We report a computational fluid dynamics-discrete element method (CFD-DEM) simulation study on the interplay between mass transfer and a heterogeneous catalyzed chemical reaction in cocurrent gas-particle flows as encountered in risers. Slip velocity, axial gas dispersion, gas bypassing, and particle mixing phenomena have been evaluated under riser flow conditions to study the complex system be...

The critical mass flow rate is the maximum that can pass through a constrained geometry such as nozzle. For liquid CO2, it has been shown homogeneous relaxation models systematically underpredict rate. In this work, we demonstrate delay of phase transition necessary to reproduce experiments. To analyze in further detail, two methodologies are presented: (1) delayed model (Delayed HRM), and (2) ...

In this study the catalytic dehydrogenation of ethylbenzene to styrene was investigated in a simulated tubular sodalite membrane reactor. The high quality microporous sodalite membrane was synthesized by direct hydrothermal method and characterized by single gas permeation measurements. The performance of the prepared membrane showed high potential for application in a dehydrogenation membrane ...

The early history of a carbon particle is studied as it is suddenly injected into a hot oxidizing atmosphere. In this early phase, a high Reynolds number approach is appropriate. Five stages characterize the processes: (I) inert stage, (2) transition stage (ignition of the heterogeneous reaction), (3) heterogeneous diffusion controlled stage, (4) homogeneous ignition, and (5) overall diffusion-...

We have previously described the use of bronchoscopic lung volume reduction (BLVR), a novel, tissue engineering-based, minimally invasive technique, in experimental homogeneous pulmonary emphysema in sheep. In this report, we describe the use of CTguided, site-directed BLVR in the treatment of experimental heterogeneous emphysema. Nine sheep were treated with localized papain instillations and ...

This paper presents Density Functional Theory and Non-Equilibrium Green’s Function based First Principles calculations to explore the sensing property of Adenine and Thymine based hetero-junction chins for Ammonia and Phosphine gas molecules. This modeling and simulation technique plays an important and crucial role in the fast growing semiconductor based nanotechnology field. The hetero-juncti...

Abstract Dispersivity is a measurable parameter in soil porous media that used for studying the transport of contaminants to groundwater. The value this depends on various factors, including kind (homogeneous or heterogeneous), flow velocity, initial contaminant concentration, travel distance, and sampling method. A physical model with dimensions 0.10 m width, 0.80 height, 1.10 length was const...

The kinetics of nucleation of one-component gas hydrates in aqueous solutions are analyzed. The size of the hydrate nucleus and the work for nucleus formation are determined as functions of the supersaturation Dm: Expressions for the stationary rate J of hydrate nucleation are derived. These expressions describe the JðDmÞ dependence for homogeneous nucleation and for heterogeneous nucleation at...