Decomposition of Carbon Tetrachloride by a Packed Bed Plasma Reactor

1997 ◽  
Vol 2 (2) ◽  
Author(s):  
G. Prieto ◽  
O. Prieto ◽  
C. R. Gay ◽  
K. Mizuno ◽  
I. Tamori ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Plasma Reactor ◽  
Packed Bed ◽  
Operating Conditions ◽  
Empirical Modeling ◽  
Atmospheric Pollutants ◽  
Packed Bed Reactor ◽  
Volatile Organic ◽  
Reactor Operating ◽  
Decomposition Efficiency

AbstractIn search of a technology capable of controlling atmospheric pollutants, like volatile organic compounds (VOCs) in low concentrations, this paper is concerned with the empirical modeling of a ferroelectric plasma packed-bed reactor at ambient temperature and pressure. The empirical model gives information about the decomposition efficiency of the process as a function of the reactor operating variables. The volatile organic compound selected is Carbon Tetrachloride balanced with air in the concentration-range of 150 to 600 ppm and flow-range of 175 to 325 ml/min. Regarding the decomposition efficiency as the objective function, this modeling provides valuable information about the optimal operating conditions.

Decomposition of Toluene, o-Xylene, Trichloroethylene, and Their Mixture Using a BaTiO3 Packed-Bed Plasma Reactor

1996 ◽  
Vol 1 (1) ◽  
Author(s):  
Toshiaki Yamamoto ◽  
Jen-Shih Chang ◽  
Alex A Berezin ◽  
Hitoshi Kohno ◽  
Shigeo Honda ◽  
...  
Keyword(s):  
Gas Flow ◽  
Plasma Reactor ◽  
Nonthermal Plasma ◽  
Packed Bed ◽  
Operating Conditions ◽  
Destruction Efficiency ◽  
Volatile Organic ◽  
Reactor Operating ◽  
Reactant Conversion ◽  
Plasma Technologies

AbstractNonthermal plasma technologies offer an innovative approach to the problem of decomposing various volatile organic compounds (VOCs). We focused on an AC-energized ferroelectric packed-bed plasma reactor to study the decomposition/destruction efficiency and byproduct analysis for toluene, o-xylene, trichloroethylene, and their mixture from 50 to 230 ppm in dry air. The effects of gas flow rate, concentration, moisture content, and reactor operating conditions on the decomposition and analysis of reactant conversion for each VOC were investigated for suitable applications of the emerging technology. Laboratory-scale packed-bed plasma technology was successfully demonstrated for the application of VOC control in semiconductor clean room environments.

A New Reactor Concept for Efficient Solar-Thermochemical Fuel Production

2013 ◽  
Vol 135 (3) ◽  
Author(s):  
Ivan Ermanoski ◽  
Nathan P. Siegel ◽  
Ellen B. Stechel
Keyword(s):  
Solar Energy ◽  
High Efficiency ◽  
Packed Bed ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Reactive Material ◽  
Starting Point ◽  
Wide Range ◽  
Solar Thermochemical ◽  
The U.S

We describe and analyze the efficiency of a new solar-thermochemical reactor concept, which employs a moving packed bed of reactive particles produce of H2 or CO from solar energy and H2O or CO2. The packed bed reactor incorporates several features essential to achieving high efficiency: spatial separation of pressures, temperature, and reaction products in the reactor; solid–solid sensible heat recovery between reaction steps; continuous on-sun operation; and direct solar illumination of the working material. Our efficiency analysis includes material thermodynamics and a detailed accounting of energy losses, and demonstrates that vacuum pumping, made possible by the innovative pressure separation approach in our reactor, has a decisive efficiency advantage over inert gas sweeping. We show that in a fully developed system, using CeO2 as a reactive material, the conversion efficiency of solar energy into H2 and CO at the design point can exceed 30%. The reactor operational flexibility makes it suitable for a wide range of operating conditions, allowing for high efficiency on an annual average basis. The mixture of H2 and CO, known as synthesis gas, is not only usable as a fuel but is also a universal starting point for the production of synthetic fuels compatible with the existing energy infrastructure. This would make it possible to replace petroleum derivatives used in transportation in the U.S., by using less than 0.7% of the U.S. land area, a roughly two orders of magnitude improvement over mature biofuel approaches. In addition, the packed bed reactor design is flexible and can be adapted to new, better performing reactive materials.

