Post on 15-Mar-2020
Liquid Injection valve testing for Micro-GC adaptation
IFPAC – 2012
Ramy Abou Naccoul, Ph.D. Claude Bernard University Lyon
*Claude Bernard University, LSA team – **SRA instruments, + IFPEN, France
LSA/TAP - IFPAC 2012 - Baltimore MD
V. Malicet*, I. Mokbel*, R. Cozic**, J. Jose*, F. Baco-Antoniali+
LSA/TAP - IFPAC 2012 - Baltimore MD
Context: needs of micro-analyzers and micro-sensors
Difficulties to implement on industrial sites and R&D laboratories, because of:
- Unsatisfactory accordance between analyzers and industrials needs
- Some laboratories techniques not adapted for in situ application
Problematic of the existing micro-analyzers and micro-sensors:
To analyze at the closest of the process, needs are:
- micro analyzers, micro sensors
- coupled with sampling microsystems
directly integrated into the process
Instrumentalists
Laboratories
Industries
LSA/TAP - IFPAC 2012 - Baltimore MD
How to answer to the needs for micro analysis?
Project “INnovAL”
INDUSTRIES (Arkema, Rhodia, Bluestar, Perstrop, IFPEN) Request – Validation - Optimization
LABORATORIES (University Lyon) Ecole des Mines (St Etienne)
Research
INSTRUMENTALISTS (SRA, EIF) Development & Industrialization
LSA/TAP - IFPAC 2012 - Baltimore MD
University of Lyon : Our contribution in the INnovAL Project: Development of liquid sampling-vaporization system for μGC Development of a μGC for on line analysis of liquid (available only
for gas analysis because of the temperature limit of the injector: < 100°C)
Optimization of micro-sensors
Density, particles ...
Comparison of the performance of the two online sampling/injection systems
• Heated Pressurized Liquid Injection System HPLIS (from SRA) • Rapid On Line Sampling Injector ROLSI (from EIF)
The comparison between the 2 valves is carried out using a synthetic mixture of n-alkanes and by studying:
• Chromatographic Repeatability • Existence of discrimination between the alkanes
Advantages and limitation of each sampling system
Function of : • Temperature • Pressure
LSA/TAP - IFPAC 2012 - Baltimore MD
The aim of the study : Find the most suitable liquid valve , optimize and couple to the micro-GC
Moving partCarrier gaz inlet
Cappillary
Vaporisation chamber
Carrier gaz outlet Cooling fan
Spring
Electromagnet
Soft iron Core
ROLSI valve
Specification : • Maximum operating pressure 300 bar • Maximum operating temperature 250 °C • Transfer line upstream the GC, 300°C • Adjustable injection volume
LSA/TAP - IFPAC 2012 - Baltimore MD
HPLIS
Specification : • Maximum operating pressure 80 bar • Maximum operating temperature 220 °C • Sample volume 0.06 μL • HStem 350 °C
LSA/TAP - IFPAC 2012 - Baltimore MD
HPLIS Valve Response of the HPLIS valve as a function of the temperature of the valve chamber
(at constant injection pressure = 6 bar )
Oven
Initial temperature
Final temperature
Time
50 oC 1 min 40 oC/min 320 oC 30 min
Carrier flow 1.1 ml/min FID temperature 320 oC
Injector temperature 280 °C
LSA/TAP - IFPAC 2012 - Baltimore MD
Conclusion: discrimination between the alkanes due to the low t°C max of the valve chamber (joint)
PTFE joint were replaced by glass-PTFE joint
HPLIS Valve
Conclusion:
*Pressure dependence was observed
*increase of 1.7% of the peak area
per 1 bar of pressure increase (PTFE)
*no dependence when using
glass-PTFE
LSA/TAP - IFPAC 2012 - Baltimore MD
Response of the HPLIS valve as a function of the upstream liquid pressure: 15 to 40 bars
HPLIS and fast-GC HPLIS has been tested in fast-GC configuration in order to simulate the Micro-GC conditions
A synthetic mixture of n-alkanes is used at atmospheric pressure
Column DB-1 : L=20m, I.D=0.1mm, 0.1μm Carrier gas : Hydrogen
Conclusion: shorter time of analysis (12 minutes gain) but same discrimination phenomenon than with normal GC
LSA/TAP - IFPAC 2012 - Baltimore MD
ROLSI valve n-alkane mixture between n-C8 and n-C16 at different injection pressures
valve chamber : 230 °C Transfer Line : 240°C
Pressures : 16 – 25 – 38 – 75 – 100 bar
LSA/TAP - IFPAC 2012 - Baltimore MD Conclusion: Discrimination between the alkanes independent from liquid pressure
ROLSI valve Discrimination study versus the valve chamber temperature
Three temperatures were tested 180, 220, 250°C using a synthetic mixture of n-alkanes
LSA/TAP - IFPAC 2012 - Baltimore MD Conclusion: the temperature of the valve has no effect on the discrimination
ROLSI Vs HPLIS A synthetic mixture of n-alkanes between n-C8 and n-C38 is used to evaluate the
performance of HPLIS and ROLSI at different pressures and temperatures
LSA/TAP - IFPAC 2012 - Baltimore MD
HPLIS • Discrimination independent from injection pressure • Temperature limitation to 220°C (normal PTFE joints) • Temperature limitation to 300°C (PTFE-glass joints) • Contamination of the core
ROLSI • Discrimination independent from injection pressure • Temperature up to 250°C • Long transfer line • Adjustable sampling volume
Perspectives ROLSI
• Installation of the ROLSI valve directly on the GC injector, elimination of the transfer line
• Increase the temperature of the ROLSI’s injection chamber, isolation of the valve chamber from the core
• Injection of alkane mixture in Fast GC configuration HPLIS
• Direct connection of the valve to the column (bypassing the GC split injector) • Test of new gasket (based on Vespel) to increase pressure and heat of the valve:
decrease discrimination • Injection of high boiling point mixture (efficiency of the flash heating)
LSA/TAP - IFPAC 2012 - Baltimore MD
In the frame work of a PhD thesis : • Improvements of Rolsi and HPLIS valves • conception, built and trial of a new liquid injection valve and adaptation to μGC
How ?
Perspectives
LSA/TAP - IFPAC 2012 - Baltimore MD
Liquid injection
Valve
Micro GC
Micro G
C SRA
Moving partCarrier gaz inlet
Cappillary
Vaporisation chamber
Carrier gaz outlet Cooling fan
Spring
Electromagnet
Soft iron Core
Objective : Place the injection valve and the Micro GC on the ASTUTE platform from EIF
Instrumentalists
Laboratories
Industries
LSA/TAP - IFPAC 2012 - Baltimore MD
INDUSTRIES (IFPEN, Arkema, Rhodia, Bluestar, Perstrop) Request – Validation - Optimization
LABORATORIES (University Lyon) Ecole des Mines (St Etienne)
Research
INSTRUMENTALISTS (SRA, EIF) Development & Industrialization
Thank you for your attention