Gas chromatography practical approach2

Gas ChromatographyA practical approach

Martin van Burgh, MP Seminar, 13-03-2011

Why use a gas chromatograph

Typical measurements: Most samples vaporize below 450º C without cracking Analyzer specialists and technicians are available Requirements are well defined

Most separations can usually be found that eliminate interference

The range of detectors, both sensitive and selective

Broad range of applications Most versatile process analyzer

Month DD, Year | Slide 2© ABB Group

ABB Process Gas Chromatographs


Introduction

Developed in parallel to lab GC’s – mid 1950’s Users partnered with lab suppliers & others

Union Carbide - Watts Mfg in Ronceverte, WV Phillips Petroleum - Perkin-Elmer in Norwalk, CT

1957 Watts product bought by Beckman Greenbrier Instruments founded

1960’s Bendix Environmental and Process Instruments Division

1970’s Combustion Engineering

1990’s ABB


GC Diagram


Injection Valve

Source: Linde Gas

Column

Detector

Sliding Plate

Accommodates packed or capillary columns

Automatic wear compensation and slider tension loading

Samples up to 150 PSI and 180 C

Diaphragm

Accommodates packed or capillary columns


ValvesGas Valves


791 LSV

Wear Compensating Seals

Metal Surface deactivation


Rotary Valve

High Temperature valves available.

Samples up to 1.000 PSI and 175C

ValvesLiquid Valves


Type of columns

Packed Columns Efficiently separates lighter gas-phase samples

(typically molecular weights less than n-hexane) Typical internal diameters are 1/8, 3/16, or 1/4 in

(2, 3, or 4 mm) with 1/16 in (0.7 mm) for high speed applications

Capillary Columns (Open Tube) Efficiently separate high-molecular-weight

samples which are liquids at ambient temperature

Typical internal diameters are 0.25 mm with an increase in popularity of megabore (0.35-0.50 mm)

Increased speed of analysis Better component resolution Enhanced trace measurement


Gas – Liquid Chromatography


Seperation - Partitioning


Columns

Seperates on molweight and vapor pressure Smaller molecules generally have higher vapor pressure

and tend to leave the stationary phase earlier. Used mostly in light gas applications (C1 – C4)

Boiling point


Columns

Non-Polar Polar

Octane Methanol

Benzene Chloroform

Toluene Acetic Acid

Polarity


Columns

Seperates based on molecular size. Contains zeolites with a known pore size distribution

(sieve) Most known type 5A Most used for seperation of CO, CH4, N2, O2 Smaller molecules go easily through the pores, where big

molecules need more time. Large molecules will poison the column by blocking the

pores.

Mol Sieve


Columns

Columns nowadays are a combination of different techniques.

Example Hayesep N, Hayesep Q, Hayesep T Vendors of columns market their columns based on

applications.

Overview


Detectors

Discharge Ionization Detector (DID) Electron Capture Detector (ECD) Flame Photometric Detector (FPD) Flame Ionization Detector (FID) Infrared Detector (IRD) Mass Spectrometer (MS) Photo Ionization Detector (PID) Thermal Conductivity Detector (TCD)

Just a selection…


DetectorsThermal Conductivity


Universal response Minimum detectable

quantity = ~10 ppm Nondestructive Good linearity

DetectorsThermal Conductivity


DetectorsFlame Ionization Detector




Selective response – organics

Minimum detectable quantity = ~100 ppb

Destructive Good linearity and stability



DetectorsFlame Photometric Detector


Highly sensitive, low PPM level

Sulfur detection only Built in “background sulfur

addition” Task dedicated

electrometer with sulfur response linearization

Automatic re-ignition - standard

DetectorsFlame Photometric Detector


DBDIDhalogenated hydrocarbons

impurities in ethylene

low levels of BTX

arsine and phosphine

ethylene oxide

ammonia

PIDnitric oxide

nitrogen dioxides

alkenes

aromatics

halogenated hydrocarbons

arsine and phosphine

DetectorsIonization Detectors


Oven ConfigurationSimple Analysis


Oven ConfigurationComplex Analysis


The PGC5000 Series Analyzer System

PGC5000B Smart OvenTM

Targets simple applications with a fixed set of features

Maximum application flexibility

© ABB Group May 3, 2023 | Slide 26

PGC5000A Master ControllerImproves “Ease of Use” with a new graphics based HMICommunication interfaces: Ethernet, OPC, MODBUS, 4-20mA

analogs, VistaNET2.0 compatibleSupports up to 4 Smart OvensTM

PGC5000C Smart OvenTM

Targets complex applications requiring multiple detectors

Maximum application densification28% larger oven volume

PGC5000A Master Controller 10.4 inch Super VGA Graphical Driven HMI with standard keypad

and mouse touch pad Optimum visibility and resolution of the NEW Graphical User

Interface Color graphics allow for a highly visible indication of event and

status change in the analyzer system Allows for a highly graphical representation of each process

stream's analysis with local chromatogram overlay


PGC5000A Master Controller – Standard

Single programmable common malfunction alarm Dry contact relay, 30 VDC, 1A

Redundant network communication Ethernet (copper standard, fiber optional) Modbus TCP/IP (TCP/IP standard, serial optional)


