Flow Distribution Characteristics of a Gas-Liquid Monolith Reactor

Flow Distribution Characteristics in a 0.05 M Diameter Monolith Reactor, Operated Co-Current Downward in the Taylor Flow Regime, Was Investigated and Quantified using Gamma Ray Computed Tomography (CT). the Results Indicate that the Flow Distribution is a Strong Function of Liquid Distributor Design, and Gas and Liquid Superficial Velocities. Additionally, within the Range of Gas and Liquid Superficial Velocities Investigated, a Window of Operating Condition (Gas and Liquid Velocities) Was Identified Which Resulted in a Close to Uniform Phase Distribution. © 2005 Elsevier B.V. All Rights Reserved

Liquid Saturation and Gas-Liquid Distribution in Multiphase Monolithic Reactors

The Monolith Bed is One of the Promising Catalytic Reactors for a Number of Chemical Gas-Liquid-Solid Processes. in the Present Work, Liquid Saturations for Five Different Monoliths Have Been Investigated Experimentally in a Cold-Flow Unit with a Reactor Diameter of 5.0 Cm. the Influences of Gas and Liquid Flow Rates and of the Direction of Two-Phase Flow on Liquid Saturation Were Examined. the Results Indicate that the Direction of Flow Has No Significant Influence on Liquid Saturation for Proper Gas-Liquid Distribution. the Experimental Results Are in Good Agreement with Predictions of the Drift Flux Model using the Distribution Parameter Proposed by Ishii (ANL Report ANL-77-47, 1977) Along with the Assumption of Zero Drift Velocity. in Preliminary Experiments, Gamma-Ray Computed Tomography (CT) Has Been Successfully Applied to Measure Time-Averaged Liquid Distribution over the Monolith Cross-Section in a Selected Condition. the Employment of a Nozzle-Type Distributor Provides an Almost Uniform Liquid Distribution over the Monolith Substrate. It is Demonstrated that CT is a Viable Technique for Studying Two-Phase Flow in Laboratory-Scale Monolith Reactors. © 2005 Elsevier Ltd. All Rights Reserved

Integration of Phase Distribution from Gamma-Ray Tomography Technique with Monolith Reactor Scale Modeling

In this work, a monolith reactor model was developed to study the effect of phase distribution on the performance of the monolith reactors by integrating phase distribution data from the experiments. To obtain the phase distribution at the reactions conditions, gamma ray computed tomography (CT) was used. Effect of gas density, surface tension of liquid and operating conditions on the phase distribution were studied using gamma-ray computed tomography. Experiments were conducted in Taylor flow regime. With the increase in gas density, uniformity increases. Surface tension has little effect on the distribution in the investigated conditions. Liquid with lower surface tension and gas with lower density has higher cross-sectional liquid saturation. Further, the monolith reactor model with uniform phase distribution and actual distribution were compared. It was found that at higher velocities both gives the same reactor performance irrespective of the maldistribution, however at low velocities, they differ significantly due to the maldistribution. If the maldistribution is present at both low and high velocities, catalyst utilization plays a major role, thus it is recommended to operate at higher velocities where catalyst utilization is high due to high mass transfer

Effect of Phase Maldistribution on Performance of Two-Phase Catalytic Monolith Reactor and its Comparison with Trickle Bed Reactor

Monolith reactors are widely considered as an alternative to the conventional trickle bed reactor. For the commercial deployment of monolith reactors, comparative performance studies are required. Reliable comparative and performance studies require a detailed understanding of the effect of phase distribution/maldistribution on the performance studies. In this work, performance and comparative studies were carried out in a relatively large column that was 4.8 cm in diameter. Experiments were performed in the same conditions that were used in studies for which phase distribution data were available. Since the properties of the catalyst used were different in both the reactors, the apparent kinetics were studied to facilitate the comparison. The hydrogenation of alpha-methyl styrene (AMS) was used as a test reaction. From the performance studies, it was found that the effect of maldistribution on the performance was stronger than the catalyst availability. From the comparative studies, it was found that the monolith reactor with maldistributed flow conditions provides higher productivity than the trickle bed reactor

Countercurrent Flow Distribution in Structured Packing Via Computed Tomography

A Newly Developed Γ-Ray Computed Tomography Scanner Was Implemented to Study Liquid Flow Distribution in a 30.48-Cm-Diameter Column Packed with Corrugated Structure using Countercurrent Air-Water Flow. Validation Experiments Confirm that Spatial Resolution of ∼2.5 Mm Can Be Achieved by the New CT Unit. within the Gas (0-10 Cm/s Superficial Velocity) and Liquid (0.6-2.5 Cm/s Superficial Velocity) Flow Ranges Investigated, a Good Liquid Distribution Was Observed at All Conditions, as Manifested by Uniformity Factor in Excess of 70%. the Liquid Saturation Increases with Increasing Superficial Liquid Velocity as Well as Down the Column Height. within the Conditions Studied, the Effect of Gas Velocity Was, in General, Found to Be Minimal. © 2004 Elsevier B.V. All Rights Reserved