Continuous distillation column experiment

CONTINUOUS DISTILLATIONCOLUMN - UOP3CC

A. INTRODUCTION TO THE EQUIPMENT

Distillation has always been and will continue to be one of the most important industrial processes for separating the different components of a liquid mixture. Laboratory scale distillation columns are needed to provide adequate practical training for student engineers and plant operators in a safe environment. They may also be used to acquire process separation data, of use in full-scale plant design.

The UOP3CC allows the study of both batch and continuous distillation, packed or plate column operation, operation under atmospheric pressure or under vacuum, azeotropic distillation, and manual, PID, PLC or computer control of the process. Data logging of the process is also possible.

UOP3CC Continuous Distillation Column

with computer control

Figure 1. Schematic Diagram of Apparatus

Figure 2. Diagram of Distillation Column

Figure 3. Diagram of UOP3CC Process Unit

Figure 4. Diagram of UOP3CC Console

B. DESCRIPTION

Where necessary, refer to the drawings on pages 19 to 22.

1. Overview

The UOP3CCContinuous Distillation Column is a self-contained distillation facility consisting of two interconnected units: a floor standing process unit and a bench mounted control console.

2. Floor-Standing Frame

The distillation column is mounted on a floor standing, welded tubular steel framework (1) fitted with four adjustable feet (2). The frame is designed to allow the use of a fork lift or pallet truck to manoeuvre the unit into position initially.

3. Distillation Column

The 50mm diameter sieve plate column is made up of two glass sections (3) and (4) each containing four sieve plates. The columns are separated by a central feed section and arranged vertically for counter-current vapor/liquid flow. The column is insulated to minimize heat loss.

The glass column incorporates a total of eight sieve plates in two sections (3) and (4) each containing four plates. Each plate (D) is located by a central support rod (E) and incorporates a weir (F) and downcomer (G) to create a liquid seal between successive stages. The liquid seal on the final plate in each section is achieved by U-tube (H).

Feed mixture from either of the feed tanks is pumped by pump (7) to the base, centre or top of the distillation column at connections (A), (B) or (C) respectively. The feed pump incorporates a length of Viton rubber tubing. This tubing is suitable for all of the recommended test mixtures (see “Operational Procedures”). Where other test mixtures are being used, the suitability of this material must be checked.

4. Reboiler

The reboiler (13) situated at the base of the column is manufactured from 316 stainless steel and incorporates a flame-proof immersion type heating element. Either batch or continuous distillation can be carried out using this reboiler.

In continuous operation, valve (V1) is open and bottom product flows from the reboiler through the bottom product cooler (15) to the bottom product tank (9). It is possible to preheat the feed to the column by directing the feed through a spiral coil in the bottom product cooler where heat is transferred from product leaving the reboiler at the boiling point. When feeding cold feed directly to the column, the product from the reboiler is cooled in the bottom product cooler by circulating cold water through the spiral coil.

For batch operation, valve (V1) remains closed so that the reboiler can be filled with the initial charge (10 to 12 litres) of binary mixture. The c