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2017 | Buch

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Practical Column Design Guide

verfasst von: Dr. M. Nitsche, R. Gbadamosi

Verlag: Springer International Publishing

Enthalten in: Springer Professional "Wirtschaft+Technik" , Springer Professional "Technik"

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Über dieses Buch

This book highlights the aspects that need to be considered when designing distillation columns in practice. It discusses the influencing parameters as well as the equations governing them, and presents several numerical examples. The book is intended both for experienced designers and for those who are new to the subject.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Planning of Distillation and Absorption Columns

Abstract

First, this chapter presents general information on the planning of a distillation column. It then introduces the prerequisite for the planning of a distillation or absorption plant, particularly the physical data and the vapour–liquid equilibrium of the components involved. The chapter shows how to prepare a mass and energy balance for the desired separation. It covers fixing the separation conditions according to the available heating and cooling media. The general criteria for selecting equipment parts for the given problem definition is provided. The equipment parts are as follows:

appropriate column internals for the separation problem
condensers, reboilers and vacuum pumps
control equipment according to the requirements
heating with steam or thermal oil
cooling with cooling water or air

M. Nitsche, R. Gbadamosi

Chapter 2. Equilibria, Bubble Points, Dewpoints, Flash Calculations, and Activity Coefficients

Abstract

In this chapter, phase equilibria are covered in depth, backed up with several worked examples. It shows that the bases for all vapour–liquid equilibria are the vapour pressures of the components. Bubble and dew points, i.e. bubble and dew lines are calculated using the vapour pressures and the flash curves as function of the temperature. With non-ideal mixtures, the activity coefficient is considered.

M. Nitsche, R. Gbadamosi

Chapter 3. Fractionation of Binary Mixtures

Abstract

Based on the mass balance and the vapour–liquid equilibrium, the number of necessary stages for the separation and the required reflux ratio are determined using graphical and calculation methods. A shortcut method is given for a quick estimation. The influence of the thermal condition of the feed product on the separation and the column loading is discussed.

M. Nitsche, R. Gbadamosi

Chapter 4. Calculation of Multi-component Fractionation Plants

Abstract

For the given separation task, the number of stages, reflux ratio and column loading are determined based on the relative volatilities for the individual components. Additionally, it is shown how the compositions on the stages are calculated.

M. Nitsche, R. Gbadamosi

Chapter 5. Extractive and Azeotropic Distillation

Abstract

In extractive distillations, the volatility of the light boiling component is increased using a washing medium in order to improve the separation. In heterogeneous azeotropic mixtures with miscibility gap, the different concentrations in both liquid phases are utilized for the separation. Homogeneous azeotropic mixtures are separated by introducing an entrainer so that the condensate separates into two phases. A heterogeneous azeotrop is created. All these are covered in this chapter.

M. Nitsche, R. Gbadamosi

Chapter 6. Discontinuous Batch Distillation

Abstract

In this chapter, batch distillation is covered. The design of a batch distillation is difficult because the composition in the batch continuously changes during the course of the distillation. The separation becomes more difficult if the concentration of the light boiler in the batch gets smaller.

The reflux ratio must be increased.

The technical equipment must allow a flexible operation.

These are all treated in this chapter.

M. Nitsche, R. Gbadamosi

Chapter 7. Steam Distillation

Abstract

This chapter gives a deep insight in steam distillation design. With the steam distillation, the boiling point of high boilers is reduced. The steam is used as carrier medium for non-water-miscible components. The condensate of water and organic media is separated in a decanter. These and many other important aspects are covered in this chapter.

M. Nitsche, R. Gbadamosi

Chapter 8. Absorption and Stripping Columns

Abstract

This chapter covers all important aspects of absorption and desorption columns. Based on the equilibrium between gas and liquid, the required stages for a gas washer or a stripper are determined graphically or by calculation as a function of the washing medium or the strip gas rate. The specific features of air, vapour, ammonia and sour gas strippers are also covered.

M. Nitsche, R. Gbadamosi

Chapter 9. Fluid Dynamic Dimensioning of Trays and Tray Efficiency

Abstract

This chapter covers fluid dynamic design of tray columns. The correct design for the determined vapour and liquid flows is decisive. Large entrainment of droplets at high gas loading or weeping at low gas loading or flooding by downcomer backup must be avoided. It is shown how to determine the pressure loss and the stage efficiency.

M. Nitsche, R. Gbadamosi

Chapter 10. Fluid Dynamic Design of Random Packings and Structured Packings and the Determination of the HTU/HETP Values

Abstract

In this chapter, fluid dynamic design of packings and packed columns is covered. The prerequisite for a good separation effect is a good liquid and gas distribution. The pressure loss for different packings is calculated as a function of the gas velocity and the irrigation rate. The HTU values are calculated using three various models. The effect of different packings on the HETP value and the pressure loss is shown in an example.

M. Nitsche, R. Gbadamosi

Chapter 11. Demister Design

Abstract

In this chapter, demister is covered.

The allowable flow velocity in vertical and horizontal demisters is determined.

The special features for demisters at high pressures are also covered.

Very small droplets are separated by a droplet enlargement.

The falling velocity of droplets in gas is determined.

M. Nitsche, R. Gbadamosi

Titel: Practical Column Design Guide
verfasst von: Dr. M. Nitsche
R. Gbadamosi
Verlag: Springer International Publishing
Electronic ISBN: 978-3-319-51688-2
Print ISBN: 978-3-319-51687-5
DOI: https://doi.org/10.1007/978-3-319-51688-2

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