scholarly journals Modeling and Design of a Multi-Tubular Packed-Bed Reactor for Methanol Steam Reforming over a Cu/ZnO/Al2O3 Catalyst

Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 610 ◽  
Author(s):  
Jimin Zhu ◽  
Samuel Simon Araya ◽  
Xiaoti Cui ◽  
Simon Lennart Sahlin ◽  
Søren Knudsen Kær
Keyword(s):  
Steam Reforming ◽  
Packed Bed ◽  
Methanol Conversion ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Inlet Temperature ◽  
Methanol Steam Reforming ◽  
Shell Side ◽  
Co Concentration ◽  
The Impact

Methanol as a hydrogen carrier can be reformed with steam over Cu/ZnO/Al2O3 catalysts. In this paper a comprehensive pseudo-homogenous model of a multi-tubular packed-bed reformer has been developed to investigate the impact of operating conditions and geometric parameters on its performance. A kinetic Langmuir-Hinshelwood model of the methanol steam reforming process was proposed. In addition to the kinetic model, the pressure drop and the mass and heat transfer phenomena along the reactor were taken into account. This model was verified by a dynamic model in the platform of ASPEN. The diffusion effect inside catalyst particles was also estimated and accounted for by the effectiveness factor. The simulation results showed axial temperature profiles in both tube and shell side with different operating conditions. Moreover, the lower flow rate of liquid fuel and higher inlet temperature of thermal air led to a lower concentration of residual methanol, but also a higher concentration of generated CO from the reformer exit. The choices of operating conditions were limited to ensure a tolerable concentration of methanol and CO in H2-rich gas for feeding into a high temperature polymer electrolyte membrane fuel cell (HT-PEMFC) stack. With fixed catalyst load, the increase of tube number and decrease of tube diameter improved the methanol conversion, but also increased the CO concentration in reformed gas. In addition, increasing the number of baffle plates in the shell side increased the methanol conversion and the CO concentration.

scholarly journals High-Resolution SEM and EDX Characterization of Deposits Formed by CH4+Ar DBD Plasma Processing in a Packed Bed Reactor

Nanomaterials ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 589 ◽  
Author(s):  
Mohammadreza Taheraslani ◽  
Han Gardeniers
Keyword(s):  
High Resolution ◽  
Elemental Analysis ◽  
Morphological Changes ◽  
Plasma Reactor ◽  
Packed Bed ◽  
Amorphous Structure ◽  
Dielectric Surface ◽  
Packed Bed Reactor ◽  
Lower Amount ◽  
Dbd Plasma

The deposits formed during the DBD plasma conversion of CH4 were characterized by high-resolution scanning electron microscopy (HRSEM) and energy dispersive X-ray elemental analysis (EDX) for both cases of a non-packed reactor and a packed reactor. For the non-packed plasma reactor, a layer of deposits was formed on the dielectric surface. HRSEM images in combination with EDX and CHN elemental analysis of this layer revealed that the deposits are made of a polymer-like layer with a high content of hydrogen (60 at%), possessing an amorphous structure. For the packed reactor, γ-alumina, Pd/γ-alumina, BaTiO3, silica-SBA-15, MgO/Al2O3, and α-alumina were used as the packing materials inside the DBD discharges. Carbon-rich agglomerates were formed on the γ-alumina after exposure to plasma. The EDX mapping furthermore indicated the carbon-rich areas in the structure. In contrast, the formation of agglomerates was not observed for Pd-loaded γ-alumina. This was ascribed to the presence of Pd, which enhances the hydrogenation of deposit precursors, and leads to a significantly lower amount of deposits. It was further found that the structure of all other plasma-processed materials, including MgO/Al2O3, silica-SBA-15, BaTiO3, and α-alumina, undergoes morphological changes. These alterations appeared in the forms of the generation of new pores (voids) in the structure, as well as the moderation of the surface roughness towards a smoother surface after the plasma treatment.

scholarly journals Technological, economic and environmental evaluation of rice husk gasification in a biorefinery context to produce indirect energy as jet fuel

