Envantage da vinci_lgi_gcc2011

Improving the analytical precision for

the analysis of contaminants in liquefied gases

GCC 2011

Jay Grills – Envantage Lenny Kouwenhoven - Da Vinci Europe

Contaminants in liquefied gases

• Oily residues in LPG• P-Tertiary-Butylcatechol in

Butadiene• Elemental Sulfur in LPG• DIPA in LPG

phthalate esters

Current methodsEN 589:2008

• EN 13757: Liquefied Petroleum gases -Determination of oily residues -High-temperature method

• EN 15470: Liquefied petroleum gases - Determination of dissolved residues - High temperature Gas chromatographic method

• EN 15471: Liquefied petroleum gases - Determination of dissolved residues - High-temperature gravimetric method

ASTM D1835• D2158:Standard Test Method for Residues in Liquefied

Petroleum (LP) GasesASTM D1157: Total inhibitor content (TBC) of Light

Hydrocarbons

LSV or GSV?

• No deposit of high boilers before the column

• Flash of the sample in the column

• Injection under pressure in liquid phase

GC Injector based on GDI“Gasoline direct injector”

Gasoline Direct Injectordevelopment of Shell Global Solutions

Alternative based on GCa new type of GC injector

A Gasoline direct injector…..

Mounted on a slide and connected to a needle….

Injects liquefied gases directly on-column!

1 2 3

P

Waste

Sample in

Sample cylinder

Sample out

GCrotameter

vaporizer

GDI

Cool on column

Pressure station the sample manager

Solvent vent valve

Cool on-column inlet

Retaining precolumn

Column splitter

Detector

Retention gap Analytical column

Application overview COC inlet

Retention Gap

Retaining Pre- Column

Solvent vent

Analytical Column

FID

Problems of Oily Residue for the Automotive Industry

Blisters containing oily residues

Abrasion and disgregation of thematerial

Oily Residue analysis in LPG

• C10-C40; 174°C-522°C; °F-°F

• 10-600 mg/kg

• GC Configuration: COC – solvent vent – boiling point column FID

• Injection volume: 25 ms ( 30µl)

ASTM D7756

C10 C20C30

C40

N-Alkane standard

Repeatability

Precision D2158

Precision D7756Residue GC method

Precision D 7756Residue GC method

Concentration (mg/kg)

Repeatability Relative Standard deviation

10.3 1.2 4.0 %

51.3 5.3 3.8 %

103 8.3 2.9 %

302 14.5 2.4 %

602 14.4 3.1 %

P-TBC in Butadiene

• Oxidation inhibitor

• Butadiene is extremely flammable and a suspected human carcinogen

• ASTM D1157: evaporation of 100ml measuring the absorbance using a photoelectric photometer after adding FeCL3

Overlay of 6 chromatograms

Linearity of p-TBC by GC

Precision ASTM D1157

Precision p-TBC by GC

pTBC concentration in

mg/kg

Relative standard deviation

36 2.4%120 3.3%241 3.0%361 1.6%482 3.3%602 4.0%

diisopropanolamine (DIPA)

Desulfurization

0,9 ppm Elemental S

Area: ~40.000

S8

Conclusion

The Liquefied Gas Injector is an alternative for the evaporative methods for high boiling components in low boiling matrices

Improved precision

Faster analysis

&

Safe!