Publications related to Packed bed

Chat with Graph Search

Ask any question about EPFL courses, lectures, exercises, research, news, etc. or try the example questions below.

DISCLAIMER: The Graph Chatbot is not programmed to provide explicit or categorical answers to your questions. Rather, it transforms your questions into API requests that are distributed across the various IT services officially administered by EPFL. Its purpose is solely to collect and recommend relevant references to content that you can explore to help you answer your questions.

A proof-of-concept prototype of a medium-scale heterogeneous catalytic reactor for continuous production of hydrogen through formic acid (FA) dehydrogenation has been developed. A commercial proton exchange membrane (PEM) fuel cell (FC) fed with the result ...

In the framework of the EU-project SOLZINC, a 300-kW solar chemical pilot plant for the production of zinc by carbothermic reduction of ZnO was experimentally demonstrated in a beam-down solar tower concentrating facility of Cassegrain optical configuratio ...

The overall topic of the investigation was the sepn. of basic proteins by cation exchange displacement chromatog. For this purpose two principal column morphologies were compared for the sepn. of RNase A and a-chymotrypsinogen, two proteins found in the bovine pancreas. These were a column packed with porous particles (Macro-Prep S, 10 mm, 1000 .ANG.) and a monolithic column (UNOTM S1). Both columns are strong cation exchangers, carrying -SO3--groups linked to a hydrophilic polymer support. Poly(diallyl-dim

The use of filamentous catalysts for innovative design of chemical reactors with structured catalytic beds is discussed in detail. The fluid dynamics attained in such reactors avoid transport limitations (mixing or heat- and mass-transfer) and increase reactor performance/safety.

The hydroxylation of benzene was carried out over a structured catalytic bed of ZSM-5-coated stainless steel grids. The catalysts demonstrated a 97% selectivity to PhOH at benzene conversion 11%. In addn. to achieving the same reactivity as traditional zeolitic fixed beds, the grid catalyst has several advantages gained by special arrangement of the catalytic bed, including: low pressure drop, improved heat and mass transfer and controlled hydrodynamics. [on SciFinder (R)]

Industry requires continuously new chemical processes to convert raw materials to valuable products limiting the formation of by-products. Since a few years, an increasing interest has been given to the intensification of chemical processes. This represents a new approach in chemical reaction engineering and calls for a new type of chemical reactors: the microstructured reactors. They are characterized by miniature structures whose components have a sub-millimeter size. The flow channels, for example, have

Woven fibrous materials are proposed as structured catalysts for three-phase catalytic reactors. The design of a catalytic bed arranged as a plate bubble column is discussed. The hydrodynamic parameters, like pressure drop and liq. hold-up were found to depend on the woven structure of the fibrous layers and are shown to be a function of the distance between the threads in the fibers.

A kinetic model for solid-state polycondensation of nylon-6 was developed by extrapolation of the melt chemistry to the amorphous phase of the solid polymer. In this way, a phenomenological description of the process was obtained that required examining al1 possible influences of the semicrystalline structure on the kinetics, equilibrium, and transport phenomena in the polymer granules. Particularly, dramatic apparent kinetics and equilibria changes were postulated due to the confinement of reactive species

The influence of inert particles on liq./solid mass transfer is studied in fluidized beds by using a binary-mixt. of solids of differing size and d. The addn. of inert particles of higher d. and smaller diam., e.g. glass beads, exerts remarkable effects on mass transfer coeffs. in comparison to that of mono-component active particles at the same liq. velocity. The extent of the effect on liq.-solid mass transfer coeffs. increases with an increasing fraction of the small inert particles in the mixt. The liq.

Liq. film mass transfer coeffs. in packed beds and strings of spheres were calcd. theor. using a penetration model for the mass transfer combined with the hydrodynamics of a laminar spherical falling film. The predictions were tested with packed beds varying in packing size from 0.006-0.058 m, bed height from 0.35-1.20 m, column diam. from 0.08-0.50 m; d. of liq. from 996-1152 kg m-3 and viscosity from 2.88-34.66 kgm-1h-1. Strings of spheres tested varied in diam. from 0.0189-0.0381 m, no. of strings from 1

The effective area for mass transfer of the Sulzer structured packing Mellapak 125.Y, 250.Y, and 500.Y was measured under industrial-scale operating conditions, with a broad range of gas and liq. flows, in a pilot plant with a column having an internal diam. of 295 mm and a packing height of 420 mm. The exptl. procedures and app. employed in this work were checked by making addnl. measurements of the effective area for 25-mm ceramic ring packing; these values were compared with literature data. This contrib