2017 ◽  
Vol 8 (2) ◽  
pp. 61-70
Author(s):  
Juan Jacobo Jaramillo Obando ◽  
Angie Vanessa Arias Suns
Keyword(s):  
Production Process ◽  
Rice Husk ◽  
Packed Bed ◽  
Jet Fuel ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Added Value ◽  
Total Production ◽  
Higher Alcohol ◽  
Environmental Evaluation

Higher alcohol 1-octanol was evaluated as jet fuel potential. The synthesis of the 1-octanol was modeled and the technological, economic and environmental evaluation of the global production process of the rice husk gasification was performed. The best operating conditions to 1-octanol synthesis were obtained in packed bed reactor PBR using Matlab software. Mass and energy balances were calculated using Aspen Plus Software. Economic assessment was developed using Aspen Process Economic Analyzer Software. Environmental impact evaluation was carried out using the waste reduction algorithm WAR. Process yield was 0.83 kg of 1-Octanol by kg of rice husk. Total production cost obtained was USD 0.957 per kg of 1-octanol and the total PEI of product leave the system is 0.08142 PEI/kg with a PEI mitigated of 12.97 PEI/kg. Production process of high alcohols from rice husk shows a high potential technological, economical and environmental as a sustainable industry at take advantage of an agroindustrial residue and transformed in products with added value and energy. 1-octanol as jet fuel has a potential but need to be more studied for direct use in jet motors.

Modeling and Simulation of a Packed-bed Reactor for Carrying out the Water-Gas Shift Reaction

2012 ◽  
Vol 10 (1) ◽  
Author(s):  
Yaidelin A. Manrique ◽  
Carlos V. Miguel ◽  
Diogo Mendes ◽  
Adelio Mendes ◽  
Luis M. Madeira
Keyword(s):  
Fixed Bed ◽  
Packed Bed ◽  
Packed Bed Reactor ◽  
Fixed Bed Reactor ◽  
Water Gas Shift ◽  
Small Scale ◽  
Heterogeneous Model ◽  
Co Conversion ◽  
Reactor Operating ◽  
Water Gas

Abstract In this work the water-gas shift (WGS) process was addressed, with particular emphasis in the development of phenomenological models that can reproduce experimental results in a WGS reactor operating at low temperatures. It was simulated the conversion obtained in a fixed-bed reactor (PBR) packed with a Cu-based catalyst making use of a composed kinetic equation in which the Langmuir-Hinshelwood rate model was used for the lowest temperature range (up to 215 ºC), while for temperatures in the range 215 – 300 ºC a redox model was employed. Several packed-bed reactor models were then proposed, all of them without any fitting parameters. After comparing the simulations against experimental CO conversion data for different temperatures and space time values, it was concluded that the heterogeneous model comprising axial dispersion and mass transfer resistances shows the best fitting. This model revealed also good adherence to other experiments employing different feed compositions (CO and H2O contents); it predicts also the overall trend of increasing CO conversion with the total pressure. This modeling work is particularly important for small scale applications related with hydrogen production/purification for fuel cells.

Reaction-driven instabilities in down-flow packed beds

1995 ◽  
Vol 450 (1938) ◽  
pp. 1-21 ◽  
Keyword(s):  
Hot Spots ◽  
Three Dimensional ◽  
Packed Bed ◽  
Operating Conditions ◽  
Packed Bed Reactor ◽  
Three Dimensional Model ◽  
One Dimensional ◽  
Packed Bed Reactors ◽  
First Order ◽  
The One

Flow maldistributions and corresponding hot spots may cause adverse effects in the operation of down-flow packed-bed reactors. To avoid these phenomena it is necessary to know when and how they occur. In this work, a three-dimensional model that considers the effects of fluid flow, mass transfer by diffusion, heat transfer by conduction and reactant consumption by an exothermic irreversible first-order reaction is used to analyse an adiabatic packed-bed reactor with down-flow. It is shown that the one-dimensional uniform down-flow can become unstable to three-dimensional stationary and time-dependent perturbations, giving rise to non-uniform flow fields that lead to fixed as well as moving hot spots. The boundary of the region of the operating conditions at which these instabilities occur is determined as a function of the various physicochemical parameters that characterize the packed-bed reactor.

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