Armfield Engineering Education

BASIC PROCESS PRINCIPLES

CEU Catalytic Reactors - Issue 2

CEU utilises the sugar inversion reaction (Sucrose -> Glucose + Fructose) to study the performance of packed bed chemical and biological catalytic reactors. A colorimetric assay is used to determine the degree of conversion using an optical sensor. Assays may be automated using optional flow injection analysis.

Order Specification |
Capabilities |
Description

Optional Accessories |
Requirements |
Shipping Specification and Dimensions

ORDERING SPECIFICATION

A bench top unit comprising a vacuum formed ABS plastic plinth with integral electrical console on to which is mounted the packed bed reactor columns, feed pump, optical sensor and optional Flow Injection Analysis (FIA) system.

The unit is supplied as standard with two reactor columns for chemical catalysis.

A third column can be optionally added to the system for biological (enzymic) catalysis.

A heated water supply to the column jackets allows automatic control of reaction temperature to a set point value.

Feed flow rate can be varied between 0 and 15 ml/min. The FIA pump can be adjusted to give flow rates up to 2.5 ml/min.

All electrical circuits are fitted with appropriate protection devices.

The console has two digital meters. The first, associated with the controller, shows the temperature of water supplied to the column jackets, and the second shows the optical sensor reading which provides a measure of product concentration. Corresponding signals are routed to the I/O port for connection to a PC.

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Instructional Capabilities

> Understanding the principles of packed bed catalytic reactors
> Mass balancing
> Examination of steady and unsteady state catalysis
> Comparison of chemical and biological (enzymic) catalysis
> Flow characterisation in a packed bed
> Understanding the principles of Flow Injection Analysis (FIA)

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Detailed Capabilities

Teaching exercises are included to familiarise students with the following topics:

> Determination of steady state and unsteady state kinetics of a packed bed catalytic reactor.

> Performance comparison of a chemical catalyst (protonated cationic exchange resin) with a biological catalyst (immobilised enzyme).

> Effect of catalyst particle size on the Thiele modulus and the effectiveness factor (quantification of the competitive effects that occur between reaction kinetics and mass transfer inside the catalytic particle).

> Effect of flow rate, temperature and feed concentration on steady state conversion.

> Tracer studies to characterise fluid flow within the reactors.

> Demonstration of the Flow Injection Analysis technique.

> Examination of the reproducibility and sensitivity of the FIA analysis method as a function of the flow rate and sample concentration.

CEU process flow sheet with optional third reactor and FIA system.

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Calibration curves for the optical sensor.

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Description

The CEU introduces students to the fundamentals of packed bed catalytic reactors. It is a bench-top unit available with either two or three reactor columns.

Using two columns with a chemical catalyst allows a different particle size exchange resin to be used in order to study the effect of particle size on reactor kinetics. It is possible to use a third column to investigate biological catalysis, using the enzyme invertase, and compare this with chemical catalysis.

An optional flow injection analysis (FIA) module is available. This module is positioned on the CEU plinth and provides an easy on-line measurement of product yield, eliminating the need for manual assays. The module is also useful for teaching the FIA technique and demonstrating the advantages of this measurement method in continuous processes.

CEU

The basic CEU comprises a vacuum-formed plinth with two packed bed reactor columns with provision to mount a third. It includes a hot water circulation system complete with temperature controller to maintain the desired reaction temperature.

The recommended reaction is the inversion of sucrose to form glucose and fructose. This is a safe and environmentally friendly reaction.

An optical absorbence sensor is provided to monitor the status of the reaction. With the basic system, samples are taken manually and inserted into the absorbence sensor using sample tubes.

A variable speed peristaltic feed pump controls the flow rate through the reactors.

Valves are provided to change the feed and product flow from one column to the other quickly and easily. This allows the student to investigate different reaction systems without having to dismantle the equipment and re-pack the columns.

CEU-3 Flow Injection Analysis

The FIA module is a self-contained sub-assembly which is located on the CEU plinth. The module contains a multi-channel pump and a multi-port valve.
The absorbence sensor from the CEU is repositioned on this module to allow on-line measurements to be taken. The FIA pump supplies a proportion of the product to the multi-port FIA valve. The pump also delivers assay reagent and the carrier liquid to facilitate the assay procedure. The FIA valve mixes the reagent and product in the correct ratios before the mixture is delivered to the optical sensor where the product yield is measured.

CEU-5 Third Reaction Column

An additional reactor may be specified which uses the same sucrose inversion reaction but an alternative biological, enzymic catalyst. This allows comparison between chemical and biological catalysts.

Note: Regular re-charging of the biological reactor column is required due to the less stable nature of this type of catalyst.

CEU-304IFD Educational Software and Data Logging Accessory

Example of educational software (CEU-304IFD)

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The sensor outputs are available for data logging and analysis. The Armfield data logger interfaces between the CEU and the user's computer using a USB port. The associated software includes graph plotting, full instructions on setting up the equipment and performing the investigations, related theory and full help texts. It requires a computer running Windows 98 or later with a USB port.

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