Data for the volumetric mass transfer coefficient, kLa, and the effective area, of structured packings have rarely been reported in the literature. This is despite the ever-increasing importance of structured packings in industrial separation columns for absorption and distillation processes. This work verified that the CO2-NaOH reaction is suitable for the determination of effective mass transfer area. The kinetic parameter of this reaction which governs the absorption flux, was evaluated with a wetted wal

The correlations available in the literature cannot be used to est. the liq.-phase mass-transfer coeff. (kL) for viscous solns. Even correlations that agree for water-like viscosities diverge by an order of magnitude for viscosities of only 10 mPa-s. Here, kL (kLa) measurements are given that are performed by stripping O from aq. solns. in a column of 0.3-m diam. filled with 0.025-m glass Raschig rings. The viscosity is varied by varying the amt. of Na alginate, glycerol, or polyethylene glycol in the water

The detn. of glycerol in aq. allergenic products is accomplished by gas chromatog. using a column packed with Chromosorb 101 and FID. Quantitation is performed using the internal std. technique. The method is accurate to within 1% and has proved to be superior to the gas chromatog. method currently recommended in terms of efficiency, selectivity, and reliability. [on SciFinder (R)]

The usefulness of 6-nitro BIPS as a photochromic tracer in org. liqs. was investigated. The photochromic effect of this dye permits the soln. to be decolored conveniently after each tracer expt. so that the same liq. may be used in a closed loop for a large no. of runs, which is essential for large-scale expts. The photochromic behavior of the dye and the stability of its colorless form was studied in a range of solvents. Of all liqs. tested, a no. of alcs. including MeOH, EtOH, and their mixts., with glyce

The effects of the viscosity and surface tension on the axial dispersion and liq. holdup was investigated in a 0.3-m-diam. packed column with countercurrent gas-liq. flow. The axial dispersion appeared to be independent of the viscosity and surface tension. The traditional complex form of correlating Peclet nos. as a function of the interstitial Reynolds and Galileo nos. may be replaced by a much simpler form contg. only the Froude no. as a correlating variable for the liq. phase. The axial dispersion depen

A review is given of gas absorption which is generally used for the gas with the liq. Gas solubilities and mass transfer concepts used in the design of absorption columns (e.g. Kremser-Brown method), film factor concept, penetration theory, and Chilton-Colburn analogy, etc. are discussed. Design procedure (McCabe-Thiele diagram) is described for the bubble tray absorption columns (Murphree liq. plate efficiency). 66 Refs. [on SciFinder (R)]

Gas absorption in packed columns was modelled, taking into account all heat effects for phys. gas absorption. Multicomponent diffusion effects were incorporated in terms of the film-factor concept. An algorithm of very stable convergence behavior was obtained by simulating the start-up procedure of the column dynamically in order to evaluate the steady-state operation. The importance of rigorous design calcns. was assessed by comparing the rigorous soln. with simplified hand calcns. for a large no. of cases

Packed bed

Chat with Graph Search

Heterogeneous Catalytic Reactor for Hydrogen Production from Formic Acid and Its Use in Polymer Electrolyte Fuel Cells

A 300 W solar chemical pilot plant for the carbothermic production of zinc

Investigation of particle-based and monolithic columns for cation exchange protein displacement chromatography using poly(diallyl-dimethylammonium chloride) as displacer

Novel structured materials for structured catalytic reactors

Synthesis of ZSM-5 coatings on stainless steel grids and their catalytic performance for partial oxidation of benzene by N2O

Développement de réacteurs microstructurés pour la conversion du propane en produits valorisés

Fibrous structured catalytic beds for three-phase reaction engineering Hydrodynamics study in staged bubble columns

Kinetic studies and modeling of nylon-6 solid-state polycondensation

Intensification of mass transfer in liquid fluidized beds with inert particles

A simplified penetration model for mass transfer in packed beds and strings of spheres

Effective Mass-Transfer Area in a Pilot Plant Column Equipped with Structured Packings and with Ceramic Rings

Gas absorption experiments in a pilot plant column with the sulzer structured packing mellapack

The influence of viscosity on the liquid-phase mass transfer resistance in packed columns

Improved GC method for determination of glycerol in allergenic products

A tracer system based on a photochromic dye and on fiber optics for measuring axial dispersion of organic liquids in pilot-scale packed columns

Influence of the physical properties of the liquid on axial dispersion in packed columns

Absorption

Rigorous and short-cut design calculations for gas absorption involving large heat effects. 1. A new computational method for packed gas absorbers