Analysis of Oxygenates, Paraffins, Naphthenes and Aromatics O-PNA in Hydrocarbon Streams

Contents

Introduction
Bruker PIONA+ GC
The PIONA+TM Analyzer
Analysis of Oxygenates, Paraffins, Naphthenes and Aromatics (O-PNA) of Hydrocarbon Streams
Results and Discussion of Sample Test
Conclusion

Introduction

Accurate and comprehensive analysis of exogenous and discrete elements in a wide range of sample matrices are key applications for many analytical chemistry groups and industries.

To address the needs and challenges of analysts working in these areas, Bruker has developed and expanded their product family to provide, and expertly support, a series of fully integrated solutions including:

  • Gas Chromatography-Mass Spectrometers (GC/MS and GC/MS/MS)
  • Inductively Coupled Plasma Mass Spectrometers (ICP-MS)
  • Gas Chromatography Systems (GC)

Widely used in food and consumer safety testing, forensic, industrial, environmental, and clinical laboratories, these systems are well accepted and established market leaders that universally deliver outstanding performance at a premium value.

Bruker PIONA+ GC

Standard GC Analyzers: Configured for Performance and Productivity

Bruker configures and tests its standard GC analyzers to more than meet industry standard performance requirements for a variety of widely used methods (ASTM, UOP, EN, ISO, GPA). Available in an array of configurations, Bruker Standard GC Analyzers utilize the leading analytical performance characteristics of the Bruker 400 Series of GC.

The PIONA+TM Analyzer

Image 1. The PIONA+  GC Analyzer

Using a fully automated multidimensional gas chromatography approach to analyze individual hydrocarbons groups per carbon number, the PIONA+ Analyzer is especially designed and configured to be fully compliant with any of the following established methods including: ASTM D6839, EN-ISO-22854, ASTM D5443, ASTM D1319, IP-382, IP-526, EN 14157, UOP 870 and DIN-51448.

Concurrent Operation Ramps-Up Productivity

The PIONA+ Analyzer is capable of concurrent use of molecular sieve columns and carefully matched temperature programming to provide simultaneous separation of Napthalenes, iso-Paraffins, and normal Paraffins by carbon number in carbon number ranging from C4 through C11. With a traditional PIONA analysis, this separation would normally take around 180 minutes.

Taking advantage of the capabilities of the PIONA+ Analyzer reduces the analysis time by almost half-down to only 95 minutes. For some analyses, such as for gasoline with ether additives, the analysis time can be reduced even further down to 65 minutes and provide results conforming with ASTM D6839.

Making Total Olefin Content Analysis Practical

The PIONA+ Analyzer provides a powerful simplified approach for a notoriously difficult operation-that of total olefin analysis. The stability, sample loading capacity, and lifetime of the PIONA+ Analyzer have all been dramatically enhanced to meet the needs of olefin analysis.

Particularly important is the increased capacity of the "olefin trap" of the PIONA+ Analyzer. With this enhanced capability, it's possible to analyze streams with olefin content as high as 35-40% or more.

Analysis of Oxygenates, Paraffins, Naphthenes and Aromatics (O-PNA) of Hydrocarbon Streams

The Bruker PIONA+ Analyzer is a comprehensive GC system that offers the ability to characterize and quantify components in a variety of spark ignition fuels according to an array of industry standard method protocols. For quantitative determination of oxygenates, Paraffins, naphthenes and aromatics (O-PNA) in spark ignition fuels the PIONA+ uses a multidimensional gas chromatography separation approach. The system can be operated in one of multiple method “modes” depending on the analysis requirement of a given stream type.

For this particular application, the system was set up in O-PNA mode and used to characterize the oxygenate, paraffin, naphthene and aromatic content of spark ignition fuels.

Using the Bruker PIONA+ Analyzer incorporating compassCDS Chromatography Software and PIONA+ Software Plug-in it is possible to accurately identify and characterize the O-PNA make-up of spark ignition fuels.

Figure 1. A Chromatogram of test sample 1 spiked with oxygenate

Test Conditions

All conditions for the different columns and traps were set in order to obtain the elution scheme represented in Table 1.

Table 1. Elution Scheme for O-PNA

From To (min) Components Column Route
0 25.0 C1 to C10 N + P 1st OV-275 fraction via arom/eth and
olefin trap to 13x
25.0 30.0 >185 °C fraction Back flush non-polar column of 2nd
 OV-275 fraction
30.0 40.0 ethers 1st OV-275 fraction via arom/eth and non-polar
to porous polymer column
40.0 45.0 C8 A and pN 2nd OV-275 fraction via arom/eth and non-polar
column
45.0 50.0 >185 °C fraction Back flush non-polar column of 2nd
OV-275 fraction
50.0 60.0 C6 A + C7 A 2nd OV-275 fraction via arom/eth and non-polar 
to porous polymer column
60.0 66.5 Ca to C10 A 3rd back flush OV-275 and precolumn back flush
fraction via arom/eth to non-polar column
66.5 75.0 >185 °C fraction Back flush non-polar column of 3rd OV-275 and
pre back flush fraction
75.0 85.0 alcohols 3rd OV-275 and precolumn back flush fraction
via arom/eth and non-polar to porous polymer
column

Results and Discussion of Sample Test

When all columns and traps are set in the O-PNA mode required settings, a chromatogram according to the elution scheme in Table 1 is obtained. In this case, a chromatogram of test sample 1 spiked with oxygenates is shown. The Bruker PIONA+ Analyzer is preset with a number of reports, as shown in Tables 2 and 3.

