Analytical Analysis in Chemical Process Control Instrumentation and control Analytical Analysis in Chemical Process Control Dr. –Ing. Naveed Ramzan Department of Chemical Engineering, U.E.T. Lahore Pakistan 25. März 2017 / Dr. –Ing Naveed Ramzan 1 25. März 2017 / Dr. –Ing Naveed Ramzan 1

Purpose of Measuring Physical Properties - Control Product Quality Introduction Purpose of Measuring Physical Properties - Control Product Quality - Maintain Safe Operation - Process Optimization

Instruments for measurement of: Composition pH Viscosity Outline Instruments for measurement of: Composition pH Viscosity Optical properties

Composition Measurement: Analyzers in the Process Industry Reactor Control Environmental Monitoring Product Compositions Purpose Control of chemical processes Requirements Low Maintenance Simplicity “Ruggedness” Few or no moving parts

Challenges in Analyzer Design Exposure to corrosive environments Must withstand non-ideal concentrations of secondary components Maintenance only once every few months Reliability is key

Classification of Process Analyzers Nonspecific (Inexpensive) Specific (Costly) Liquid Liquid Gas Gas Thermal Conductivity Electrical Conductivity Gas Chromatography IR/UV-VIS Spectroscopy

Sampling Systems Sample Sample Conditioning Analyzer Extraction Process Stream Sample Return

In-line sampling On-line sampling Direct sampling in process line Sampling Systems In-line sampling Direct sampling in process line Advantage: no sampling delay Disadvantage: measurement affected by temperature and pressure variations On-line sampling Extract sample continuously and send to instrument Advantage: control of temperature, pressure Disadvantage: time lag before measurement

CHROMATOGRAPHY Chromatography basically involves the separation of mixtures due to differences in the distribution coefficient (equilibrium distribution) of sample components between 2 different phases. One of these phases is a mobile phase and the other is a stationary phase.

Concentration of component A in stationary phase Distribution Coefficient (Equilibrium Distribution ) Definition:   Different affinity of these 2 components to stationary phase causes the separation. Concentration of component A in stationary phase Concentration of component A in mobile phase

Kinds of Chromatography 1. Liquid Column Chromatography   2. Gas Liquid Chromatography 3. Thin-layer Chromatography

LIQUID COLUMN CHROMATOGRAPHY A sample mixture is passed through a column packed with solid particles which may or may not be coated with another liquid. With the proper solvents, packing conditions, some components in the sample will travel the column more slowly than others resulting in the desired separation.

Diagram of Simple Liquid Column Chromatography

FOUR BASIC LIQUID CHROMATOGRAPHY The 4 basic liquid chromatography modes are named according to the mechanism involved:  1. Liquid/Solid Chromatography (adsorption chromatography) A. Normal Phase LSC B. Reverse Phase LSC  2. Liquid/Liquid Chromatography (partition chromatography) A. Normal Phase LLC B. Reverse Phase LLC  3. Ion Exchange Chromatography  4. Gel Permeation Chromatography (exclusion chromatography)

Types of Chromatography

Schematic Diagram of Liquid Chromatography

High Performance Liquid Chromatography

High Performance Liquid Chromatography

Chromatogram of Organic Compounds from Fermented Cabbage

Chromatogram of Orange Juice Compounds

??? Questions 25. März 2017 / Dr. –Ing Naveed Ramzan 21