ceramic exhibits multi-segment characteristics of “transmembrane–diffusion–adsorption.”

scholarly journals Synthesis of carbon nanotube using ferrocene as carbon source and catalyst in a vertical structured catalyst reactor

2018 ◽  
Vol 67 ◽  
pp. 03038 ◽  
Author(s):  
Praswasti PDK Wulan ◽  
Ghassan Tsabit Rivai
Keyword(s):  
Carbon Nanotube ◽  
Carbon Source ◽  
Gas Phase ◽  
Carbon Deposition ◽  
Fixed Bed ◽  
Catalyst Particle ◽  
Fixed Bed Reactor ◽  
Structured Catalyst ◽  
Catalyst Particle Size

Development of nano-carbon technology in the world has recently occurred due to its excellent electric, thermal, and mechanical properties and it diverse of applications such as electronics, biology, and material. Fixed bed reactor run into blocked due to carbon deposition on the catalyst that cause pressure drop enhancement. Whereas, application of fluidized bed reactor as an alternative of prior reactor have some trouble for complicated of feed flow control that can cause change of catalyst particle size during reaction since agglomeration and adhesion of nanoparticles transpire. Synthesis of carbon nanotube material used a vertical structured catalyst gauze reactor with double furnace system to maintain the catalyst and carbon source in the form of gas phase. This will lead growth of CNT on the surface of the substrate proved by SEM and XRD characterization. Furnace 1 used to ferrocene vaporizer at 400°C and furnace 2 provide substrate placement for CNT growth at 850°C. CNTs characterization confirmed yield and CNT diameter 29.33% and 11.38 nm respectively. Characterization of SEM show that CNT grows on stainless steel type 316 substrate preferable with oxidative heat treatment. Nevertheless, CNTs product still contain many of impurities such as Fe3O4, Fe2O3, Fe3C, hexagonal graphite, and amorphous carbon.

scholarly journals Turnover Rate of Metal-Catalyzed Hydroconversion of 2,5-Dimethylfuran: Gas-Phase Versus Liquid-Phase

Catalysts ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1171
Author(s):  
Hanan Althikrallah ◽  
Casper Kunstmann-Olsen ◽  
Elena F. Kozhevnikova ◽  
Ivan V. Kozhevnikov
Keyword(s):  
Liquid Phase ◽  
Gas Phase ◽  
Furan Ring ◽  
Ambient Pressure ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Ring Cleavage ◽  
Phase Reaction ◽  
Liquid Phase Reaction ◽  
Phase Process

Hydroconversion (hydrogenation and hydrogenolysis) of biomass-derived furanic compounds giving furan ring-hydrogenation and ring-cleavage products attracts interest for sustainable production of chemicals and fuels. Here, the hydroconversion of 2,5-dimethylfuran (DMF), chosen as a model furanic compound, was investigated at a gas-solid interface over carbon-supported Pt, Pd, Rh and Ru metal catalysts in a fixed-bed reactor at 70–90 °C and ambient pressure. Pt/C was mainly active in ring cleavage of DMF to produce 2-hexanone as the primary product, followed by its hydrogenation to 2-hexanol and hexane. In contrast, Pd/C, Rh/C and Ru/C selectively hydrogenated the furan ring to 2,5-dimethyltetrahydrofuran (DMTHF). The turnover frequency (TOF) of metal sites in the gas-phase DMF hydroconversion was determined from zero-order kinetics in the absence of diffusion limitations. The TOF values decreased in the sequence Pt > Rh > Pd >> Ru, similar to the liquid-phase reaction. The TOF values for the gas-phase reaction were found to be one order of magnitude greater than those for the liquid-phase reaction. This indicates that the gas-phase process is potentially more efficient than the liquid-phase process. TOF values for hydroconversion of ring-saturated furan derivatives, tetrahydrofuran and DMTHF, on Pt/C, were much lower than those for DMF.

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