LPG is an alternative fuel, which is still fossil fuel-derived. It offers several benefits over traditional fuels as LPG is a clean-burning transport fuel with a high energy content and the infrastructure is well developed. The legislative rules and automotive industry promote the use of LPG.

One of the fuel specifications for LPG concerns the amounts of oily residues, as these lead to troublesome deposits and material changes. Conventional test methods that measure the oily residues require the evaporation of large amounts of LPG and therefore present a high safety risk. A new technique to determine the oily residues using a fast, safe and accurate method is based on Gas Chromatography combined with the Da Vinci Europe Liquefied Gas Injector (LGI).

• UPDATE!
  The GC analysis method ASTM D7756-11 ” Standard Test Method for Residues in Liquefied Petroleum (LP) Gases by Gas Chromatography with Liquid, On-Column injection” has recently been approved by ASTM.

How it Works

The Da Vinci LGI injects LPG under pressure and at room temperature direct on column. With this injector no vaporizer, transfer line or valve is needed and therefore there is no adsorption, discrimination and fractionation. The unique capabilities of the LGI make it possible to analyze and quantify a complex matrix of heavy boiling components in low boiling matrices.

After injection, the GC analysis technique uses a vapor exit to flush the LPG light end fraction. The oily residue remains on the column and is separated by boiling point order. The result is reported as concentration in mg/kg (mass ppm). The analysis range starts from 10 up to 600 mg/kg having a repeatability of 5%. The required analysis time is less than 30 minutes.

Repeatability 10 - 600 ppm (click for larger view)

Proven Technology

After the product introduction in 2010 the LGI was awarded “Best New Technology” at the 2010 Gulf Coast Conference. The current installed base includes LPG customers located in Africa, Australia, Asia, Europe and U.S.A. Their experiences with the LGI have proven that the new technology is safe, fast and accurate. Additional benefits are: the results are not only reported as a value in mg/kg, the chromatogram also indicates the composition of the contamination and helps tracing the source of contamination.

Features of the Liquefied Gas Injector:

• Meets the specifications for ASTM D7756-11
• Alternative for ASTM D2158, EN 15470, EN 15471 & ISO 13757
• No open air evaporation of LPG
• High pressure injection directly onto GC column up to 30 bar
• Prevents discrimination and fractionation
• Unique and user friendly design
• Accurate quantification of heavy residues
• Fast analysis time of 24 minutes
• Lowest detection limit of 1 mg/kg (mass ppm)
• Repeatability of 5%
• Sample size from 30 – 500 µL
• Analysis range from 10 – 600 mg/kg (mass ppm)

Envantage, Inc. is the Exclusive North American Distributor of the Da Vinci Europe Liquefied Gas Injector (LGI) on the Agilent Platform

For more information download our flyer:

Da Vinci Liquified Gas Injector (145)

The Da Vinci LGI injector was featured in the Petro Industry News article “A Safe and Fast Solution for Accurate Quantification of Heavy Residues in LPG by Gas Chromatography: Representative Liquefied Gas Sample Introduction via High Pressure On-Column Injection into a Gas Chromatographic System”

Click here to download the PIN article

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