Table 2. Mass% results of test sample 1 - Normalized Weight Percent Profile

Carbon Naphthenes Paraffine Aromatics Oxygenates Total
2 0.00 0.00 0.00 3.92 3.92
3 0.00 0.00 0.00 0.00 0.00
4 0.00 0.00 0.00 0.00 0.00
5 0.00 0.00 0.00 8.18 8.18
6 1.87 2.45 2.18 0.00 6.51
7 4.65 4.12 2.09 0.00 10.86
8 4.89 70.19 9.42 0.00 21.50
9 4.07 2.97 6.21 0.00 13.25
10 2.27 4.59 5.18 0.00 12.04
11 0.00 0.00 0.00 0.00 0.00
Total 17.76 21.34 25.09 12.11 76.29
           
Fraction >200°C 18.31   MTBE 8.18
Polynaphthenes 5.40   Ethanol 3.92

Table 3. Volume % profile of test sample 1 - Normalized Volume Percent Profile

Carbon Naphthenes Paraffine Aromatics Oxygenates Total
2 0.00 0.00 0.00 3.95 3.95
3 0.00 0.00 0.00 0.00 0.00
4 0.00 0.00 0.00 0.00 0.00
5 0.00 0.00 0.00 8.78 8.78
6 1.97 2.96 1.97 0.00 6.90
7 4.88 4.78 1.92 0.00 11.58
8 5.01 8.12 8.64 0.00 21.76
9 4.11 3.26 5.65 0.00 13.02
10 2.23 5.00 4.64 0.00 11.87
11 0.00 0.00 0.00 0.00 0.00
Total 18.20 24.15 22.83 12.73 77.90
           
Fraction >200°C 16.27   MTBE 8.78
Polynaphthenes 5.83   Ethanol 3.95

In Figure 2, a chromatogram of a gasoline is shown. Again, a clear overview of the group type separation per carbon number and the oxygenates is revealed, in this case only MTBE. From this chromatogram volume and weight percent profile reports are generated.

Figure 2. A Sample chromatogram of a gasoline.

The reports are divided into several columns with saturated and unsaturated component groups. Furthermore, a clear overview per carbon number is produced as well as the totals per group and per carbon number. Finally, the oxygenates are reported per carbon number and as individual components (Tables 4 and 5).

Table 4. Weight % profile of Gasoline - Normalized Weight Percent Profile

Carbon Naphthenes Paraffine Aromatics Oxygenates Total
2 0.00 0.00 0.00 0.00 0.00
3 0.00 0.00 0.00 0.00 0.00
4 0.00 1.15 0.00 0.00 1.15
5 0.30 11.99 0.00 4.66 16.95
6 1.64 9.43 1.04 0.00 12.11
7 2.41 8.97 11.49 0.00 22.87
8 1.63 5.39 20.15 0.00 27.17
9 0.70 1.96 11.59 0.00 14.25
10 0.18 0.47 3.07 0.00 3.72
11 0.00 0.00 0.00 0.00 0.00
Total 6.85 39.36 47.33 4.66 98.21
           
Fraction >200°C 1.75   MTBE 4.66
Polynaphthenes 0.04      

Table 5. Volume % profile of Gasoline - Normalized Volume Percent Profile

Carbon Naphthenes Paraffine Aromatics Oxygenates Total
2 0.00 0.00 0.00 0.00 0.00
3 0.00 0.00 0.00 0.00 0.00
4 0.00 1.52 0.00 0.00 1.52
5 0.30 14.65 0.00 4.79 19.74
6 1.65 10.91 0.90 0.00 13.46
7 2.42 9.98 10.09 0.00 22.49
8 1.60 5.83 17.70 0.00 25.12
9 0.68 2.06 10.11 0.00 12.85
10 0.17 0.49 2.63 0.00 3.29
11 0.00 0.00 0.00 0.00 0.00
Total 6.81 45.43 41.43 4.79 98.47
           
Fraction >200°C 1.49   MTBE 4.79
Polynaphthenes 0.04      

Conclusion

This article describes the determination of oxygenates, paraffins, naphthenes and aromatics with the Bruker PIONA+ analyzer. This analyzer provides the required mass% and volume% reports and functions fully according the ASTM methods D 6839 and D 6293.


This information has been sourced and adapated from Information provided by Bruker. For more information please contact Bruker

Comments

  1. Pedro Ortega osuna Pedro Ortega osuna Bolivarian Republic of Venezuela says:

    I would like a recommendation to analyze the content of aromatics in white mineral oils, with the equipment easiest to operate.

The opinions expressed here are the views of the writer and do not necessarily reflect the views and opinions of AZoM.com.

Ask A Question

Do you have a question you'd like to ask regarding this article?

Leave your feedback
Submit