PGC5000A Master Controller – Internal I/O


These optional I/O modules are installed in the SBC card cage

Additional/Extended I/O is installed within the PGC5000A controller up to a maximum of 4 I/O modules and up to a maximum of 32 I/O points depending on I/O type

PGC5000A Master Controller – Internal I/O


Power to the I/O controller and bus comes from main PGC5000A power supply

PGC5000 communication comes from the oven controller over copper CAN to the I/O controller

End Module

I/O Modules

I/O Controller

PGC5000A Master Controller – External I/O When more than the maximum of 4 I/O modules inside the PGC5000A is

required, I/O can be further expanded remotely All components are Division 2/Zone II by design; Div 1/Zone 1 area

classification requires the enclosure to be simple Y-purged


Fiber Optic NEMA 4 Enclosure

Extended External I/O is installed within a remote NEMA 4 enclosure up to a maximum of 32 I/O modules and 256 I/O points depending on I/O type

PGC5000 Smart Oven™ Technology


Electronics Section

Analytical Oven Section

Flow Control Section

Designed for simple applications or for making complex applications simple!

PGC5000 Smart Oven™ Technology – Standard

1 programmable common malfunction alarm Dry contact relay, 30 VDC, 1A

1 additional dry contact Loss of purge

16 digital inputs 5 VDC, 1mA


PGC5000B PGC5000C

PGC5000B Smart Oven™ Solenoid Valves

Base: 3 Air Switching Valves Internal analytical valve control

Optional: 10 Air Switching Valves External SHS valve control

Detectors One detector maximum – sTCD, mTCD, FID, and FPD

DTC 3 digital temperature zones

EPC 5 electronic pressure zones


PGC5000C Smart Oven™

Solenoid Valves Base: 6 Air Switching Valves

Internal analytical valve control

Optional: 10 Air Switching Valves External SHS valve control

Detectors Two detectors maximum – sTCD, mTCD, FID, and FPD

DTC 3 digital temperature zones

EPC 10 electronic pressure zones


Optional Stream Switching Solenoids


Additional optional stream switching valves (shown in white) are available up to a maximum of 10• The 3 shown in green are the

standard analytical valve switching solenoids for the B class oven

Optional External Stream Switching Solenoids


Extended, external I/O includes remote stream switching solenoids up to a maximum of 32

F/O CAN communication from the PGC5000 is converted to copper CAN for communication to I/O and remote stream switching solenoids

The extended, external I/O illustration above represents the maximum configuration per enclosure: 32 I/O modules and 32 stream switching solenoids

Optional External Stream Switching Solenoids Used to support larger numbers of

stream solenoids Ambient air analyses Multiplexing stream applications


Burkert AIRLINE Solenoid Valves

Propylene Purity Application Single Oven

SBFV SBFV

SEL

SBFV SBFV

FID

TCD

methanizer

Ref. Low ppm H2

Mea. % C3H8

ppm C0,C02

ppm MeOH

Multiple Oven Approach

SBFV TCD

SBFV

Ref. Low ppm H2

Meas. % C3H8

SBFV Methanizer FID

SBFV SELppm MeOH

ppm CO,CO2

Oven 1

Oven 2

Oven 1

Oven 2

Animated View

Application Review and quotation

Complete Stream Data Undefined compounds can present interferences on

the chromatogram, possibly introducing errors into the measured components

Measured components with ranges Sample Phase

Liquid Vapor

Any known unique or special sample chemistry Process service description Special requests

Identical applications Application requests

05/03/23 42

How ABB uses this information

Application feasibility check Review of the requested measurements and ranges in

the streams’ matrices Determine hardware and configuration necessary for

the component separation and measurement Valve(s)

Column(s)

Detector(s)

Determine the cycle time necessary for component resolution

Calculate the optimum component repeatability Identify any exceptions the request or alternative

solutions

05/03/23 43

Factory Application Set-up

Program analyzer with the analytical method for chromatographic separation and measurement of components

Verify measurements are free of potential interferences Program component name and ranges Calibrate the analyzer Run stability tests


Field Set-up

Connect power and outputs Turn power and purge gases on Allow analyzer temperatures and purges to stabilize Set the column flow rates according to the analyzer data

package Connect analyzer to calibration samples and process

stream Calibrate the analyzer Put the process stream through the analyzer
